Primary Carcinosarcoma of the Pancreas With CD10-Positive Sarcoma Component.

Carcinosarcomas of the pancreas are rare entities with a dismal prognosis. We report a rare case of pancreatic carcinosarcoma in a 49-year-old African American female who underwent a total abdominal hysterectomy with right salpingo-oophorectomy and exploration of the pancreatic mass. The surgery revealed a sclerotic mass in the body and tail of the pancreas that was surgically unresectable, and a pancreatic biopsy confirmed the pathology of pancreatic carcinosarcoma. Histologically, the lesion showed a high-grade spindle cell sarcoma and adjacent moderately differentiated adenocarcinoma. On immunohistochemical examination, the carcinomatous component was positive for epithelial markers, and the sarcomatous component was focally positive for SMA and desmin. In addition, the sarcomatous component showed diffuse immunoreactivity for CD10 with a surrounding myofibroblastic proliferation. Reports have associated expression of CD10 in pancreatic stellate cells with increased tumor aggressiveness. In this article, we report a case of pancreatic carcinosarcoma that shows sarcomatous CD10 immunoexpression with higher Ki67 labeling in the sarcoma than the carcinoma raising the question if the sarcomatous component could be potentiating the aggressiveness of the carcinomatous component.

EBV-positive post-transplant lymphoproliferative disorder presenting as primary diffuse large B-cell lymphoma of the central nervous system.

Primary central nervous system post-transplant lymphoproliferative disorder (PCNS-PTLD) is a rare complication with inferior survival outcomes in solid organ transplant patients. It represents approximately 7-15% of all PTLD patients. Because of the rarity of this disease, the diagnosis of PCNS-PTLD is often challenging, and the optimal therapy has not been established. We report a case of a renal transplant patient who initially presented with acute altered neurological function, an enhancing mass lesion of the brain on magnetic resonance imaging (MRI), and nonspecific reactive histopathological changes on brain biopsy. The lesion was self-limited and spontaneously resolved without medical treatment for PTLD. Six months later, surveillance MRI revealed recurrence of the brain lesion. The biopsy showed morphologic changes consistent with Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma. The patient responded well to reduction of immunosuppression and treatment with a single-agent regimen of rituximab. This is an unusual case of PCNS-PTLD with an initial presentation resembling a self-limited reactive lesion.