Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma (MEITL) Presenting As An Obstructive Pancreaticoduodenal Mass: A Case Report. (28th October 2020) - Ritter, J P
Abstract: Casestudy : A 74-year-old woman of Scottish descent presented with obstructive jaundice and weight loss. Imaging revealed a head of pancreas mass with extrahepatic bile duct dilation. Fine needle aspiration cytology of the mass was non-diagnostic, therefore the patient underwent a pancreaticoduodenectomy. Gross examination revealed a circumferential, necrotic lesion involving the periampullary duodenum with invasion into the pancreas and peri-pancreatic soft tissue. Microscopically, the lesion was composed of diffuse sheets of monomorphic medium-sized cells with fine chromatin, inconspicuous nucleoli, and scant pale cytoplasm. The duodenal mucosa overlying the lesion was ulcerated. Epitheliotropism was noted in the duodenal villi, crypt epithelium and pancreatic duct epithelium. The tumor showed extensive areas of necrosis and conspicuous perineural invasion. The duodenal mucosa uninvolved by the tumor showed no evidence of an underlying enteropathy, such as Celiac disease. By immunohistochemistry, the neoplastic cells were positive for CD45, CD3, CD8, CD56, TIA-1, granzyme B, TCR-BF1, and TCR-gamma, and were negative pan B-cell markers, CD4, CD5, CD25, CD30, EBER, HHV-8, and TCL-1. Molecular studies for T cell clonality revealed clonal TCR-alpha-beta and gamma-delta gene rearrangements. Given the morphologic and immunophenotypic findings, the diagnosis of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) was rendered. This case is unique with features not typical of MEITL, namely mass-like pancreaticoduodenal presentation resulting in a Whipple resection, extensive necrosis, and perineural invasion.