We have posted updates of the following topics:Lymphoma & related disorders > Mature B cell neoplasms > DLBCL and large B cell lymphomas with high grade features > DLBCL, NOS
by Matthew M. Klairmont, M.D., Christopher Y. Park, M.D., Ph.D.
Topic summary: Large B cell lymphoma with a diffuse growth pattern which does not meet the criteria for other WHO defined large B cell lymphoma categories. Medium to large atypical lymphoid cells. Median age = seventh decade but occurs across all ages. Unfavorable clinical prognostic features: ↑ age, ↑ LDH, Eastern Cooperative Oncology Group (ECOG) ≥ 2, Ann Arbor stage III / IV, extranodal disease, bulky disease. Treatment: R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone); other rituximab based regimens.
Skin nontumor > Dermal granulomatous and necrobiotic reaction patterns > Rheumatoid / rheumatic nodules
by Mahyar Khazaeli, M.D., Kiran Motaparthi, M.D.
Topic summary: Rheumatoid nodules are the most common extra-articular manifestation of rheumatoid arthritis (RA). Most common on pressure points (such as the olecranon process); however, they may occur at other sites, including within the lung and other internal organs. 30 – 40% of all patients with rheumatoid arthritis develop nodules. Multiple subcutaneous nodules, in the presence of rheumatoid factors and in the absence of any joint complaints, firmly suggest a diagnosis of rheumatoid nodulosis. Treatment of rheumatoid nodules is unnecessary because they are often asymptomatic.
Soft tissue > Fibroblastic / myofibroblastic > Calcifying aponeurotic fibroma
by Zoonish Ashfaq, M.B.B.S., Saba Anjum, M.B.B.S., Nasir Ud Din, M.B.B.S.
Topic summary: Rare tumor of children and adolescents, that involves the distal extremities, in association with aponeuroses, tendons and fascia. Infiltrative lesion composed of bland spindle cells within a collagenous matrix. Usually occurs in children < 15 years old. Presents as painless, poorly circumscribed soft tissue swelling of prolonged duration. Benign but locally aggressive; due to infiltrative nature, local recurrences may occur. Complete surgical excision is warranted.
Stains & CD markers > ERG
by Michael Michal, M.D., Ph.D.
Topic summary: Transcriptional regulator ERG is a protein encoded by ERG (ETS family transcription factor ERG), which is located at 21q22. Highly sensitive and quite specific immunohistochemical marker for vascular differentiation, including benign and malignant vascular tumors. Nuclear staining. EWSR1-ERG or FUS-ERG rearrangements are together present in about 5% of Ewing sarcomas. Currently one of the best available markers of endothelial differentiation, including vascular neoplasms, such as hemangioma, hemangioendothelioma, angiosarcoma and Kaposi sarcoma.
Thyroid & parathyroid > Benign thyroid neoplasms > Hyalinizing trabecular tumor
by Virginia A. LiVolsi, M.D.
Topic summary: Neoplasm of follicular cells showing a trabecular growth pattern of large cells with pale to eosinophilic cytoplasm containing stromal hyaline material; the nuclear features show elongation, grooves and intranuclear inclusions. GLIS translocation is unique to this thyroid tumor. Hyalinizing trabecular tumor (HTT) comprises fewer than 1% of thyroid neoplasms, shows a female preponderance > 80% and occurs in adults (mean age 50 years). Overwhelming majority of HTT are benign neoplasms; very rare examples showing capsular or vascular invasion have been reported. Surgery with removal of the affected thyroid lobe is curative.