17 January 2022: Textbook Updates

We have posted updates of the following topics:

Bone & joints > Other chondrogenic tumors > Subungual exostosis
by Anshu Bandhlish, M.D., Jose G. Mantilla, M.D.
Topic summary: Rare, benign osteocartilaginous lesion arising from the distal phalangeal bone below the nailbed, lacking connection between the stalk of the lesion and medullary cavity of the native bone. More than 50% of cases are in patients younger than 18 years (average age: 25.7 years). Local recurrence is seen in cases after incomplete excision in approximately 4% of cases; no malignant transformation or metastasis has been reported. Complete marginal excision with minimal trauma to the nailbed is the optimal treatment.

CNS nontumor > Infections > Acute bacterial infections > Abscess
by Dennis K. Burns, M.D.
Topic summary: Localized, space occupying lesion within the brain composed of purulent (neutrophil rich) exudate and other inflammatory cells reacting to the presence of bacteria within the CNS parenchyma. Streptococcus spp. are the most common pathogens, although a wide range of organisms can cause disease; culture negative cases are not uncommon. Mortality ~10% in developed countries; old age, delayed diagnosis and treatment, ventricular rupture, rapid progression of symptoms and coma associated with poorer prognosis. Optimum management involves multidisciplinary approach (neurosurgery, infectious disease, neuroradiology, pathology and neurology).

Coagulation > Coagulation laboratory tests > PT / INR and aPTT
by Tori Seasor, M.D., Karen A. Moser, M.D.
Topic summary: Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are common initial tests in the evaluation of patients with suspected bleeding disorders. International normalized ratio (INR) is a calculation allowing for the standardization and comparison of PT clotting time results between laboratories. PT testing can be used clinically for evaluation of bleeding, assessment of liver disease, screening evaluation of factors II, V, VII, X and fibrinogen; aPTT testing can be used clinically for monitoring heparin and certain direct thrombin inhibitor therapy, screening evaluation of factors II, V, VIII, IX, XI, XII, fibrinogen, prekallikrein and HMWK, screening for lupus anticoagulant (lupus sensitive aPTT reagents).

Colon > Noninfectious colitis > Eosinophilic gastroenterocolitis
by Byoung Uk Park, M.D., Lizhi Zhang, M.D.
Topic summary: Eosinophilic gastroenterocolitis (EGEC) is an inflammatory disorder characterized by prominent eosinophilic infiltration of the gastrointestinal tract (stomach, duodenum, small intestine or large intestine) with no known causes of tissue eosinophilia. Overall prevalence of eosinophilic gastroenteritis in the U.S. is 5.1/100,000; more prevalent in the younger population (18 years or younger). Prognostic factors unknown due to the rarity of the disease but observed to be dependent on response to treatment and Klein classification of disease. No established standard treatment guidelines are available; current treatments are based on case reports and case series.

Transfusion medicine > Transfusion therapy > Sickle cell disease
by Yvette C. Tanhehco, Ph.D., M.D., M.S.
Topic summary: A hemoglobinopathy caused by a point mutation in the β globin gene that leads to the production of hemoglobin S, which polymerizes under deoxygenated conditions and causes red blood cells (RBCs) to form a sickle shape. Sickle RBCs are rigid and less deformable, which causes vaso-occlusive pain crises, hemolytic anemia, endothelial injury and inflammation. Pathophysiology: single point mutation (A to T substitution) in the first exon of the β globin gene, converting glutamic acid into valine. Transmission: autosomal recessive gene inheritance pattern. Treatment: RBC transfusions, simple or exchange.

13 January 2022: Textbook Updates

We have posted updates of the following topics:

Adrenal gland & paraganglia > Adrenal cortical carcinoma > Sarcomatoid variant
by Maria Tretiakova, M.D., Ph.D.
Topic summary: Extremely rare malignant tumor of adrenal cortex with biphasic carcinomatous and sarcomatous morphology. Least common variant of adrenal cortical carcinoma (ACC), ~30 cases reported. Slightly more common in females; M:F = 1:1.3. Vast majority presented with localized pain (abdominal pain and distension, loin pain, flank pain, back pain) related to the mass effect. Sarcomatoid ACC has a dismal prognosis, worse than conventional ACC; despite aggressive treatment, overall median survival for sarcomatoid ACC is 7 months. Radical resection is treatment mainstay.

Bone & joints > Other chondrogenic tumors > Periosteal chondroma
by Nuha Shaker, M.D., M.S., Shadi Qasem, M.D., M.B.A.
Topic summary: Rare benign cartilaginous neoplasm that arises on the surface of cortical bone beneath periosteum. Well defined dome shaped lesion. Affects children and young adults, predominantly < 30 years of age. Occurs in small bones of the hands and long bones of the skeleton. A subset of periosteal chondromas harbor mutations in one of the IDH genes. Benign tumor with a reported recurrence rate of 3.6%. Surgical management in the form of intralesional, marginal or en bloc resection, is the mainstay of therapy.

Lymphoma & related disorders > Mature T/NK cell disorders > T follicular helper phenotype > Follicular peripheral T cell lymphoma (F-PTCL)
by Abdallah Flaifel, M.D., Nicholas Ward, M.D.
Topic summary: A rare subtype of nodal lymphomas of T follicular helper (Tfh) cell origin with a follicular or perifollicular growth pattern exhibiting strong and consistent expression of T follicular helper markers. F-PTCL shares with angioimmunoblastic T cell lymphoma (AITL) not only morphologic features but also similar clinical features, genetic landscape and molecular signatures, which may suggest a common pathophysiology. Rare; slightly M > F. Typically aggressive course with reported 50% mortality within 24 months of diagnosis. Distinction between F-PTCL and PTCL, NOS has currently no impact on clinical management.

Soft tissue > General > WHO classification
by Borislav A. Alexiev, M.D.
Topic summary: WHO classification of soft tissue tumors serves as a guide to clarify diagnoses among a multidisciplinary team composed of pathologists, radiologists and clinicians. Adipocytic tumors: new entities atypical spindle cell / pleomorphic lipomatous tumor and myxoid pleomorphic liposarcoma. Fibroblastic and myofibroblastic tumors: 3 new benign entities are considered in the new classification. So called fibrohistiocytic tumors: most relevant entity that has disappeared since 2013 is represented by the family of so called malignant fibrous histiocytoma (MFH).

Stains & CD markers > Actin, alpha smooth muscle type
by Kemal Kösemehmetoğlu, M.D., Gina Johnson, M.D.
Topic summary: Actin is a 43000 kDa ubiquitous protein found in all cells. Identifies pericytes, myoepithelial cells, smooth muscle cells and myofibroblasts in normal, reactive or neoplastic tissue. Also called smooth muscle actin, SMA; clone ASM1 / 1A4 or sm 1. Alpha actins are found in muscle tissues and required for contraction, whereas the beta and gamma actins function as components of the cytoskeleton in many cells. Controversial results on deficiency in intestinal pseudoobstruction. Myogenic differentiation (either only SMA or SMA+ desmin) in dedifferentiated liposarcoma significantly decreases 5 year disease free survival.

10 January 2022: Textbook Updates

We have posted updates of the following topics:

Adrenal gland & paraganglia > Adrenal cortical carcinoma > Oncocytic variant
by Maria Tretiakova, M.D., Ph.D.
Topic summary: Malignant epithelial tumor of adrenal cortical cells with predominantly oncocytic morphology. Tend to be lower stage, rarely invade adjacent organs and seem to represent more indolent variant of adrenal cortical carcinoma (ACC) with delayed recurrence and improved survival, despite a larger average size and aggressive morphologic appearance. Median age: 48 years, range: 1 – 83 years; no gender predilection. Pure oncocytic ACC has a better prognosis than conventional ACC. Radical resection is treatment mainstay; lymphadenectomy in 75% of cases.

Kidney tumor > Benign adult tumors > Well differentiated neuroendocrine tumor (carcinoid)
by Lin Cheng, M.D., Ph.D., Maria Tretiakova, M.D., Ph.D.
Topic summary: Well differentiated epithelial neoplasm arising from renal parenchyma and showing neuroendocrine differentiation. Rare tumor arising from renal parenchyma; associated with horseshoe kidney and mature teratoma of kidney. Median age = 59; M:F = 52.2%: 48.8% for all renal neuroendocrine neoplasms. Symptoms include abdominal / back / flank pain, hematuria, palpable mass. Unfavorable prognostic factors: Age: > 40 years; Size: > 4 cm; > 1 mitotic figure/10 high power fields (HPF). Treatment: nephrectomy with lymph node dissection.

Thyroid & parathyroid > Thyroiditis > Subacute thyroiditis
by Truong Phan Xuan Nguyen, M.D., Huy Gia Vuong, M.D., Ph.D.
Topic summary: Granulomatous inflammation of the thyroid gland with characteristic clinical and microscopic findings. Histopathologically, characterized by granulomatous inflammation composed of multinucleated giant cells, foamy and epithelioid histiocytes, neutrophils, lymphocytes and plasma cells. Mostly seen in middle aged women. Diagnosis mainly based on clinical findings (fever, malaise, fatigue, muscle aches, neck pain, thyroid gland tenderness, odynophagia). Self limited, with patients returning to a euthyroid state within a few months. Anti-inflammatory treatment is the key.

Transfusion medicine > Red blood cell antigens > Kidd system
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Antigenic; antibodies clinically significant. Most Kidd antigens are widely expressed in the donor population. Antibodies tend to decrease over time; may become undetectable by blood bank methodology. Can cause hemolytic reactions and hemolytic disease of the fetus and newborn. Antibodies formed tend to be IgG1 or IgG2, which are better at fixing complement; this causes intravascular hemolysis clinically. 2M urea testing can be used to distinguish Kidd positive versus Kidd null individuals; Kidd positive cells will lyse with a rapid influx of urea while Kidd null cells will remain intact.

Vulva, vagina & female urethra > Nontumor > Vulvovaginal cysts
by Morgan Hrones, M.D., Natalia Buza, M.D.
Topic summary: Benign cysts located within the vulva or vagina. Vulvovaginal cysts may be congenital or acquired. Congenitally derived vulvovaginal cysts may represent an embryological derivative, a result of an urological abnormality or ectopic tissue. Müllerian cyst: Comprises 30 – 44% of all vaginal cysts. Gartner duct cyst: most commonly identified vaginal cyst in children. May present as a painful swollen cystic lesion. Most diagnosed clinically by position and appearance. Bartholin duct cyst: complete excision or marsupialization with antibiotic administration if necessary.

6 January 2022: Textbook Updates

We have posted updates of the following topics:

Adrenal gland & paraganglia > Adrenal cortical carcinoma > Myxoid variant
by Maria Tretiakova, M.D., Ph.D.
Topic summary: Rare variant of malignant epithelial tumor of adrenal cortical cells with extracellular myxoid component. Compared with conventional adrenal cortical carcinoma (ACC), myxoid variant has slightly more aggressive clinical behavior and shorter overall survival on univariate and multivariate analyses. Mean age: 48; age range: 16 – 82. Overexpression of miR-483-3p, miR483-5p and miR-210 indicate poor prognosis and are associated with male sex, presence of necrosis, high Ki67 proliferation index, mitotic count and increased SF1 expression on IHC. Radical resection is treatment mainstay.

CNS tumor > Gliomas, glioneuronal tumors, and neuronal tumors > Diffuse astrocytic and oligodendroglial tumors > Gliosarcoma
by Irfan Yasin, M.B.B.S., Katherine Schwetye, M.D., Ph.D.
Topic summary: Rare, classic variant of glioblastoma (GBM), WHO grade 4. De novo: primary gliosarcoma (GS); secondary GS develops in previously resected or irradiated glioblastoma. Typically affects adults in the fourth to seventh decades of life. Similar genetic alterations (p53 mutations, p16 deletions and PTEN mutations) both in glial and sarcomatous components support monoclonal origin. Median overall survival with treatment (both primary and secondary gliosarcoma): 17.5 months. Treatment includes maximal surgical resection, followed by radiotherapy and chemotherapy.

Placenta > Nonneoplastic placental conditions and abnormalities > Noninfectious > Infarct
by Athena Chen, M.D.
Topic summary: Placental parenchymal lesion comprised of villi that have undergone ischemic necrosis due to focally reduced placental (maternal) blood flow. Increasing number / total percentage of parenchymal involvement and central (versus peripheral / marginal) location are adverse prognostic indicators. Occurs in pregnant women, often whose pregnancies are complicated by gestational hypertension / preeclampsia, intrauterine growth restriction, indicated or spontaneous preterm birth. Severe maternal vascular malperfusion is associated with a 10 – 25% recurrence risk. Specific therapies are not available; however, management / prevention includes optimization of maternal health.

Salivary glands > General > Anatomy & histology
by Theoni Haralabopoulos, M.D., Jonathan Clark, M.B.B.S., Ruta Gupta, M.D.
Topic summary: 3 paired major salivary glands: parotid, submandibular, sublingual. Functional unit of all salivary glands consists of acini and ducts. Developmental process begins when preacinar buds invaginate the adjacent mesenchyme, proliferating through cords, which eventually form clefts and produce extensive branching; end result is terminal bulbs, which form the secretory unit. Saliva has a crucial protective and digestive function within the upper aerodigestive cavity, providing mucosal lubrication and dental protection, facilitating taste, initiating enzymatic digestion of carbohydrates and contributing to oral immunity.

Stains & CD markers > FLI1
by Muhammad Raza, M.B.B.S., Nasir Ud Din, M.B.B.S.
Topic summary: FLI1 (Friend leukemia integration 1) gene is a proto-oncogene located on chromosome 11q24. Due to the increasing number of tumors found to express FLI1, more specific markers or molecular confirmation is necessary for the diagnosis of Ewing sarcoma. Crucial role in maintenance and differentiation of hematopoietic stem cells and angiogenesis. Diagnosis of benign and malignant vascular tumors (positive). Overexpression in astrocytoma = poor prognosis.

3 January 2022: Textbook Updates

We have posted updates of the following topics:

Bladder, ureter & renal pelvis > Urothelial carcinoma – invasive > Plasmacytoid
by Timothy Isaac Miller, M.D., M.A., Maria Tretiakova, M.D., Ph.D.
Topic summary: Aggressive variant of urothelial carcinoma (UC) characterized by single infiltrating cells with eccentrically placed nuclei and abundant eosinophilic cytoplasm similar to plasmacytes or resembling signet ring cells due to intracytoplasmic vacuoles. Uncommon histologic variant of UC (~1 – 3%) with plasmacytoid morphology. Epidemiology same as conventional urothelial carcinoma: typically older men (median of 58 – 68 years) with smoking history association. Overall uniformly poor prognosis. More likely to receive neoadjuvant chemotherapy compared with conventional UC because it is discovered at a higher stage.

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Miscellaneous > Idiopathic hypereosinophilic syndrome
by Alexander Reese, D.O., Ling Zhang, M.D., Lynh Nguyen, M.D.
Topic summary: Idiopathic hypereosinophilic syndrome is a disorder defined by peripheral blood eosinophilia (absolute eosinophil count ≥ 1.5 x 109/L) for at least 6 months with organ damage / dysfunction attributable to tissue hypereosinophilic infiltrate per biopsy and no discernible underlying etiology. Clinically, if treatment is necessary to minimize tissue / organ damage, the criteria of 6 months might not be enforced and an eosinophil count ≥ 1.5 x 109/L on 2 occasions for ≥ 1 month apart may be sufficient. Typically occurs in adults age 20 – 50 years. Slowly progressive clinical course with death occurring due to cardiac damage in some cases. As HES progresses, initial treatment is often systemic glucocorticoid therapy with second line treatments including imatinib, interferon alfa and hydroxyurea.

Bone marrow nonneoplastic > Benign changes > Megaloblastic anemia
by Swati Bhardwaj, M.B.B.S., M.D., Julie Feldstein, M.D.
Topic summary: Disorder of impaired DNA synthesis (with normal RNA synthesis) that manifests with the presence of megaloblasts in the bone marrow resulting in ineffective and abnormal erythropoiesis and macrocytes / macroovalocytes in the peripheral blood. Multitude of etiologies: most commonly vitamin B12 or folate deficiency. Insufficient data regarding incidence and prevalence. Treatment: supplementation of B12 and folate; when malabsorption is a cause, parenteral supplementation is needed.

Fallopian tubes & broad ligament > Broad ligament > Walthard cell nests
by Shabnam Zarei, M.D.
Topic summary: Nests, cysts or plaques of metaplastic transitional epithelium involving the serosal surface of fallopian tube. Benign incidental finding. Small 1 – 2 mm yellow-white nodules beneath the serosa of the fallopian tube and paratubal soft tissue. Suggested association between Walthard cell nests and Brenner tumors or mucinous tumors of the ovary (stronger association with the former, though unexplained). Walthard cell nests can be the origin for rare examples of Brenner tumors outside the ovarian parenchyma.

Ovary > Other nonneoplastic > Calcification
by Aurelia Busca, M.D., Ph.D., Carlos Parra-Herran, M.D.
Topic summary: Ovarian calcifications are commonly found in the context of a neoplasm (mature teratoma, mucinous cystadenoma, serous neoplasia, etc.) or as incidental findings in grossly normal ovaries. Calcifications are divided into psammomatous (psammoma bodies) and nonpsammomatous. In a study of 28 patients, the presence of large ovarian calcifications (> 5 mm) identified by imaging in otherwise normal ovaries remained stable and was not associated with ovarian neoplasms. Resection if symptomatic, rupture or suspicion for neoplastic process.

30 December 2021: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Recurrent genetic abnormalities > AML with biallelic mutation of CEBPA
by Jessica Corean, M.D., Kristin Karner, M.D.
Topic summary: Subtype of acute myeloid leukemia (AML) with recurrent genetic abnormality. CEBPA mutations must be biallelic, not just a single mutation, for diagnosis. Accounts for 4 – 9% of AML diagnoses in children and young adults. Favorable prognosis similar to AML with inv(16)(p13.1q22) or t(8;21)(q22;q22.1). Treated with similar induction and consolidation methods as other AMLs: 7+3 (cytarabine and anthracycline) and consolidation with cytarabine or azacitidine. May benefit from stem cell transplant (cannot use family member with CEBPA mutation if germline).

Esophagus > Carcinoma > Basaloid squamous cell carcinoma
by Jinping Lai, M.D., Ph.D.
Topic summary: Esophageal basaloid squamous cell carcinoma (BSCC) is a rare variant of SCC. Morphological differential diagnoses could include adenoid cystic carcinoma, neuroendocrine carcinoma (particularly small cell type), carcinosarcoma and epithelioid sarcoma. Epidemiology: generally older males. Very poor prognosis in some cases; even though more likely to be poorly differentiated at presentation, could have similar clinical features and survival outcomes when compared with SCC. Treatment: same as conventional SCC; often unresectable due to advanced stage.

Ovary > General > Anatomy & histology
by Doaa Atwi, M.D., Lewis A. Hassell, M.D.
Topic summary: Paired female reproductive glands located on each side of the uterus, adjacent to the lateral pelvic wall, posterior to the broad ligament and anterior to the rectum. Ovaries play an essential role in the fertility and cycling of reproductive activity in women, mainly by controlling the development of the dominant follicle and producing hormones (estrogen and progesterone). Primary ovarian insufficiency: a condition diagnosed in women less than 40 years of age and characterized by depletion or dysfunction of the ovarian follicles with subsequent impaired ovarian function. Tests that evaluate the ovarian function usually done in the context of primary or secondary amenorrhea or infertility problems.

Pancreas > Other tumors > Solid pseudopapillary neoplasm
by Pooja Navale, M.D., Omid Savari, M.D., Joseph F. Tomashefski, Jr., M.D., Monika Vyas, M.D.
Topic summary: Low malignant potential tumors with unclear cell of origin and pathogenesis. Presents in younger women, classically as solitary body / tail mass. Represents 1 – 2% of pancreatic neoplasms; F:M = 10:1 (accounts for 30% tumors in 5 cm, male gender, necrosis, cellular atypia, vascular invasion, perineural invasion and invasion into adjacent structures). Surgical resection is curative in > 95% of cases.

Small intestine & ampulla > Malabsorption > Celiac sprue
by Juwairiya Arshi, M.B.B.S., Aaron R. Huber, D.O.
Topic summary: Celiac sprue / celiac disease (gluten sensitive enteropathy) is an immune mediated inflammatory disease of the small intestine seen in genetically predisposed individuals and is caused by sensitivity to prolamins, like wheat (gliadin), Barley (hordein), rye (secalin) and oats (avenin). Partial or total atrophy of intestinal villi and hyperplasia of intestinal crypts with chronic inflammation in the lamina propria. Seroprevalence rate: 1.4% worldwide; M:F = 1:1.85. Excellent prognosis with gluten free diet. Treatment: Repletion of nutritional deficiencies; gluten (laminin) free diet.

27 December 2021: Textbook Updates

We have posted updates of the following topics:

Bone & joints > Other nonneoplastic > Hyperparathyroidism
by Rabia Ahmed, M.B.B.S., Saba Anjum, M.B.B.S., Nasir Ud Din, M.B.B.S.
Topic summary: Metabolic bone disease; manifestation of hyperparathyroidism. Radiologically osteolytic lesion. More common in persons older than 50 years of age; M:F = 1:3. Increased serum parathyroid hormone (PTH) concentrations detected by receptors on osteoblasts, which then release factors that stimulate osteoclast activity. Brown tumors regress when the cause of hyperparathyroidism is removed. Normalizing PTH level with drugs, dialysis, parathyroidectomy or kidney transplantation will often cause the tumor to regress or resolve.

Cervix > Premalignant / preinvasive lesions – cytology > LSIL (cyto)
by Lucy Jager, M.D., Bonnie Choy, M.D.
Topic summary: Changes in squamous cells associated with human papillomavirus (HPV) infection, encompassing mild dysplasia and cervical intraepithelial neoplasia (CIN) 1. Lesion of intermediate or superficial cells caused by low risk and high risk HPV; most are transient infections with little risk for oncogenesis. Accounts for ~2.5% of all Pap test results. ~60% regress spontaneously. Management: personalized risk based recommendations based on a patient’s risk of CIN 3+, as determined by a combination of current results and past history.

Skin melanocytic tumor > Blue nevi, dermal melanocytoses and associated neoplasms > Blue nevus / cellular blue nevus
by Ali M. Alani, M.D., Sabina Desar, M.D., Carlos A. Torres-Cabala, M.D.
Topic summary: Common blue nevus (BN) was first described in 1906; typical clinical presentation is that of a blue to black macule, papule or nodule on the head, distal extremities or buttock. Blue nevi are not uncommon; more frequent in females (F:M = 2:1) and adults < 40 years. May be due to arrested melanocytic migration or from specific stem cells within the dermis. Dermoscopy shows homogenous, structureless pigment pattern, with variety of colors (blue, white-blue, black, brown and polychromatic). Common and cellular blue nevus: excision.

Small intestine & ampulla > Inflammatory disorders > Crohn’s disease
by Alaaeddin Alrohaibani, M.D., Elias Makhoul, D.O., Mary Wong, M.D., M.B.A.
Topic summary: Idiopathic chronic inflammatory condition that may involve any part of the upper and lower gastrointestinal tract. Diagnostic criterion: segmental disease, transmural inflammation, noncaseating granulomas, deep fissuring ulcers, ileal involvement. Slightly more common in women (F:M = 1.3:1). Disease course and severity may vary but is usually chronic and intermittent. Multidisciplinary treatment approach is recommended, including medications, surgery, nutritional, psychosocial support and cancer screening.

Stains & CD markers > Synaptophysin
by Y. Albert Yeh, M.D., Ph.D.
Topic summary: A protein (38 kD), encoded by the SYP gene; is an integral membrane glycoprotein localized to presynaptic neurosecretory vesicles. Integral membrane protein of small synaptic vesicles in brain and endocrine cells. Common neuroendocrine biomarker and combined use of chromogranin A, INSM1 and CD56 for diagnosing neuroendocrine tumors and neuroendocrine carcinomas. Synaptophysin expression correlates with resistance to abiraterone and enzalutamide treatment in patients with castration resistance prostate cancer. Synaptophysin positive tumors associated with worse prognosis in extrahepatic cholangiocarcinoma.

23 December 2021: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Myelodysplastic syndromes (MDS) > MDS with multilineage dysplasia
by Shajo Kunnath-Velayudhan, M.B.B.S., M.M.S.T., Julia T. Geyer, M.D.
Topic summary: Myelodysplastic syndrome (MDS) with multilineage dysplasia is characterized by 1 or more cytopenias and dysplastic changes in 2 or more of the myeloid lineages (erythroid, granulocytic and megakaryocytic). Blast counts < 1% in the peripheral blood and < 5% in the bone marrow. Median age: 67 – 70 years (M = 70 – 74, F = 75 – 79). Median overall survival 36 months. Treatment includes transfusion, iron chelation, erythropoiesis stimulating factors, etc.

Skin nonmelanocytic tumor > Cysts > Dermoid cyst
by Aayushma Regmi, M.B.B.S., Jodi Speiser, M.D.
Topic summary: Benign cutaneous developmental anomaly; arises from the entrapment of ectodermal elements along the lines of embryonic closure. Most commonly on the lateral aspect of the upper eyelid. About 60% of cases discovered in children 5 years old or younger; no significant predominance for sex and race. Results from incomplete closure of the neural tube during the third to fifth week of fetal development. Overall prognosis good, especially when there is no intracranial or intraspinal extension. Complete surgical resection is the treatment of choice.

Skin nontumor > Lichenoid and interface reaction patterns > Chronic cutaneous lupus
by Maryam Aghighi, M.D., Kiran Motaparthi, M.D.
Topic summary: Lupus erythematosus is a multisystem autoimmune disease that involves the skin and internal organs. Most common sites for discoid lupus erythematous are face, scalp and conchal bowl. Occurs mostly in young women. In patients with defects in innate immunity and opsonization, UV radiation causes apoptosis; subsequent phagocytosis leads to recognition of self antigens and autoimmunity. Low mortality but significant impact on quality of life due to dysesthesia, pruritus, scarring alopecia and dyspigmentation. Treatment: antimalarials such as hydroxychloroquine, acitretin and topical steroids.

Skin nontumor > Vesiculobullous and acantholytic reaction patterns > Dermatitis herpetiformis
by Michael Occidental, M.D., Randie H. Kim, M.D., Ph.D.
Topic summary: Acquired autoimmune subepidermal blistering disease due to gluten exposure and characterized by neutrophilic microabscesses and IgA deposits in the dermal papillae. Anti tissue transglutaminase antibodies cross react with epidermal transglutaminase and leads to cutaneous deposits of IgA (J Exp Med 2002;195:747). Most commonly ages 20 – 40; mainly seen in Caucasians of Northern European descent. Strong association with HLA DQ2 and HLA DQ. Gluten free diet (GFD): first line treatment.

Soft tissue > Adipose tissue tumors > Lipoma and variants > Angiolipoma
by Laura Warmke, M.D., Jeanne Meis, M.D.
Topic summary: Benign, soft tissue tumor consisting of mature adipose tissue and clusters of thin walled vessels, often containing intraluminal fibrin thrombi. Relatively common in young adults; male predominance. Tender, often multiple subcutaneous nodules. Forearm, trunk and upper arm are common sites. Benign lesion with excellent prognosis. Treatment: simple surgical excision; liposuction may reduce tumor burden in familial multiple angiolipomatosis.

20 December 2021: Textbook Updates

We have posted updates of the following topics:

Lung > Other nonneoplastic disease > ARDS / DAD
by Akira Yoshikawa, M.D., Andrey Bychkov, M.D., Ph.D.
Topic summary: In 1994, acute respiratory distress syndrome (ARDS) was defined as the acute onset of hypoxemia with bilateral infiltrates on frontal chest radiograph, with no evidence of left atrial hypertension; definition revised in 2012 by the ARDS Task Force. Although diffuse alveolar damage (DAD) is the stereotypical morphology of ARDS, clinical syndrome of ARDS is not synonymous with the pathologic diagnosis of DAD. Septic shock and multiple organ dysfunction syndrome account for about 50% of deaths in patients with ARDS, while respiratory failure is responsible for 10 – 20% of deaths. Treatment: removal of the original insult; since no treatment drastically improves the respiratory failure of ARDS, respiratory and systemic supportive care is needed until the patient survives from ARDS.

Skin nonmelanocytic tumor > Benign (nonmelanotic) epidermal tumors or tumor-like lesions > Seborrheic keratosis
by Caroline I.M. Underwood, M.D., Elizabeth Boswell, M.D.
Topic summary: Common, benign keratinocyte proliferation of middle aged and elderly. Age > 50; incidence increases with age; M = F. Multiple somatic mutations; most common: FGFR3, PIK3CA and HRAS. Single or multiple papules or plaques with a stuck on appearance (well demarcated edges). Dermoscope: small keratin filled cysts, fissures, ridges, small vessels with perivascular halo. Prognostic factors: Leser-Trélat sign may indicate underlying malignancy. Treatment: not necessary; usually for cosmetics or patient preference.

Skin nontumor > Dermal perivascular and vasculopathic reaction patterns > Dermal hypersensitivity reaction
by Jiejun Wu, M.D., Ph.D., Maxwell A. Fung, M.D.
Topic summary: Nonspecific histologic reaction pattern that may be seen in multiple clinical conditions. Sparse to moderately dense superficial and mid perivascular and interstitial lymphocytic infiltrate with eosinophils. Most reported patients are adults but may occur at any age. For idiopathic cases, T cell hypersensitivity with overexpression of Th2 cytokines may be involved. Idiopathic cases have chronic course with potentially unsatisfactory responses to treatment. In cases with a clinically confirmed disorder, management is dictated by standard management for that disorder.

Skin nontumor > General > Common terms & patterns
by Carina Dehner, M.D., Ph.D., Louis P. Dehner, M.D.
Topic summary: This topic represents an overview of common terms and microscopic findings of the most frequently seen reaction patterns in dermatopathology including granulomatous dermatitis, infections, lichenoid dermatitis, panniculitides, perivascular dermatitis, psoriasiform dermatitis, sclerosing dermatitis, spongiotic dermatitis, vasculopathic / vasculitic dermatitis and vesiculobullous dermatitis.

Soft tissue > Vascular > Benign > Hemangioma
by Qurratulain Chundriger, M.B.B.S., Nasir Ud Din, M.B.B.S.
Topic summary: Benign tumor composed of circumscribed proliferation of predominantly small capillary sized blood vessels. Most cases arise in children, with equal gender distribution. Most common complications in superficial lesions include ulceration and permanent skin changes, like scarring. Recurrence if larger or deep lesions are incompletely excised or inadequately treated. Treatment aims at stopping the growth of lesion. Systemic and topical beta blockers, alone or in combination with steroids or surgery, may be useful depending on age, site and size of lesion.

16 December 2021: Textbook Updates

We have posted updates of the following topics:

Lung > Other interstitial pneumonitis / fibrosis > Cryptogenic organizing pneumonia
by Akira Yoshikawa, M.D., Andrey Bychkov, M.D., Ph.D., Sakda Sathirareuangchai, M.D.
Topic summary: Since 1901, organizing pneumonia (OP) has been described with the name bronchiolitis obliterans as an interstitial lung disease with granulation tissue plugs within alveolar ducts and small airways secondary to a variety of causes, including infection, fume exposure, drugs, collagen vascular disease, allergic reactions and obstruction. Cryptogenic organizing pneumonia is a relatively rare disease but often needs to be considered, since its clinical and radiological manifestations are often varied and nonspecific. Incidence 6 – 9 per 100,000; no sex predominance. Good prognosis but frequent relapse. Most with cryptogenic organizing pneumonia and secondary organizing pneumonia completely recover with oral corticosteroids.

Skin nonmelanocytic tumor > Adnexal tumors > Sweat gland derived (apocrine & eccrine glands) > Poroma
by Aayushma Regmi, M.B.B.S., Jodi Speiser, M.D.
Topic summary: Benign glandular adnexal tumor that usually originates from cells of the outer layer of the acrosyringium and terminal eccrine duct. Single, slow growing, asymptomatic, well circumscribed, smooth, skin colored to red, slightly scaly papule or nodule. Most commonly affects adults. Falls under the broad category of poroid neoplasms or acrospiromas. Prognosis is excellent; most cases do not show aggressive behavior. Simple excision with shave or electrosurgical destruction is curative.

Skin nonmelanocytic tumor > Adnexal tumors > Sweat gland derived (apocrine & eccrine glands) > Syringocystadenoma papilliferum
by Mahyar Khazaeli, M.D., Kiran Motaparthi, M.D.
Topic summary: Benign, hamartomatous, adnexal tumor. Originates from the apocrine or the eccrine sweat glands. 50% of cases present at birth or in early childhood. 75% of cases are reported in the head and neck region. Often observed in association with other benign adnexal neoplasms, such as nevus sebaceus (8 – 19% of patients), apocrine nevus, tubular apocrine adenoma, apocrine hidrocystoma, apocrine cystadenoma and clear cell syringoma. Diagnosis: skin biopsy. Treatment: surgical excision.

Skin nontumor > Dermal granulomatous and necrobiotic reaction patterns > Foreign body reaction
by Matthew Franklin, M.D., Stephen Somach, M.D.
Topic summary: Inflammatory response, most often granulomatous, to an exogenous or endogenous substance that is regarded as foreign material by the cutaneous immune system. Foreign material may be introduced intentionally (such as tattoos of cosmetic fillers) or accidentally (such as metals or minerals at sites of trauma). Given the myriad substances capable of inducing a foreign body reaction, the demographic spectrum of those affected spans all ages and geographic locations. Identification of foreign substance can be ascertained using ultrastructural analytic techniques such as energy dispersive Xray spectroscopy / analysis. Nonablative quality switched lasers may be used to obliterate unwanted tattoo ink; minocycline for silicone granulomas.

Soft tissue > Adipose tissue tumors > Lipoma and variants > Lipoma
by Salvatore Lorenzo Renne, M.D.
Topic summary: Benign tumor composed of mature adipocytes. Most common soft tissue tumor; mostly subcutaneous, < 5 cm; radiologically, grossly and microscopically same as normal fat. Most common mesenchymal tumor in adults; M = F (slightly more common in males). Pathophysiology: reactivated expression of HMGA2 protein. Recurrence < 5%; incomplete surgery, higher local recurrence. Treatment: simple excision.