Bile duct adenomas in heterozygous (MZ) deficiency of alpha 1-protease inhibitor.

A case of bile duct adenomas in association with heterozygous (MZ) deficiency of alpha 1-proteinase inhibitor (API) is presented. The salient features were the presence of large API-containing globules in the adenomatous tissue and only minimally, in granular form, in hepatocytes. alpha 1-Proteinase inhibitor was not demonstrated in portal bile ducts entrapped in the adenomatous tissue or in bile ducts present in the liver parenchyma. Bile duct markers such as cytokeratin and carcinoembryonic antigens were present in the adenomatous tissue and also in the normal bile ducts, but not in the hepatocytes, suggesting that the adenomatous structures are ductular in origin, and probably not from ductular metaplasia of liver cells. Accumulation of API is postulated to be a triggering factor in neoplastic transformation.

T-cell morphology in nodular follicular center cell lymphomas.

T cells are known to be frequently numerous in follicular lymphomas but are generally considered to be a homogeneous population of small, round, "resting" lymphocytes. Although immunologic studies have suggested the presence of some "activated" T cells in these B-cell neoplasms, virtually no attention has been paid to the T-cell morphology. Wright-stained cytocentrifuged sheep erythrocyte (SRBC) rosette preparations from 20 cases of nodular follicular center cell lymphomas were therefore examined and the morphologic appearance of the SRBC rosetting cells was categorized. A mean of 19% (range 11-33%) of the SRBC-positive cells present were medium or large in size (diameter greater than two SRBCs, approximately 10 micron). A mean of 62% of SRBC-positive cells had round nuclei; 18% had indented nuclei and 20% had irregularly shaped nuclei. These data provide supportive morphologic evidence for some T-cell "activation" in certain follicular lymphomas. In addition to having possible functional and biologic implications, the previously undescribed presence of enlarged and sometimes "atypical" T cells in uncomplicated follicular lymphomas has implications for interpreting the histopathology of these B-cell neoplasms and the reported occurrence of composite T-cell/follicular center-cell lymphomas.