27 June 2024: Textbook Updates

We have posted updates of the following topics:

Bone marrow neoplastic > Bone marrow – plasma cell and lymphoid neoplasms > Acute leukemia of ambiguous lineage > Acute undifferentiated leukemia
by Giby V. George, M.B.B.S., W. Richard Burack, M.D., Ph.D.
Topic summary: Acute undifferentiated leukemia (AUL) is an acute leukemia that does not express any lineage specific (i.e., myeloid or lymphoid) markers but expresses hematopoietic stem cell markers. Essential diagnostic criteria include the presence of ≥ 20% blasts in bone marrow or blood, without immunophenotypic expression of lineage specific markers. It occurs more frequently in adults; incidence has decreased over time, owing to improved diagnostic techniques. Presentation is similar to other leukemias, including cytopenias. AUL generally has a worse prognosis with a median overall survival (OS) of only 9 months, which is significantly lower than that of acute lymphoblastic leukemia and acute myeloid leukemia.

Breast > Other carcinoma subtypes, not WHO classified > Cystic hypersecretory carcinoma
by Andrew P. Sciallis, M.D.
Topic summary: Cystic hypersecretory carcinoma (CHC) is a variant of ductal carcinoma in situ (DCIS) characterized by a variably cystic, intraductal proliferation of epithelial cells with secretory features and intraductal secretory material resembling thyroid colloid. Likely accounts for ≤ 1% of all cases of DCIS. CHC can be unifocal or multifocal and often arises in a spectrum of other cystic hypersecretory lesions. CHC can be completely asymptomatic but physical examination findings include a mass or nipple discharge. At this point in time, the behavior of CHC does not appear to differ significantly from other types of DCIS and thus prognosis is influenced by estrogen receptor (ER) biomarker status, nuclear grade and presence of comedo type necrosis.

Colon > Drug induced colitides > Secukinumab induced colitis
by Sam Amofa-Ho, M.D., David Hernandez Gonzalo, M.D.
Topic summary: Secukinumab is a novel human IgG1 monoclonal antibody administered via subcutaneous injection that antagonizes interleukin 17A (IL17A) and has been associated with new and exacerbated cases of inflammatory bowel disease (IBD) and other patterns of injury (i.e., lymphocytic colitis and vasculitis). Endoscopic and histologic findings are usually indistinguishable from idiopathic IBD. Relatively rare in clinical trials: 8 cases of new onset IBD among 5,773 patients in clinical trials (versus 0 of 1,844 patients who received placebo). GI symptoms: diarrhea (often bloody), abdominal pain, nausea, vomiting; systemic symptoms: fever, malaise, elevated inflammatory markers. Treatment: cessation of offending agent; usual IBD treatments if severe.

Salivary glands > Primary salivary gland neoplasms > Malignant > Acinic cell carcinoma
by Arash H. Lahoutiharahdashti, M.D., Rema A. Rao, M.D.
Topic summary: Malignant epithelial neoplasm of the salivary glands characterized by serous acinar cell differentiation (cytoplasmic zymogen granules) in at least some of the neoplastic cells. ~6 – 8% of all salivary gland neoplasms and 10 – 17% of primary salivary gland malignancies. Etiology: familial predisposition; previous radiation exposure. Typical clinical presentation is a slow growing mass; pain, fixation to surrounding tissues and cranial nerve VII dysfunction are uncommon. Definitive diagnosis most often established on a surgical excision specimen (e.g., parotidectomy). 5 year survival: 97%; may recur years or decades after initial diagnosis. Radiotherapy may be indicated for tumors that metastasize or cannot be completely excised.

Thyroid & parathyroid > Other common thyroid carcinomas > Differentiated high grade thyroid carcinoma / high grade differentiated thyroid carcinoma (HGDTC)
by Marc Pusztaszeri, M.D.
Topic summary: Malignant follicular cell derived thyroid neoplasm that retains the distinctive architectural and cytomorphological features of differentiated thyroid carcinoma (DTC) (including papillary thyroid carcinoma [PTC], follicular thyroid carcinoma [FTC] and oncocytic thyroid carcinoma [OTC]) except for the presence of ≥ 5 mitoses / 2 mm² or tumor necrosis. Uncommon and underrecognized tumor representing < 3% of all thyroid cancers. Typically presents as a large solitary mass that has grown over several months. Established adverse prognostic factors include larger tumor size, age over 45, extrathyroidal extension and distant metastasis. Standard clinical management includes total thyroidectomy with consideration of lateral neck dissection.

Featured Image

Contributed by: Giby V. George, M.B.B.S.
Diagnosis: Acute undifferentiated leukemia
Bone marrow trephine biopsy showing involvement by acute undifferentiated leukemia. The bone marrow is hypercellular with a diffuse immature mononuclear infiltrate (H&E, 20x lens objective).