Search

Signet ring cell lymphoma is an exceedingly rare subtype of non-Hodgkin lymphoma that was originally thought to be a morphologic variant of follicular lymphoma. To date, 56 cases have been reported, with the majority occurring in lymph nodes and bone marrow. Herein, we report a case of a 37-year-old female who presented with a left inguinal mass and high suspicion of lymphoma that was rendered on MRI. A successful ultrasound-guided core biopsy was performed. Pathologic examination revealed a diffuse large B-cell lymphoma (DLBCL) with unique signet ring histology and post-germinal center phenotype. In-situ hybridization showed an isolated BCL-6 gene rearrangement and confirmed the absence of a double-hit phenotype. This case would be situated as the second case of activated B-cell (ABC) signet ring lymphoma and the first case to arise in this anatomic location. The patient recently initiated therapy with a standard six-cycle regimen of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone).

Objectives: Monitoring of frozen section diagnostic performance provides an important quality improvement measure., Methods: Surgical specimens involving a frozen section diagnosis over a 3-year period were retrospectively reviewed. Glass slides were reviewed on cases with discordance. Discordance and deferral rates were calculated., Results: Of 3,675 frozen section diagnoses included, 96 (2.7%) were discordant with the final diagnosis. Additionally, 114 frozen section diagnoses (3.1%) were deferred. The organ-specific discordance rates were lowest in breast and genitourinary specimens and highest for pancreas, lymph node, and gynecologic specimens. Deferral rates were highest in musculoskeletal, breast, and hepatobiliary cases and lowest in thyroid, parathyroid, and neuropathology cases. Discordance was explained by block-sampling error (45%), specimen-sampling error (27%), or interpretation error (27%). Discordant frozen section diagnoses from gynecologic specimens were responsible for 81% of specimen-sampling errors; frozen section diagnoses of lymph nodes, head and neck, and pancreas were responsible for 54% of interpretation errors; 51% of block-sampling errors involved lymph node evaluation for metastatic carcinoma., Conclusions: Careful gross evaluation and microscopic examination of multiple levels should minimize specimen-sampling error and block-sampling error, respectively. Periodic review of accuracy and deferral rates may help reduce errors and improve the overall performance of this essential procedure., (© The Author(s) 2022. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)