Primary Sarcomatoid (Spindle-Cell) Diffuse Large B-Cell Lymphoma of the Uterine Cervix in a Young Adult: A Case Report.

Primary diffuse large B-cell lymphoma (DLBCL) of the uterine cervix is an exceptionally rare extranodal malignancy. A sarcomatoid (spindle-cell) pattern of diffuse large B-cell lymphoma (DLBCL) is even more unusual and closely mimics mesenchymal or sarcomatoid epithelial tumors. We report a young woman with long-standing pelvic pain and abnormal bleeding whose cervix appeared friable and retracted, prompting biopsy. Histology showed DLBCL with sarcomatoid morphology. FISH demonstrated copy-number gains of MYC (56%) and IgH (59%) without rearrangements. PET-CT revealed an intensely FDG-avid cervical mass and a moderately avid right inferior thyroid nodule; fine-needle aspiration of the thyroid nodule was suspicious for follicular neoplasm (Bethesda IV). She began chemotherapy. This case highlights the diagnostic pitfalls of spindle morphology in cervical masses, underscores the importance of tissue confirmation of PET incidentalomas to avoid overstaging, and illustrates organ-preserving therapy in a young adult.