16 May 2022: Textbook Updates

We have posted updates of the following topics:

Colon > Infectious colitis > Amebic colitis
by Blaine A. Mathison, B.S., Bobbi S. Pritt, M.D., M.Sc.
Topic summary: Disease caused by infection of the large intestine with the protozoan parasite, Entamoeba histolytica. Transmission primarily by ingestion of E. histolytica cysts in fecally contaminated food or water (fecal – oral); also by sexual contact (oral – anal). Occurs worldwide but more common in tropical and subtropical regions. Definitive diagnosis of amebic colitis is made by finding trophozoites that have invaded the intestinal mucosa. Amebic colitis is treated with both an amebicidal and luminal agent.

Colon > Diverticular disease > Diverticulosis
by Bindu Challa, M.D., Martha M. Yearsley, M.D.
Topic summary: Anatomic change in the colon characterized by outpouchings of mucosa and submucosa through the muscularis. Diverticulosis can be asymptomatic or symptomatic. Highest incidence in Western world; prevalence increases with age. Occurs in weaker portions of the colonic wall where vasa recta infiltrate the circular muscle layer. Frequently is an incidental finding during colonoscopy. Treatment: symptomatic uncomplicated diverticular disease (SUDD): dietary modifications to increase fiber, use of probiotics has been proposed; antibiotics in acute complicated diverticulitis.

Gallbladder & extrahepatic bile ducts > Extrahepatic bile duct tumors > Biliary intraepithelial neoplasia
by Satyapal Chahar, M.D., Monica T. Garcia-Buitrago, M.D.
Topic summary: Biliary intraepithelial neoplasia (BilIN) is a microscopic, premalignant, noninvasive neoplastic lesion of gallbladder or bile duct. Microscopically flat or micropapillary lesion with low or high grade dysplasia. Approximately 1 – 3.5% of cholecystectomies are found to have incidental BilIN; no gender predilection. Extensive disease, involvement of Rokitansky-Aschoff sinuses and positive margin status increase the risk of recurrence. Most high grade BilIN of gallbladder can be cured by cholecystectomy.

Stains & CD markers > IDH1 (R132H)
by Chunyu Cai, M.D., Ph.D.
Topic summary: Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are metabolic enzymes that catalyze the oxidative decarboxylation of isocitrate to produce α ketoglutarate (also known as 2 oxoglutarate [2OG]), NAPDH and CO2. IDH mutant gliomas have a better prognosis than the IDH wild type counterparts. IDH1 R132H immunostain is widely used in pathology laboratories on brain tumors in order to classify diffuse gliomas and provide prognostic implications. IDH1 (R132H) mutant gliomas show diffuse cytoplasmic reactivity in all tumor cells on IDH1 R132H immunostains.

12 May 2022: Textbook Updates

We have posted updates of the following topics:

Bone & joints > Other nonneoplastic > Epidermoid inclusion cyst
by Alnoor Akber, M.D., Nasir Ud Din, M.B.B.S.
Topic summary: Benign epithelial inclusion cyst in the bone lined with stratified squamous epithelium, identical to cutaneous counterpart. Post traumatic squamous epithelium embedded in bone. Rare incidence, young to middle aged. Common in the acral skeleton (fingers and toes) and skull. Asymptomatic / painless lump. Clinical, radiological and pathological correlation is adequate for diagnosis. Excellent prognosis. Treatment: simple curettage or excision.

Oral cavity & oropharynx > Other nonneoplastic > Amalgam tattoo
by Sarah H. Glass, D.D.S.
Topic summary: Iatrogenic implantation of exogenous foreign material, specifically dental amalgam, into the tissues of the oral cavity. Gray, blue or black macule on clinical exam in the oral cavity. Affects 3.3% of the U.S. adult population. Occurs in any location in the oral cavity, with gingiva and alveolar mucosa being the most common location due to proximity to the teeth. Excellent prognosis. No treatment is needed once diagnosis is established.

Skin nontumor > Dermal perivascular and vasculopathic reaction patterns > Erythema annulare centrifugum
by M. Suzanne Bloomquist, M.D., Silvija P. Gottesman, M.D.
Topic summary: Annular, erythematous, well circumscribed, mildly pruritic eruption with classic trailing scale (scale is seen behind the advancing erythematous edge). Clinicopathologic correlation is necessary, since the superficial variant may be indistinguishable from pityriasis rosea. Incidence: 1 per 100,000. One study showed that the superficial type may show shorter duration of skin lesion and better response to therapy but may have higher rate of recurrence. Typically, any treatment is directed at symptom relief, including topical corticosteroids and antihistamines for pruritic lesions.

Soft tissue > Adipose tissue tumors > Liposarcoma > Pleomorphic liposarcoma
by Stacy D. Webb, M.D., David Suster, M.D.
Topic summary: Pleomorphic, high grade sarcoma with variable numbers of pleomorphic lipoblasts, without areas that resemble atypical lipomatous tumor / well differentiated liposarcoma (or other lines of differentiation) and absence of MDM2 gene alterations by cytogenetic and molecular studies. M > F. 66% of cases occur on the extremities (lower limbs > upper). Aggressive, often exhibiting local recurrence and metastatic rates of 30 – 50%. Wide or radical resection with negative margins or amputation with postoperative radiotherapy; also chemotherapy.

Stains & CD markers > PAX5
by Austin Ellis, M.D., Ling Zhang, M.D.
Topic summary: 1 of 9 paired box transcription factors; involved in the differentiation and maturation of lymphoid progenitor cells into B cells, development of the nervous system and spermatogenesis. Nuclear marker expressed in most mature and immature B cell neoplasms. Activates B cell specific genes and represses genes specific for other hematopoietic lineages. Used to determine B cell lineage in lymphomas that lack CD20 expression. Expression may be associated with aggressive clinical course in olfactory neuroblastoma.

28 April 2022: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Other AML entities defined by the WHO > Acute panmyelosis with myelofibrosis
by Zarrin Hossein-Zadeh, M.D., Julie Feldstein, M.D.
Topic summary: Rare subtype of acute myeloid leukemia (AML), NOS. Acute panmyeloid proliferation with increased blasts (≥ 20% of cells in the bone marrow or peripheral blood) and fibrosis of the bone marrow. Mostly adults; very rare in pediatric population. Overall rapidly progressive clinical course, with a median survival of < 1 year. Treated as acute myeloid leukemia: 3+7 induction regimen with idarubicin and cytarabine, followed by high dose intermittent ARA C.

Cervix > Premalignant / preinvasive lesions – cytology > ASCUS (cyto)
by Joseph Reznicek, M.D., Bonnie Choy, M.D.
Topic summary: Atypical squamous cells of undetermined significance (ASCUS) refers to cellular changes that are suggestive but not diagnostic of low grade squamous intraepithelial lesion (LSIL). Criteria based on the 2014 Bethesda System for Reporting Cervical Cytology: nuclei are approximately 2.5 – 3.0x the area of the nucleus of a normal intermediate squamous cell. Accounts for 4.3% (median) of all Pap test results. Accounts for > 90% of ASC interpretations in most cytopathology laboratories (while atypical squamous cells cannot exclude a high grade squamous intraepithelial lesion [ASC-H] accounts for < 10%). HPV testing may be used as part of screening, triage and surveillance.

Colon > Neuroendocrine tumors > Mixed neuroendocrine nonneuroendocrine neoplasm
by Maria Kamal, M.D., Lewis A. Hassell, M.D.
Topic summary: Extremely rare and aggressive with a high grade neuroendocrine component (in the majority of cases). Mix of neuroendocrine and nonneuroendocrine components, each constituting at least 30% of the tumor; both components should be histologically and immunohistochemically proven. Age range of 32 – 96 years. Association with longstanding intestinal inflammatory disease. Prognosis of MiNEN is intermediate between that of pure adenocarcinoma and pure poorly differentiated neuroendocrine carcinoma. Surgery preferred for nearly all potentially curable cases. Chemotherapy and radiotherapy considered on case by case basis.

Uterus > Mixed epithelial and mesenchymal tumors > Atypical polypoid adenomyoma
by Stephanie L. Skala, M.D.
Topic summary: Polypoid lesion composed of atypical, architecturally complex endometrial glands within benign myomatous / fibromyomatous stroma. Stroma typically positive for SATB2, in contrast to most examples of myoinvasive carcinoma. Usually diagnosed in women of reproductive age; range of 25 – 73 years. Approximately 30 – 44% recur after conservative treatment; higher risk of recurrence if sampling is not under hysteroscopic visualization. Conservative management and close follow up can be considered for women that desire fertility preservation; addition of progestin does not seem to improve oncologic outcomes.

25 April 2022: Textbook Updates

We have posted updates of the following topics:

Breast > Fibroepithelial tumors > Hamartoma
by Indu Agarwal, M.D., Luis Blanco, Jr., M.D.
Topic summary: Well circumscribed, often encapsulated mass composed of normal but disorganized components of breast tissue. Presents as painless breast mass or detected by screening mammography or other breast imaging modalities. Found predominantly in women in the fifth decade but can be seen at any age. Often cannot be definitively diagnosed on core needle biopsy; excisional biopsy is more definitive. Rarely recurs; reported recurrences represent incomplete excisions. Surgical excision is curative but not necessary.

Coagulation > Hereditary bleeding disorders > Hereditary bleeding disorders – general
by Zaher K. Otrock, M.D.
Topic summary: Hereditary bleeding disorders are a diverse group of diseases that occur due to platelet dysfunction or absence / deficiency of specific clotting proteins, resulting in abnormalities of primary or secondary hemostasis. Primary hemostasis involves formation of a platelet plug which involves the endothelium, platelets and von Willebrand factor (vWF). Patients with primary hemostasis abnormalities are more likely to manifest mucocutaneous bleeding, while those with secondary hemostasis abnormalities tend to have muscle and joint bleeds. Bleeding in patients with hereditary platelet disorders is managed with platelet transfusions, antifibrinolytic agents, DDAVP (desmopressin) or recombinant factor VIIa, depending on the defect.

Microbiology & parasitology > Fungi > Dimorphic fungi > Blastomyces
by Smitha Mruthyunjayappa, M.D., Sixto M. Leal, Jr., M.D., Ph.D.
Topic summary: Taxonomy: class Eurotiomycetes, order Onygenales, family Ajellomycetaceae. Body temperature, uniformly sized, extracellular round yeasts with a thick, refractile, double contoured cell wall and broad based budding. Cause of blastomycosis, a chronic pyogranulomatous inflammatory disease. Soil organisms, associated with moist areas near riverbeds. Involves the lung in over 90% of cases. Acute pulmonary blastomycosis can be mild and self limited, not requiring treatment in immunocompetent hosts; more severe disease, particularly in immunocompromised hosts, requires itraconazole with or without liposomal amphotericin B.

Soft tissue > Adipose tissue tumors > Lipoma and variants > Chondroid lipoma
by Ummiya Tahir, M.B.B.S., Madiha Bilal Qureshi, M.B.B.S., Nasir Ud Din, M.B.B.S.
Topic summary: Benign adipose tissue tumor composed of lipoblasts intermixed with mature adipocytes in a myxohyaline chondroid matrix. Rare variant of lipoma with features of immature fat and immature cartilage. Primarily affects adult females. Age range: 20 – 40 years. Diagnosis requires presence of classic histologic features (i.e., presence of lipoblasts, chondroid cells and adipocytes in a myxohyaline matrix in a circumscribed lobulated tumor). Does not recur or metastasize if completely excised. Complete simple surgical resection is curative.

Stains & CD markers > INI1 / SMARCB1
by Felix K.F. Kommoss, M.D., Christian M. Schürch, M.D., Ph.D.
Topic summary: SMARCB1 (switch / sucrose non fermentable [SWI / SNF] related, matrix associated, actin dependent regulator of chromatin subfamily B member 1) is located on chromosome 22q11.2 and encodes a core subunit of the adenosine triphosphate (ATP) dependent SWI / SNF chromatin remodeling complex, which is actively involved in the regulation of gene expression. SMARCB1 is considered a bona fide tumor suppressor. Germline heterozygous pathogenic variants in SMARCB1 are associated with rhabdoid tumor predisposition syndrome 1 (RTPS1) and familial schwannomatosis.

21 April 2022: Textbook Updates

We have posted updates of the following topics:

Lymphoma & related disorders > Mature B cell neoplasms > Small B cell lymphomas with lymphoplasmacytic differentiation / marginal zone lymphomas > MALT-marginal zone
by Mario L. Marques-Piubelli, M.D., Roberto N. Miranda, M.D.
Topic summary: Extranodal, low grade B cell lymphoma that is composed of a heterogeneous population of centrocyte-like, monocytoid, scattered immunoblasts and centroblast-like cells. May occur in any extranodal bodily site with lymphoid follicle formation and is under the umbrella of marginal zone lymphoma (MZL), which also includes splenic MZL and nodal MZL. Median age: ~60 years; slight female predominance. Low (0), intermediate (1) and high (≥ 2) risk according to the presence of the following factors: advanced age (≥70 years), elevated LDH, Ann Arbor Stage III / IV. Watch and wait strategy may be considered, depending on the clinical setting; usually not recommended for nongastric MALT lymphomas.

Microbiology & parasitology > Gram negative bacteria > Shigella
by Nina J. Gao, Ph.D., Nicole E. Putnam, Ph.D.
Topic summary: Taxonomy: order Enterobacterales, family Enterobacteriaceae. Gram negative bacilli easily spread via fecal-oral transmission and highly infectious due to low infectious dose. Difficult to distinguish from E. coli due to high genomic and proteomic similarity. Risk groups: Children < 5 years of age in low / middle income countries, immunocompromised hosts, institutional environments. Nonspecific or suggestive diagnostic tests; recommend additional microbiologic work up. Rehydration is effective in shigellosis where stool volume is relatively low; antibiotic therapy in patients that are severely ill.

Pancreas > Congenital anomalies > Heterotopic pancreas
by Kenechukwu Ojukwu, M.D., M.P.P., Danielle Hutchings, M.D.
Topic summary: Pancreatic tissue that is anatomically separate from the main pancreatic gland and has no vascular or ductal connection to it. Composed of a variable mixture of pancreatic acini, ducts and islets. M:F = 3:1; most commonly identified in fifth to sixth decades of life. Can occur anywhere in the gastrointestinal tract. Often asymptomatic, frequently an incidental finding. Overall good prognosis but with potential to vary, depending on disease state of heterotopic tissue. Treatment: surgery, if symptomatic.

Soft tissue > Adipose tissue tumors > Liposarcoma > Myxoid pleomorphic liposarcoma
by Raul Perret, M.D., M.Sc.
Topic summary: Rare and aggressive variant of liposarcoma that predominantly affects young patients and shows hybrid morphological features of myxoid liposarcoma and pleomorphic liposarcoma. No clear gender predilection. Lesions are frequently large at initial diagnosis, probably due to the preference for mediastinal location and delayed development of symptoms. Aggressive soft tissue tumor with poor overall survival. Complete surgical excision with negative margins is the only potentially curative treatment; specific target therapies are currently unavailable.

Transfusion medicine > Stem cell transplant > ABO incompatible HSCT
by Tiffany Chambers, M.D., Mrigender Virk, M.D.
Topic summary: ABO blood group matching is not a barrier to successful hematopoietic stem cell transplantation (HSCT). ABO incompatible transplants are classified as major (recipient has isohemagglutinins directed against the donor red cells), minor (donor graft has isohemagglutinins directed against the recipient red cells) or bidirectional. ABO incompatible HSCT is possible because ABO blood group antigens are not expressed on pluripotent or early committed hematopoietic progenitor cells. Acute hemolysis classically presents with fever, flank pain and red urine; however, the presentation depends on the type of incompatibility and the volume infused. Acute hemolysis is treated with hydration and transfusion.

18 April 2022: Textbook Updates

We have posted updates of the following topics:

Lymphoma & related disorders > HHV8 associated lymphoproliferative disorders > HHV8 related DLBCL, NOS
by Annapurna Saksena, M.B.B.S, M.D., Elaine S. Jaffe, M.D.
Topic summary: Neoplasm characterized by a monoclonal proliferation of HHV8 infected lymphoid cells that resemble plasmablasts and express IgM lambda. Usually arises in association with multicentric Castleman disease (MCD) and HIV infection. Rare disease with overall frequency of 0.1%; median age is 47 years (range 39 – 66). Usually manifests with profound immunodeficiency, enlarging lymph nodes and massive splenomegaly. Extremely aggressive clinical course and poor prognosis. No definite treatment guidelines; can be treated with the same regimens described for patients with HIV associated DLBCL.

Transfusion medicine > Red blood cell antigens > Ii
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Ii antigens are carbohydrate antigens formed from multiple ABO moieties. Cold autoantibodies associated with infection; generally, not clinically significant. Antigens are formed by repeating lactosamines associated with ABH antigens on red cell surfaces. i is present in younger patients, with branching and complexity being added with age, leading to the presence of I antigens. Cold agglutinin disease is associated with antibodies that have high thermal amplitude and can react near body temperature.

Transfusion medicine > Red blood cell antigens > Lewis
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Lewis antigens are carbohydrates that are present in the plasma and adsorbed to the red cell surface. Created by enzymatic modification of type 1 chains. Lewis antigens are carbohydrates synthesized from type 1 chains with the fucosyltransferase FUT3. They modify chains with FUT3 to form Lea and H to form Leb. Exposure secondary to pregnancy or transfusion. Levels can decrease during pregnancy or with increased plasma volume and patient’s cells may phenotype as Lea-Leb-.

Transfusion medicine > Red blood cell antigens > P1PK GLOB
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Antibodies to P and PP1Pk are clinically significant. Autoanti-P antibodies are seen in paroxysmal cold hemoglobinuria and are associated with infection. P1, Pk and NOR are synthesized by enzymatic modification of glycolipids. P acts as a receptor for parvovirus B19. Individuals can develop autoanti-P with syphilis or upper respiratory infection: antibodies are IgG, bind at cold temperatures and cause complement mediated hemolysis upon warming. Antibodies are generally naturally forming in null individuals but sensitization can occur due to pregnancy or transfusion.

14 April 2022: Textbook Updates

We have posted updates of the following topics:

Bone & joints > Osteomyelitis > Bacterial osteomyelitis (acute)
by Hans Magne Hamnvåg, M.D., Dariusz Borys, M.D.
Topic summary: Infection involving bone, rare due to use of antibiotics; usually pyogenic. Bacteria proliferate in bone, cause inflammation and necrosis. Classified on the basis of duration of illness and mechanism of infection. Hematogenous osteomyelitis occurs most commonly in children, more than half in children younger than 5 years. Diagnosis is established via culture obtained from biopsy of the involved bone. Chronic osteomyelitis develops in a subset of acute osteomyelitis due to: delayed treatment, inadequate antibiotics, incomplete surgical debridement of necrotic bone and weakened host defenses. Treatment: antibiotic therapy, surgical debridement.

Oral cavity & oropharynx > Potentially malignant & dysplasia > Dysplasia
by Veronica Cheung, M.Ch.D., Ruta Gupta, M.D.
Topic summary: Abnormal proliferation of oral epithelial squamous cells showing cytologic and architectural atypia. Oral epithelial dysplasia describes a spectrum of changes in the oral squamous mucosa, as it transforms from normal epithelium into a premalignant lesion with potential to develop invasive carcinoma (if not adequately treated). Presentation can be variable, ranging from asymptomatic lesions to nonhealing ulcers. Persisting lifestyle factors (smoking / tobacco, excess alcohol, areca nut) increases risk of recurrence / progression. Surgical management is the treatment of choice.

Soft tissue > Uncertain differentiation > Alveolar soft part sarcoma
by Laura Warmke, M.D., Jeanne Meis, M.D.
Topic summary: Rare sarcoma of uncertain histogenesis. Malignant mesenchymal neoplasm frequently composed of large, polygonal cells with abundant eosinophilic cytoplasm, a nested or pseudoalveolar growth pattern and PASD+ intracytoplasmic rhomboid or rod shaped crystals. ASPSCR1-TFE3 translocation is an instigating genetic event. Accounts for < 1% of all soft tissue sarcomas. Patient age range is 1 – 78 years (median: 25 years). Commonly involves deep soft tissues of the extremities (61%, predominantly the lower extremity), trunk (20%), internal organs (8%) and head and neck (9%). ASPS is not formally graded but considered to be high grade; initial course may seem indolent but overall prognosis is poor.

Stains & CD markers > BCL6
by Elena M. Fenu, M.D., Danielle Lameirinhas Vieira Maracaja, M.D.
Topic summary: Transcription factor located at 3q27 that is required for germinal center B cell formation and follicular helper T cell (TFH) differentiation. Proto-oncogenic transcription factor that is involved in regulating B cell response to DNA damage. Marker of germinal center differentiation (also CD10). Coexpression of BCL6 and BCL2 by immunohistochemistry is abnormal and can help distinguish follicular lymphoma (85 – 90% in grade 1 – 2, < 50% in grade 3) from reactive follicular hyperplasia. Large cell lymphomas with rearrangements of MYC, BCL2 or BCL6 (double or triple hit lymphomas) are classified as high grade B cell lymphomas and carry a poor prognosis.

Stains & CD markers > CD3
by Leonie Frauenfeld, M.D., Christian M. Schürch, M.D., Ph.D.
Topic summary: Common antibody for identifying T cells. Member of immunoglobulin superfamily on 11q23; also called OKT3. CD3 is a cell surface complex composed of 4 distinct subunits; these subunits are chains of integral membrane glycoproteins that associate with T cell antigen receptor (TCR) and are required for TCR cell surface expression and signal transduction. Cytoplasmic positivity in immature T cells (cCD3), while negative surface CD3 (sCD3); complete and membranous positivity in mature T cells (CD3). Most specific T cell antibody, usually used to identify T cells in benign and malignant disorders; most antibodies are directed against epsilon chain.

7 April 2022: Textbook Updates

We have posted updates of the following topics:

Autopsy & forensics > General > Forensic toxicology
by Fabiola Righi, D.O., Lorenzo Gitto, M.D.
Topic summary: Forensic toxicology is the science that deals with the harmful effect of chemicals on the human body and the use of toxicology for the purpose of law. Toxicology results should be interpreted in the context of a thorough medicolegal investigation. Postmortem redistribution: redistribution of drugs into the blood from adjacent solid organs with high drug concentrations, such as lungs, liver and myocardium, affecting the interpretation of substance concentration in the blood after death. Quality and quantity of the sample determine the reliability of the toxicological analysis.

Breast > Breast stains > Ki67 breast
by Anas Mohamed, M.D., Joseph Geradts, M.D.
Topic summary: Nuclear protein that is expressed during all active phases of the cell cycle (G1, S, G2 and M) but is absent in resting cells (G0). Encoded by MKI67 gene on chromosome 10q25. Cellular proliferation marker that is reported as percentage of tumor cells with nuclear staining. Anti-Ki67 antibody binds Ki67 protein in formalin fixed paraffin embedded tissue block and highlights nuclei of all cells in nonresting cell cycle phases. Used as an independent prognostic marker to predict disease free survival, overall survival and complete pathologic response to neoadjuvant chemotherapy.

Chemistry, toxicology & urinalysis > Organ specific > Adrenal > Adrenal insufficiency-diagnosis
by Sarrah Lahorewala, B.D.S., Ph.D., Roger L. Bertholf, Ph.D.
Topic summary: Deficiency in the production of glucocorticoids (e.g., cortisol) due to a disorder of the adrenal gland (primary adrenal insufficiency), inadequate pituitary adrenocorticotrophin hormone (ACTH; secondary adrenal insufficiency) or suppression of ACTH due to decreased corticotrophin releasing hormone (CRH; tertiary adrenal insufficiency). Clinical presentation of adrenal insufficiency is nonspecific; therefore, diagnosis is confirmed via laboratory testing. Low basal cortisol levels are indicative of insufficiency; abnormal response on the ACTH stimulation test is confirmatory.

Lymphoma & related disorders > Mature B cell neoplasms > DLBCL and large B cell lymphomas with high grade features > Burkitt-like lymphoma with 11q aberration
by Anna Shestakova, M.D., Ph.D., Anamarija M. Perry, M.D.
Topic summary: Rare B cell lymphoma that resembles Burkitt lymphoma morphologically, phenotypically and by gene expression profiling. Features overlapping with Burkitt lymphoma but lacks MYC rearrangement. Most common in children and young adults, median in third decade; male predominance. Overall good prognosis, comparable to Burkitt lymphoma; 5 year overall survival of 80%. Treatment: intense chemoimmunotherapy with central nervous system prophylaxis.

Skin nontumor > Infectious disorders > Leishmaniasis
by Gerardo Cazzato, M.D., Giuseppe Ingravallo, M.D., Ph.D.
Topic summary: Protozoal disease caused by over more than 20 Leishmania species, in both tropical and subtropical regions. In H&E, presence of small hematoxylinophilic formations that are round, uniform in appearance, intracytoplasmic and sometimes distributed around the outer rim of the vacuoles (the marquee sign). Cutaneous form is predominantly in the Middle East, whereas the mucocutaneous form occurs in South America (Brazil, Bolivia, Peru). Treatment: organic salts of pentavalent antimony, antimoniate of N methylglucamine and sodium stibogluconate.

4 April 2022: Textbook Updates

We have posted updates of the following topics:

Bladder, ureter & renal pelvis > Squamous cell neoplasms > Squamous cell papilloma
by Harsh Batra, M.B.B.S., D.C.P., D.N.B., Anil Parwani, M.D., Ph.D., M.B.A.
Topic summary: Rare, benign tumor of the urinary bladder showing delicate fibrovascular cores lined by squamous epithelium. Presents with gross hematuria and irritative bladder symptoms. F > M (6:1); fourth to seventh decade. Most cases involve the dome and the lateral and posterior walls of the bladder. Etiology: smoking, occupational exposure to amines. Recurrence is very rare and progression to carcinoma has not been reported. Treatment: transurethral resection of bladder tumor (TURBT).

Colon > Inflammatory bowel disease > Crohn’s disease
by Luisa Ricaurte Archila, M.D., Catherine E. Hagen, M.D.
Topic summary: Chronic, relapsing, idiopathic inflammatory gastrointestinal disease. Segmental, patchy inflammatory bowel disease, often involving the ileum, colon and upper GI tract. Slight female predominance in adult onset Crohn’s disease. Diagnosis consists of a combination of clinical findings and complementary diagnostic tests including blood tests, stool tests, upper and lower endoscopic studies, radiologic imaging and histologic evaluation. Mainstay of treatment is medical therapy with a goal to achieve clinical, endoscopic and histologic remission, demonstrated by complete mucosal healing.

Molecular markers > BCR-ABL1
by Yi Ding, M.D., Ph.D.
Topic summary: Philadelphia chromosome (Ph) results from a reciprocal translocation between chromosomes 9 and 22[t(9;22)] that gives rise to a BCR-ABL1 fusion gene. Observed in 90 – 95% of patients with chronic myeloid leukemia (CML), up to 20 – 30% of adults with acute lymphoblastic leukemia (B-ALL), 5% of children with B-ALL and up to 1 – 2% of patients with acute myeloid leukemia (AML). If left untreated, the median survival rate of CML is around 2 – 3 years. Several tyrosine kinase inhibitors (TKIs) are approved as first line treatment for chronic phase CML, which has significantly improved the prognosis with up to 70% of people having a complete cytogenetic response 1 year after starting a TKI.

Pancreas > Other tumors > Mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs)
by Jennifer Ziebell, M.D., Ashwini Kumar Esnakula, M.D., M.S.
Topic summary: Pancreatic mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs) are rare and heterogeneous malignancies characterized by histologically recognizable neuroendocrine (i.e., carcinoma and rarely, a well differentiated neuroendocrine tumor) and exocrine (usually ductal carcinoma, acinar carcinoma or both) components, each composing ≥ 30% of the neoplasm volume. Exocrine component can either be pancreatic ductal adenocarcinoma (PDAC) or acinar cell carcinoma (ACC); very rarely, both acinar and ductal carcinoma. Average age at presentation is 68 years (ranges from 21 – 84 years). Tumor size and resectability are the most important prognostic factors. No clear treatment guidelines due to rarity of tumors.

31 March 2022: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Other AML entities defined by the WHO > AML with myelodysplasia related changes
by Srishti Gupta, M.B.B.S., M.D., Elizabeth Courville, M.D.
Topic summary: ≥ 20% myeloid blasts in the blood or bone marrow with 1 or more of the following: features of myelodysplasia, prior history of myelodysplastic syndrome (MDS) or MDS / myeloproliferative neoplasm (MPN) or MDS related cytogenetic abnormalities. Commonly presents with severe pancytopenia. Generally poorer prognosis with lower remission rates and shorter overall survival than other AML subtypes. Diagnosis of AML-MRC solely based on multilineage dysplasia or previously untreated MDS or MDS / MPN have significantly better outcomes than those with MDS defining cytogenetic abnormalities or disease secondary to a previously treated MDS or MDS / MPN.

Eye > Conjunctiva > Epithelial tumors > Conjunctival intraepithelial neoplasia
by Nfn/Fnu Kiran, M.D., Pia Mendoza, M.D.
Topic summary: Spectrum of abnormal growth of atypical squamous epithelial cells of the conjunctiva; graded based on thickness of epithelial involvement. Estimated incidence is 17 – 20 cases per 1 million person years. Incidence rate varies worldwide; highest rates in Africa (3.4 cases per 100,000 per year in Zimbabwe). Appears to be multifactorial, involving a variety of environmental factors in a susceptible host. Recurrence associated with higher grade lesions, tumors, advanced American Joint Committee on Cancer (AJCC) T category and positive margins. Treatment: surgical excision using a no touch technique with 2 – 4 mm margins, alcohol application and supplemental surgical margin cryotherapy.

Kidney tumor > Benign adult tumors > Juxtaglomerular cell tumor
by Alcino Pires Gama, M.D., Bonnie Choy, M.D.
Topic summary: Rare renin secreting tumor arising from the specialized smooth muscle cells of the glomerular afferent arteriole in the renal juxtaglomerular apparatus. Frequently associated with severe and poorly controlled hypertension, hypokalemia and hyperaldosteronism secondary to tumor renin secretion. Seen in young adults (20 – 35 years) but has been reported in children and older adults. 90% of patients will become normotensive following tumor resection. 10% remain mildly hypertensive despite surgical resection. Treatment: surgical resection – partial or total nephrectomy.

Pancreas > General > Papanicolaou system
by Victoria Jones, M.S., Derek Allison, M.D.
Topic summary: Internationally adopted recommendations for sampling, diagnosing and managing pancreaticobiliary cytology lesions. 6 tiered categorical system resulting in overall improved sensitivity / specificity and risk stratification. Primary method for sampling solid mass and cysts: endoscopic ultrasound fine needle aspiration (EUS FNA). Primary method for sampling strictures: endoscopic retrograde cholangiopancreatography (ERCP) guided brush cytology. Risk of malignancy (ROM) = total number FNA specimens that proved malignant on follow up / total number of surgical resections and clinical follow ups.

Testis & paratestis > Sex cord stromal tumors > Large cell calcifying Sertoli cell tumor
by Stephanie Siegmund, M.D., Ph.D., William Anderson, M.D., Andres Acosta, M.D.
Topic summary: Large cell calcifying Sertoli cell tumor (LCCSCT) was first described by Lange et al. in 1960. Generally presents as a benign sex cord stromal tumor found predominantly in patients < 20 years old; a subset presents in older patients and may behave aggressively. 20 – 40% of cases associated with Carney complex due to mutations in PRKAR1A gene. Kratzer et al. proposed malignant prognostic features that include age > 25 years old and 2 or more of the following adverse features: size > 4 cm, extratesticular extension, mitotic index > 3/10 high power fields (HPFs), coagulative tumor necrosis, vascular invasion, high grade cytologic atypia. Treatment: partial or radical orchiectomy for organ confined disease.