23 September 2021: Textbook Updates

We have posted updates of the following topics:

Adrenal gland & paraganglia > Other tumors > Adenomatoid tumor
by Katherine A. Lehman, B.S., Debra L. Zynger, M.D.
Topic summary: Rare benign nonfunctioning tumor of the adrenal gland of mesothelial origin. Proliferation of gland-like or vascular-like spaces lined by attenuated to columnar mesothelial cells. Epidemiology: age range 30 – 50 years, with peak incidence ~40 years. Thought to arise via entrapment of primitive mesenchymal cells from the Müllerian tract within the adrenal gland versus embolized mesothelial cells. Typically asymptomatic and discovered incidentally. Surgical excision or core biopsy with subsequent histopathologic evaluation necessary for diagnosis. Favorable prognosis, with no reported cases of recurrence following excision. Treatment: complete surgical resection.

Kidney nontumor > Glomerular disease > Infectious glomerulonephritis > Bacterial infection related GN
by Zhengchun Lu, M.D., Ph.D., Vanderlene Liu Kung, M.D., Ph.D.
Topic summary: Most common bacterial infection related glomerulonephritides in countries with higher human development indices are IgA dominant infection related glomerulonephritis and infectious endocarditis associated glomerulonephritis. Most common infectious agent is Staphylococcus aureus. Immune reaction to bacterial proteins, including bacterial superantigens, such as staphylococcal enterotoxins, ultimately result in immune complex deposition in glomeruli, inflammation, complement activation and glomerular injury. Diabetes and advanced age portend a worse prognosis. Primary treatment is antibiotic therapy targeting underlying infection.

Kidney tumor > Benign adult tumors > Hemangioma
by Bitania Wondimu, M.D., Maria Tretiakova, M.D., Ph.D.
Topic summary: Benign vascular proliferation, rarely diagnosed in kidney (more common in skin or superficial soft tissue). M:F = 1.8:1. Often associated with end stage renal disease; can be associated with acquired cystic kidney disease, polycythemia or renal cell carcinoma. Typically asymptomatic but can present with hematuria or flank / abdominal pain. Difficult to distinguish radiographically from malignant lesions; biopsy or excision often needed for definitive diagnosis. Excellent prognosis with excision. May regress spontaneously.

Pancreas > Acinar cell lesions > Acinar cell carcinoma
by Claudio Luchini, M.D., Ph.D.
Topic summary: Malignant exocrine neoplasm of the pancreas composed of cells with morphological resemblance to acinar cells and with immunohistochemistry positive for acinar markers. M:F = 2.1:1; average age: 60 years. Pathophysiology: accumulation of genetic alteration, including chromosomal instability and frequent allelic copy number variation. The prognosis is poor, with an average survival time of about 19 months. Treatment: surgical resection if possible, gemcitabine based chemotherapy / radiofrequency ablation, molecularly based target therapy in the case of actionable alterations.

20 September 2021: Textbook Updates

We have posted updates of the following topics:

Bladder, ureter & renal pelvis > Other nonneoplastic > Prostatic type polyp
by Bonnie Choy, M.D.
Topic summary: Uncommon, nonneoplastic urothelial tract polyp comprised of prostatic glands and stroma. Polypoid or papillary lesion consists of nonneoplastic prostatic glandular epithelium with 2 distinct cell layers (luminal / secretory layer and basal layer) and corpora amylacea. Broad age range: 19 – 89 years. Most common in prostatic urethra, often in and around verumontanum. Diagnosis: cystoscopy with biopsy or transurethral resection. Low potential for recurrence. Simple resection is often curative.

Fallopian tubes & broad ligament > Broad ligament > Paratubal cysts
by Stephanie L. Skala, M.D.
Topic summary: Fluid filled cyst with ciliated lining adjacent to fallopian tube. Almost always benign, with rare reports of borderline tumor. Typically noted incidentally on intraoperative or gross examination (found in ~7 – 10% of women). Believed to originate from mesothelium or be remnant of Müllerian duct or Wolffian duct. Most cysts are small and asymptomatic (< 1 to 8 cm; rarely, 20+ cm). While not often diagnosed on imaging, paratubal cysts are unilocular and anechoic or hypoechoic on ultrasound. Rarely gives rise to serous borderline tumor or even more rarely malignancy. Surgical excision of the paratubal cyst represents definitive treatment for symptomatic patients.

Small intestine & ampulla > Congenital anomalies > Meckel diverticulum
by Yongchao Li, M.D., Ph.D., Lizhi Zhang, M.D.
Topic summary: Meckel diverticulum (MD) is a congenital disorder caused by incomplete obliteration of omphalomesenteric duct, which results in a true diverticulum, typically located in the ileum within 2 feet from the ileocecal valve. Most common congenital malformation of the GI tract, affecting 2 – 4% of the population. 16% of patients may be symptomatic; among symptomatic patients, M:F ≈ 3:1. Asymptomatic Meckel diverticulum is often incidentally diagnosed during laparoscopy or laparotomy. Treatment for symptomatic Meckel diverticulum is surgical resection.

Soft tissue > Adipose tissue tumors > Lipoma and variants > Spindle cell / pleomorphic lipoma
by Laura Warmke, M.D., Jeanne Meis, M.D.
Topic summary: Benign adipocytic tumors, currently regarded as morphologic variants of a single neoplasm. Spindle cell lipoma contains a varying mixture of mature adipocytes, bland spindle cells and ropy collagen fibers; pleomorphic lipoma also contains pleomorphic and multinucleated floret-like giant cells. Commonly affects middle aged to elderly men (45 – 70 years). Characterized by partial or whole chromosome 13 or 16 deletions. Demonstration of CD34 positivity and loss of RB1 helpful for diagnosis. Benign lesion, no risk of metastasis. Conservative surgical excision only.

Stains & CD markers > p53
by Till Braunschweig, M.D.
Topic summary: Tumor suppressor gene at 17p13, 53 kDa. Strong nuclear positivity or complete absence by immunohistochemistry has a strong correlation with the presence of a mutation. Women: almost 100% develop TP53 mutation associated cancer with a risk of 49% by the age of 30. Men: 79% develop TP53 mutation associated cancer with a risk of 21% by the age of 30. Interpretation: wildtype (normal) – scattered nuclear staining, mid epithelial (basal sparing). Poor outcome in p53 aberrant hematopoetic malignancies. Mostly missense or nonsense mutations, loss of function or splicing mutations uncommon.

16 September 2021: Textbook Updates

We have posted updates of the following topics:

Breast > Ductal carcinoma in situ > Paget disease
by Jasmine Vickery, M.D., Anna Biernacka, M.D., Ph.D.
Topic summary: Mammary Paget disease (MPD) is a proliferation of malignant glandular epithelial cells (in situ carcinoma) in the nipple areolar epidermis. Cutaneous manifestation is due to tumor cells involving the epidermis and disrupting intercellular junctions. Relatively uncommon; occurs in 1 – 4% of women and 1 – 2% of men with breast cancer. In symptomatic cases, the diagnosis is primarily clinical and confirmed by histologic examination. Prognosis largely depends on the presence, extent and characteristics of the underlying tumor. Extent of surgery is determined by the extent of underlying breast carcinoma. Patients with limited disease are candidates for breast conserving therapy with central lumpectomy and whole breast irradiation.

Bone marrow neoplastic > Bone marrow – plasma cell and lymphoid neoplasms > Plasma cell neoplasms > MGUS-IgM
by Shuchi Zinzuwadia, B.S., Shweta S. Zinzuwadia, B.S., Maryam F. Raouf, M.D., Rita Gupta, M.D., Ameet R. Kini, M.D., Ph.D.
Topic summary: IgM monoclonal gammopathy of undetermined significance (MGUS) is characterized by < 3 g/dL of monoclonal IgM protein, < 10% clonal. Bone marrow clonal lymphoplasmacytic cells or clonal plasma cells < 10% of cellular elements. Prevalence of MGUS is 2 – 3% of adults over 50 years. Diagnosis of IgM MGUS is based on the presence of a serum IgM monoclonal protein < 3 g/dL, fewer than 10% clonal lymphoplasmacytic or plasma cells in the bone marrow and lack of evidence of progression to lymphoplasmacytic lymphoma / Waldenström macroglobulinemia, IgM multiple myeloma or AL amyloidosis. Risk factors for progression are initial concentration of the monoclonal protein (≥ 1.5 g/dL) and abnormal serum free light chain ratio. Treatment is not recommended for asymptomatic patients with IgM MGU; “Wait and watch” approach is usually followed.

Bone & joints > Notochordal lesions > Chordoma
by Jesse Hart, D.O.
Topic summary: Malignant tumor with notochordal differentiation. Typically involves the clivus, sacrococcygeal bones or vertebrae. Most commonly arises in the 40 – 60 year old age group (may occur at any age). Most cases are sporadic but rare cases may be associated with benign notochordal tumor. Diagnosis is based on morphology, immunohistochemical findings and anatomic location of the tumor. Median survival is 7 years; 5 year overall and disease free survival are 61% and 71%; 10 year overall and disease free survival are 41% and 57%. Treatment: usually surgery followed by radiation or radiation alone in poor surgical candidates; poor response to chemotherapy.

CNS nontumor > Toxic and metabolic disorders > Hepatic encephalopathy
by Palgun Nisarga, M.D., Kymberly A. Gyure, M.D.
Topic summary: Spectrum of neurocognitive abnormalities occurring in patients with acute or chronic liver disease or portosystemic shunting. Elevated blood ammonia levels considered to play central role. Epidemiology: chronic alcoholism, acute drug poisoning, status post portosystemic bypass, hepatic failure patients. Acute hepatic encephalopathy: cerebral edema and increased intracranial pressure (cause of death). Prognosis based on percent of viable hepatic parenchyma in acute hepatic failure. Treatment of precipitating event; reduce blood. ammonia concentration using nonabsorbable disaccharides or antibiotics

Soft tissue > Uncertain differentiation > Synovial sarcoma
by Farres Obeidin, M.D., Borislav A. Alexiev, M.D.
Topic summary: Malignant soft tissue tumor of uncertain histogenesis with variable epithelial differentiation. Can occur in or around any tissue in the body. Accounts for 5 – 10% of all soft tissue sarcomas; median age: 35. Etiology: despite the name, the cells of origin are not synovial cells; histogenesis is still debated. Biopsy is required for definitive diagnosis. Radiotherapy and adjuvant chemotherapy have been evaluated in high risk situations (tumors > 5 cm or difficult to resect).

13 September 2021: Textbook Updates

We have posted updates of the following topics:

Eye > Conjunctiva > Epithelial tumors > Squamous papilloma-conjunctiva
by Pablo Zoroquiain, M.D.
Topic summary: Benign tumor characterized by an outgrowth of epithelial and stromal elements of the conjunctiva. Strong association with human papillomavirus (HPV 6 and 11). Approximately 1% of epibulbar cases in children and 11% in adults. Human papillomavirus 6 and 11 (low risk subtype) in nonlimbal papilloma. Diagnosis performed under ophthalmologic examination; slit lamp observation usually aids in the differential diagnosis. High recurrence rate: younger patients > older patients. Observation and follow up can be used, as some of these lesions regress. Medical treatment includes cryotherapy, CO2 laser, mitomycin C, cimetidine and interferon.

Informatics, digital & computational pathology > Digital imaging > Digital imaging fundamentals & standards
by Snehal S. Sonawane, M.B.B.S., M.D., Dariusz Borys, M.D.
Topic summary: Dynamic, image based environment that enables the acquisition, management and interpretation of pathology information generated from a digitized glass slide. Glass slides are converted into digital images with the aid of specialized scanning machines; slides can then be viewed, managed, shared and analyzed utilizing computer based technology. Facilitates flexibility and remote working. Applications include frozen section diagnosis in remote areas, primary diagnosis of pathology specimens in clinical use, assessment of immunohistochemistry and in situ hybridization. Limitations: expensive, unstable technology (possibility of network, software and hardware failure), difficult to define a standard for pathology images due to various imaging and nonimaging parameters.

Pancreas > Cystic and intraductal lesions > Intraductal papillary mucinous neoplasm
by Diana Agostini-Vulaj, D.O.
Topic summary: Intraductal papillary mucinous neoplasm (IPMN) is a grossly visible noninvasive mucinous epithelial neoplasm arising from main pancreatic duct or branch ducts, usually > 5 mm, composed of various cell types with various cytologic and architectural atypia. Rising incidence likely secondary to better characterization of this entity along with use of radiologic imaging studies. No well established factors; cigarette smoking implicated in one series. Clinically divided into main duct IPMN, branch duct IPMN and mixed IPMN. Without an invasive carcinoma, has > 90% 5 year survival; those associated with an invasive carcinoma carry a worse prognosis (about half die of the disease). Main duct IPMN: surgical resection indicated if main pancreatic duct > 10 mm, jaundice or presence of mural nodules.

Placenta > Nonneoplastic placental conditions and abnormalities > Noninfectious > Chorangiosis
by Anh Huynh, M.D., Drucilla J. Roberts, M.D.
Topic summary: Capillary hyperplasia in terminal villi due to chronic placental hypoperfusion or low grade tissue hypoxia.Higher incidence in maternal pathological conditions associated with hypoxemia. May be seen in pregnancies complicated by preeclampsia, diabetes mellitus, high altitudes, anemia, certain infections, multiple gestations, cardiovascular or respiratory disease, air pollution, obesity and tobacco smoking. Altshuler criteria: > 10 capillaries in at least 10 terminal villi in ≥ 10 noninfarcted areas in at least 3 low power fields of the placenta. Focal and diffuse chorangiosis have similar prognostic features.

9 September 2021: Textbook Updates

We have posted updates of the following topics:

Liver & intrahepatic bile ducts > Infectious nonviral > Echinococcal cyst
by Maryam Aghighi, M.D., Ladan Fazlollahi, M.D. M.P.H.
Topic summary: Cestode (tapeworm) infection widespread across the world. Echinococcus granulosus is the most common (classic hydatid cyst). Common cause of hepatic cysts worldwide, particularly in sheep and cattle in farming areas. 60 – 70% in liver; also brain, lung, other sites. Mucosal attachment of tapeworm to small intestine in definitive hosts, such as dogs. Often asymptomatic for years due to slow growth but hepatic and pulmonary symptoms are most common. Diagnosis usually made by ultrasound or CT scan supported by positive hydatid serology. Treatment: surgical resection; puncture, aspiration, infusion of protoscolicidal agent, reaspiration.

Ovary > Germ cell tumors > Dysgerminoma
by Sharon Song, M.D., M.S.
Topic summary: Malignant primitive germ cell tumor with no specific type of differentiation. Female counterpart to testicular seminoma. Constitutes 1 – 2% of all malignant ovarian tumors. Arises from primordial germ cells of the ovary. Present with abdominal pain or distention. On ultrasound, tends to appear as a highly vascularized, large, solid, lobulated adnexal mass with irregular internal echogenicity. Most tumors are stage I at diagnosis; recurrence rate is low. Radiosensitive but responds very well to cisplatin based chemotherapy, with overall survival > 90%.

Transfusion medicine > Red blood cell antigens > MNSU system
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Antibodies to M and N are generally clinically insignificant; antibodies to other antigens, such as S, s and U, are clinically significant. Antigen type: peptide. M and N are present on glycophorin A protein; S, s and U are present on glycophorin B protein. Antibodies to M can form naturally without exposure, with auto anti-M commonly encountered. African Americans have a deletion in the coding region of GYPB and can form antibodies against S, s and U (a high prevalence antigen). Transmission via exposure to MNS antigens secondary to pregnancy or transfusion. M, N, S and s are generally destroyed by enzyme treatment.

Transfusion medicine > Transfusion therapy > Plasma use
by Abdulaziz Al Mana, M.D. M.Sc., Crystal Yan, M.D. M.B.A., Yamac Akgun, M.D., YanYun Wu, M.D. Ph.D.
Topic summary: Plasma is the aqueous part of blood and contains albumin, coagulation factors including fibrinogen, immunoglobulins and other proteins. Plasma transfusions are generally indicated in coagulopathic patients with active bleeding; all units should contain coagulation factors, natural anticoagulants and ADAMTS13 at acceptable levels but lower levels of heat labile Factors V and VIII can result if freezing of fresh plasma is delayed. Transfusion reactions that are strongly associated with plasma transfusion include allergic / anaphylactic reactions, transfusion related acute lung injury (TRALI) and transfusion associated circulatory overload (TACO).

2 September 2021: 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 > Marginal zone-nodal
by Anamarija M. Perry, M.D.
Topic summary: Primary nodal mature B cell lymphoma derived from postgerminal center B cell. Patients present with localized or generalized peripheral lymphadenopathy. Rare, most commonly seen in adults; median age 50 – 60 years. Association with hepatitis C infection in some studies. Diagnosis based on biopsy of affected lymph node. Indolent lymphoma with 5 year overall survival of 60 – 70%. Treatment: watch and wait strategy in patients with low tumor burden and no clinical symptoms.

Oral cavity & oropharynx > Soft tissue tumors & proliferations > Pyogenic granuloma
by Molly Housley Smith, D.M.D.
Topic summary: Benign and often reactive vascular proliferation of the oral mucosa, most commonly found on the gingiva. Associated with poor oral hygiene, chronic trauma, pregnancy, medications. Large age range; most common in the second and third decades of life. Diagnosis made upon histopathological examination of the excisional specimen. Good prognosis with low recurrence rate (8.2%). Treatment: conservative excision, extending to periosteum, with subsequent histopathologic examination.

Placenta > Gestational trophoblastic disease > Molar pregnancies > Partial hydatidiform mole
by Aurelia Busca, M.D., Ph.D., Carlos Parra-Herran, M.D.
Topic summary: Gestational trophoblastic disease with abnormal chorionic villi (hydatidiform mole) characterized by a spectrum of villous populations ranging from normal to substantially enlarged, with irregular contours and mild, focal trophoblastic hyperplasia. Most result from fertilization of a normal egg by 2 spermatozoa (dispermic, 99%). Excess of paternal chromosomes promotes growth of the placental tissue. Risk of persistent gestational trophoblastic disease (usually invasive mole) is up to 5.6% for partial mole, lower than for complete mole (up to 20%). Treatment: evacuation and curettage, with follow up with serum hCG levels and contraception until levels are undetectable

Soft tissue > So called fibrohistiocytic > Giant cell tumor of soft tissue
by Carina Dehner, M.D., Ph.D., Louis P. Dehner, M.D.
Topic summary: Giant cell tumor of soft tissue (GCT-ST) is a tumor of low malignant potential that is considered the soft tissue analog of giant cell tumor of bone. Morphologically identical to giant cell tumor of bone but lacks mutations in the H3F3A gene. Rare benign neoplasm, exact incidence unknown; M = F. Mononuclear stromal cells have oval to spindle shaped nuclei with ill defined cytoplasm lacking significant atypia. Significant atypia will exclude this diagnosis, however, mitotic activity is commonly seen and may be brisk. Conservative surgical resection with negative margins is curative in the majority of cases.

Transfusion medicine > Red blood cell antigens > Duffy system
by Brian D. Adkins, M.D., Garrett S. Booth, M.D., M.S.
Topic summary: Duffy antigens are common in whites but uncommon in the black population. Antibodies can cause hemolysis and hemolytic disease of fetus and newborn (HDFN). Duffy acts a receptor for P. vivax and P. knowlessi. Individuals of African descent commonly have mutations in the GATA1 gene, which acts as a promoter for erythroid transcription of the Fyb gene; these individuals lack Fyb on red cells but express it on other tissues and therefore do not form Fyb antibodies. Exposure to Duffy antigens secondary to pregnancy or transfusion.

30 August 2021: Textbook Updates

We have posted updates of the following topics:

Autopsy & forensics > Types of injuries > Sharp force injuries
by Lorenzo Gitto, M.D., Ponni Arunkumar, M.D.
Topic summary: Injuries produced by sharp objects. Incised wounds are caused by sharp objects that contain a blade with at least 1 sharp edge (knives, razors, swords, etc.). Stab wounds are caused by a sharp pointed object that enters the body during a more or less perpendicular movement. Chop wounds are produced by various objects that are generally heavy, relatively blunt and with at least 1 sharp edge. Before manipulating the body, it is critical to take photographs of the body as it is received; medical interventions may alter the shape and size of the wound. Radiology studies can be helpful in sharp force traumas.

Ovary > Sex cord stromal tumors > Sertoli-Leydig cell tumor
by Natalia Buza, M.D.
Topic summary: Rare ovarian tumor composed of sex cord (Sertoli cells) and stromal (Leydig cells) elements, accounting for < 0.5% of all ovarian neoplasms. Most common in young patients with a mean age of 25 years. May occur sporadically or in patients with DICER1 syndrome. May be suspected clinically in a young patient presenting with a combination of virilization, elevated testosterone levels and ovarian / pelvic mass on imaging studies. Behavior correlates with tumor grade and histologic subtype. Conservative fertility sparing surgery (unilateral salpingo-oophorectomy) and staging procedure (with or without lymphadenectomy) is usually performed in young patients with stage I tumors.

Placenta > Gestational trophoblastic disease > Nonneoplastic lesions > Placental site nodule
by Rachelle Mendoza, M.D., Sonali Lanjewar, M.D., M.B.B.S., Raavi Gupta, M.D.
Topic summary: Placental site nodule (PSN) is a rare benign lesion of chorionic type intermediate trophoblast. Features favoring the diagnosis include its usually small size, circumscription, extensive hyalinization, degenerative appearance and mitotic inactivity. Thought to arise from a noninvoluted placental site from remote gestations in the uterus. 45 – 82% have a history of endometrial curettage or cesarean section before their most recent pregnancy. Due to small size and circumscription, the lesions are usually removed in their entirety by the surgical procedure that led to their discovery. No specific treatment or follow up is necessary.

Salivary glands > Primary salivary gland neoplasms > Benign > Myoepithelioma
by Xiaofeng Zhao, M.D., Ph.D., Shuanzeng (Sam) Wei, M.D., Ph.D.
Topic summary: Rare, benign tumor composed almost exclusively of myoepithelial cells. Epithelial component should be less than 5% (some consider even focal epithelial differentiation sufficient to label the tumor as pleomorphic adenoma). No sex predilection. Arising from neoplastic myoepithelial or basket cells found between the basement membrane and the basal plasma membrane of acinar cells. No distinctive clinical features. Diagnosis is made through biopsy of the lesion with histological confirmation. Low recurrence rate. Complete surgical excision with free margin recommended.

Stains & CD markers > DOG1
by Nick Baniak, M.D.
Topic summary: Discovered on GIST 1; primarily used in the diagnosis of gastrointestinal stromal tumor (GIST). Essential features: monoclonal (SP31, K9, DOG1.1) and polyclonal antibodies. Encoded by a locus at chromosome 11q13 and has 3 known splice variants. Biologic significance of increased DOG1 expression in tumors is not entirely known. Interpretation: membranous and cytoplasmic. Sensitive and specific marker for GIST; sensitivity has been observed to be in the range of ~87 – 97%. Uses include differentiating salivary gland carcinoma subtypes and characterizing sloughed cells in testicular biopsies for infertility.

26 August 2021: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Myelodysplastic syndromes (MDS) > MDS with ring sideroblasts
by Ritika Walia, M.D., M.B.B.S., Cecilia C.S. Yeung, M.D.
Topic summary: Myelodysplastic syndrome (MDS) characterized by morphological dysplasia with presence of ring sideroblasts (RS); may or may not have an SF3B1 mutation. 3 – 11% of all MDS cases; median age: 60 – 73 years. Mutations in the SF3B1 gene lead to altered splicing of mitochondrial iron transporter gene and other metabolic genes, which in turn leads to the ineffective erythropoiesis and formation of ring sideroblasts. 1 – 2% cases evolve into acute myeloid leukemia (AML). Treatment: recombinant erythropoietin (EPO) for anemia.

Breast > Lobular carcinoma > Classic
by Joshua J.X. Li, M.B.Ch.B., Gary M. Tse, M.B.B.S.
Topic summary: Invasive breast carcinoma with loss of cellular adhesion, characteristically arranged in discohesive or single file patterns. Shows 16q loss (CDH1 gene located at 16q22.1 encodes E-cadherin, integral in formation of adherens junction responsible for cell adhesion). Comprises about 10% of invasive breast carcinomas. Presents as vague findings including thickening, induration or poorly defined breast mass. Older age, larger tumor size and metastatic axillary lymph node involvement are independent risk factors for survival and recurrence. Mastectomy may be preferred over breast conservation due to risk of local recurrence.

Lymph nodes & spleen, nonlymphoma > Lymph nodes-inflammatory / reactive disorders > Kimura disease
by Aishwarya Ravindran, M.B.B.S., Julie Teruya-Feldstein, M.D.
Topic summary: Benign chronic inflammatory disorder of unknown etiology. Predominantly affects young Asian males. Peak incidence between ages 20 – 40 years. Th1 / Th2 cytokine imbalance has been postulated as an underlying pathogenesis. Morphologic diagnosis characterized by hyperplastic reactive follicles surrounded by eosinophilic infiltrates in a background of polymorphous inflammatory cells. Benign entity with an indolent course. Conservative management in asymptomatic cases; surgery followed by radiotherapy has been shown to result in longer period of remission.

Soft tissue > Fibroblastic / myofibroblastic > Fibrosarcoma > Low grade fibromyxoid sarcoma
by Raul S. Gonzalez, M.D., Jerad M. Gardner, M.D.
Topic summary: Low grade sarcoma with fibrous and myxoid areas, whorled growth pattern, low cellularity, bland fibroblastic cells and curvilinear or arcuate vessels. Bland sarcoma that can metastasize after years to decades. Usually occurs in young to middle aged adults. Slow growing, painless soft tissue mass (1 – 18 cm). Neither the presence of focal intermediate to high grade sarcoma nor histologic features affect prognosis; however, a dedifferentiated recurrence (anaplastic round cell morphology with numerous mitoses) portends short survival. Treatment: complete excision with wide margins; resection of pulmonary metastases (metastasectomy) may be considered.

23 August 2021: Textbook Updates

We have posted updates of the following topics:

Breast > Inflammatory > Idiopathic granulomatous mastitis
by Jonathan Marotti, M.D.
Topic summary: Idiopathic granulomatous mastitis (IGM) is a lobulocentric granulomatous inflammation and a diagnosis of exclusion (excluding other causes of granulomatous inflammation). Rare, benign inflammatory process affecting women of childbearing age. Frequent in postpartum and breastfeeding women. Mimics breast cancer, including inflammatory breast cancer. Diagnosis based on breast core biopsy or surgical excision with histologic examination. Self limiting in approximately 50% of patients. No standard treatment guidelines.

Breast > Other nonneoplastic > Transgender breast pathology
by Gabrielle M. Baker, M.D., Yu Jing Jan Heng, Ph.D.
Topic summary: Transgender individuals have a gender identity that differs from their assigned sex; the term includes gender nonbinary individuals who do not identify as exclusively male or female. Gender affirming surgery in the TM subgroup of transgender individuals includes top surgery (i.e. chest contouring surgery, mastectomy, reduction mammoplasty). Gender affirming testosterone therapy has an impact on breast histopathology, particularly when taken for at least 12 months. Breast parenchyma is typically without macroscopic abnormality. Full spectrum of benign and malignant histologic alterations seen in cisgender breast tissue may be seen in the transgender setting.

Larynx, hypopharynx & trachea > Benign tumors / nonneoplastic > Vocal cord polyp
by Kyriakos Chatzopoulos, M.D., Ph.D.
Topic summary: Common benign laryngeal lesion, also known as laryngeal nodule or singer’s nodule. Benign exophytic, pedunculated (polyp) or sessile (nodule) lesion of the vocal cord, frequently related to voice overuse or irritation, lined by unremarkable squamous epithelium or with mild reactive atypia, overlying an edematous, myxoid or hyalinized fibroblastic stroma with telangiectatic vessels. Patients of all ages; occurs even in pediatric population. Diagnosis based on combination of clinical presentation, laryngoscopy findings and biopsy interpretation. Nodule treatment: voice therapy, phonomicrosurgery or intralesional corticosteroid injection.

Ovary > Germ cell tumors > Teratoma-mature
by Shannon Mingo Welter, M.D., Mahmoud A. Khalifa, M.D., Ph.D.
Topic summary: Benign tumor of the ovary composed of mature tissue representing at least 2 embryonic layers (ectoderm, mesoderm or endoderm). Malignant transformation occurs rarely. In case of malignant transformation, prognosis is related to the type of malignancy. Most common ovarian tumor (20% of all ovarian tumors, 95% of all ovarian germ cell tumors). No known causative agents. Diagnosis: mainly by ultrasound. Treatment: cystectomy in young women to preserve fertility; salpingo-oophorectomy in older women.

Uterus > Smooth muscle tumors > Smooth muscle tumors of uncertain malignant potential
by Gulisa Turashvili, M.D., Ph.D.
Topic summary: Smooth muscle tumors of uncertain malignant potential (STUMPs) are smooth muscle tumors with morphologic features exceeding diagnostic criteria for leiomyoma (including subtypes) but insufficient for a diagnosis of leiomyosarcoma. Morphologically heterogeneous and diagnostically challenging, requiring generous sampling for microscopic examination. Usually occurs in women of reproductive age or postmenopausal women. Genomic heterogeneity similar to leiomyosarcoma (ranging from few chromosomal alterations to high chromosomal instability). Recurrence rates are 7 – 28%. Surveillance is warranted every 6 months for 5 years and then yearly.

19 August 2021: Textbook Updates

We have posted updates of the following topics:

Bone & joints > Osteogenic giant cell rich tumors > Giant cell tumor of bone
by Borislav A. Alexiev, M.D.
Topic summary: Giant cell tumor of bone (GCTB) is a locally aggressive and rarely metastasizing neoplasm composed of neoplastic mononuclear stromal cells admixed with macrophages and osteoclast-like giant cells. Osteolytic circumscribed tumor involving the epiphysis and metaphysis, generally in skeletally mature individual. GCTB related clonal aberrations occur in a background of epigenetic histone modifications (especially the G34W mutation of H3F3A gene). Pulmonary metastasis in ~2% of cases; they are very slow growing (nonaggressive) and may spontaneously regress; metastases have same morphology as the bone lesion. Preferential treatment is curettage and high speed drilling with local adjuvants.

Liver & intrahepatic bile ducts > Metabolic diseases > Hemochromatosis
by Nicole Leonard, M.D., Kimberley J. Evason, M.D., Ph.D.
Topic summary: Most common autosomal recessive disorder in Caucasians, caused by decreased hepcidin activity due to mutations in iron metabolism genes such as HFE, resulting in increased iron absorption, toxic iron accumulation and end organ damage. Diagnosis can be confirmed with HFE genetic testing but liver biopsy may still be necessary to assess fibrosis. Men typically develop symptoms at 40 – 60 years old; women typically develop symptoms after menopause. Life expectancy is normal if diagnosed and managed before end organ damage develops. Treatment: therapeutic phlebotomy / venesection.

Prostate gland & seminal vesicles > Inflammation > Abscess
by Andrii Puzyrenko, M.D., Ph.D., Kenneth A. Iczkowski, M.D.
Topic summary: Complication resulting from the acute infectious process of the prostate (prostatitis) characterized by a focal accumulation of purulent material within the prostate. Infection is caused mainly by gram negative rods. Incidence of prostatic abscess is 0.5% of all urologic diseases and 6% of all acute bacterial prostatitis; mortality rate is 1 – 16%. Most common way of developing is a reflux of infected urinary contents into prostatic ducts. Prognostic factors: depends on the timely diagnosis, treatment and underlying medical conditions. Medical treatment: broad spectrum parenteral antibiotics; surgical treatment: ultrasound guided aspiration.

Prostate gland & seminal vesicles > Other nonneoplastic lesions > Urethral polyp
by Y. Albert Yeh, M.D., Ph.D.
Topic summary: Uncommon, benign, polypoid or papillary growths protruding into the urethral lumen. Characterized by delicate papillae with true fibrovascular cores lined with prostatic epithelium with focal benign urothelial cells; prostatic acini are often present in the polyp. Occurs in adult men, age range 27 – 41 years, uncommon in younger men. Ectopic prostatic acinar epithelium presents focally in urothelial tract, commonly in posterior urethra, rarely in bladder neck and penile urethra. Excellent prognosis for prostatic type urethral polyp and fibroepithelial urethral polyp. Treatment: cystoscopic excision and fulguration.

Salivary glands > Cytology > Milan system > Milan system-overview
by Jen-Fan Hang, M.D.
Topic summary: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was developed by an international consortium of experts and endorsed by the American Society of Cytopathology (ASC) and the International Academy of Cytology (IAC). Main outputs useful for clinical decisions and lab quality control are risk of malignancy (ROM) and frequency of each diagnostic category. Consists of 6 diagnostic categories: nondiagnostic, nonneoplastic, atypia of undetermined significance (AUS), neoplasm (benign and salivary gland neoplasm of uncertain malignant potential [SUMP]), suspicious for malignancy (SM), malignant.