Carcinoma in jejunal pancreatic heterotopia.

BACKGROUND: Although heterotopic pancreas in the gastrointestinal tract is not uncommon, jejunal pancreatic heterotopia is a rare finding, and malignant transformation in such a location is very unusual. METHODS: We encountered a case of jejunal carcinoma in pancreatic heterotopia and because of its rarity, we reviewed the Armed Forces Institute of Pathology experience as well as the literature. The clinical, histopathologic, and immunohistochemical features were studied. RESULTS: In 109 patients diagnosed as having pancreatic heterotopia in the gastrointestinal tract between 1970 and 1997 at the Armed Forces Institute of Pathology, 67 cases (62%) occurred in the stomach, 42 (38%) in the small intestine, and none in the large intestine. We found 2 patients with adenocarcinoma arising in pancreatic heterotopia. The 2 cases arose in the jejunum. One was of the ductal type, while the other was an acinar cell carcinoma with focal ductular differentiation. In both cases the nontumoral pancreatic tissue contained ducts, acini, and islets. Review of the literature yielded 26 reports of 28 cases of carcinoma arising in heterotopic pancreas; of these, 18 were well documented. Only 1 occurred in the jejunum, and none was of the acinar type. CONCLUSIONS: Carcinoma in pancreatic heterotopia is rare, and acinar cell carcinoma in pancreatic heterotopia is extremely rare. Recognition of carcinoma in pancreatic heterotopia is important to prevent its misinterpretation as a metastatic tumor.

Carcinoid tumors of the ampulla of Vater: a comparison with duodenal carcinoid tumors.

BACKGROUND: Although ampullary carcinoid tumors (ACs) are often categorized clinically as duodenal carcinoid tumors (DCs), there are distinct clinical and pathologic differences. METHODS: Clinical, histopathologic, and immunohistochemical features of 12 ACs were compared with those of 53 DCs that did not involve the ampulla. RESULTS: Patients with AC were ages 28-74 years (mean, 54.9 years); 8 were males and 4 were females. Five were white and three were black; the race of four patients was not known. The size of ACs ranged from 0.2 to 5.0 cm in greatest dimension. There were no significant differences between AC patients and DC patients with respect to male predominance, race, tumor size, and mitotic rate. The insular growth pattern was more common in AC; the cribriform type was more common in DC. Four of 12 ACs contained psammoma bodies, versus none of 53 DCs (P = 0.001). The rate of metastasis was similar in patients with AC (4 of 12, 33%) compared with DC patients (14 of 53, 26%). In DC patients, involvement of the muscularis propria, a size greater than 2 cm, and mitotic activity were significantly correlated with metastatic risk. In AC patients, tumor size and mitotic activity had no correlation with metastatic potential. One AC had features of an atypical carcinoid tumor; there were none in the duodenal group. One-half of patients with AC presented with jaundice versus 7% of patients with DC (P = 0.005). Three patients (25%) with AC had von Recklinghausen disease versus 0 of 53 patients with DC (P = 0.003). Immunohistochemically, tumor cells expressed somatostatin in 67%, serotonin and cholecystokinin in 17%, insulin in 25%, and glucagon and gastrin in 0% of ACs. In contrast, 56% of DCs expressed gastrin (P < 0.001). CONCLUSIONS: Carcinoid tumors of the ampulla differ clinically, histologically, and immunohistochemically from carcinoid tumors elsewhere in the duodenum.

Epithelioid hemangioendothelioma of the liver: a clinicopathologic study of 137 cases.

BACKGROUND: Epithelioid hemangioendothelioma (EHE) is a rare neoplasm of vascular origin that occurs in the liver and other organs; its etiology is unknown. METHODS: The authors analyzed the clinicopathologic and immunohistochemical features of 137 patients with EHE of the liver in an attempt to identify features that might predict tumor behavior. To their knowledge, this article represents the largest series reported from one institution. RESULTS: Patients were ages 12-86 years; 84 (61%) were females and 53 (39%) were males. They presented with nonspecific symptoms such as right upper quadrant pain or weight loss. Macroscopically, the tumors usually were multiple. They typically were white, firm to hard, and ranged in size from 0.2-14 cm. Histologically, the tumors were comprised of dendritic and epithelioid cells that often contained vacuoles representing intracellular lumina. The stroma was fibrous, with myxohyaline areas. Immunohistochemically, all tumors were positive for at least one endothelial marker (factor VIII-related antigen [FVIII-RAg], CD34, and/or CD31). Treatment modalities included hepatic resection or transplantation. Although the metastatic rate in this series was 27%, the prognosis is considered much more favorable than that of other hepatic malignancies. Twenty-six patients (43%) survived > or = 5 years; 2 patients were alive and well at last follow-up after 23 and 27 years, respectively. Twenty-six of 60 patients (43%) died of their disease, 1 of whom died 28 years after discovery of her tumor. In an attempt to predict behavior of the tumor, several histologic parameters were evaluated using univariate analysis. No significant correlation was found with mitoses, Glisson's capsule infiltration, or nuclear atypia. High cellularity was significantly correlated with a poor clinical outcome (P = 0.00012), whereas the association with tumor necrosis approached significance (P = 0.057). CONCLUSIONS: EHE is a very rare clinical entity. The key to diagnosis is the demonstration of cells containing FVIII-RAg. The histology of the tumor, including nuclear pleomorphism and the mitotic count, are of no value in predicting clinical outcome. High cellularity most likely is the most significant parameter predicting an unfavorable prognosis in EHE because mitotic counts often are quite low in both low grade and aggressive tumors. Further studies are needed to identify the factors responsible for the apparent dissociation between the clinical behavior and biologic characteristics of this tumor.

Cytotoxic effects of eosinophils on renal proximal tubular epithelial cells: implications for renal allograft rejection.

Eosinophils are inflammatory cells that actively participate in the defense against large, multicellular parasites. Eosinophils are also a prominent component in the inflammatory infiltrates seen in acute allograft rejection. Their role in that process, however, remains obscure. In this study we examined in vitro the direct cytotoxicity of eosinophils against renal proximal tubular epithelial cells (PTEC) in the presence or absence of antibody and complement. Eosinophils were able to attach to the PTEC surface in both circumstances, i.e., irrespective of opsonization, or other mediation by humoral factors. The release of eosinophil granule contents (including their characteristic crystalloids) on the target cell surface and resulting PTEC injury occurred also irrespective of the presence or absence of opsonization. Thus, based on these results, the potential of direct cytotoxicity of eosinophils for PTEC exists, particularly in situations where both of these cell types are 'activated'.

Absence of human herpesvirus 8 DNA sequences in vascular tumors of the liver.

Kaposi's sarcoma-associated herpes virus (KSHV), also designated human herpesvirus 8 (HHV8), has been detected consistently in Kaposi's sarcoma, body cavity lymphoma and multicentric Castleman's disease, both in human immunodeficiency virus (HIV)-positive and -negative patients. Identification of KSHV/HHV8 DNA sequences in various benign and malignant vascular tumors in HIV-negative patients was reported in one study, but was not confirmed in several other studies. The vascular lesions, other than Kaposi's sarcoma, in which sequences could not be detected have included malignant vascular tumors of serous membranes, infantile capillary hemangiomas, and several benign and malignant vascular tumors of the spleen. We studied 30 primary benign and malignant vascular tumors of the liver; KSHV/HHV8 DNA sequences could not be detected in any. We conclude that this virus plays no role in the etiology of vascular tumors of the liver.