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The pigmented “black” neuroendocrine tumor of the pancreas
Author(s) -
Smith Sehdev Ann E.,
Levi Angelique W.,
Nadasdy Tibor,
Campbell Kurt A.,
Fishman Elliot K.,
Hruban Ralph H.
Publication year - 2001
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/1097-0142(20011001)92:7<1984::aid-cncr1718>3.0.co;2-0
Subject(s) - pathology , chromogranin a , pancreas , synaptophysin , h&e stain , stain , medicine , lipofuscin , neoplasm , fine needle aspiration , immunohistochemistry , biopsy , staining
BACKGROUND Pigmented neoplasms are extremely rare in the pancreas, and, when black pigment is identified, it often suggests the diagnosis of metastatic melanoma. The authors describe two patients with pigmented “black” neuroendocrine tumors of the pancreas. One patient had an incidental (0.5 cm) finding, and the second patient had a well‐demarcated, 4.5‐cm mass identified by computerized tomography that was consistent with an islet cell tumor. METHODS The two neoplasms were resected surgically and studied by light microscopy using hematoxylin and eosin (H&E), Fontana–Masson, and iron stains. The neoplasms were examined immunohistochemically, and ultrastructural analysis was performed. RESULTS H&E stains revealed nests of well‐differentiated cells with small, round, centrally placed nuclei. The cytoplasm of the neoplastic cells was pink and granular and contained abundant brown‐black pigment. Angiolymphatic and perineural invasion were identified in the larger neoplasm. Both neoplasms demonstrated a positive reaction with a Fontana–Masson stain, which was susceptible to bleaching, and a negative reaction to an iron stain. Immunohistochemical stains showed that neoplastic cells expressed chromogranin and synaptophysin but did not express HMB‐45, S‐100 protein, glucagon, or insulin. Ultrastructural examination revealed regular neurosecretory granules (100–150 nm) and large, irregularly shaped, electron‐dense granules with small lipid inclusions consistent with lipofuscin. CONCLUSIONS These pigmented pancreatic neoplasms are similar histologically and radiographically to the “black adenoma” of the adrenal gland. It is important to recognize these tumors, because they may mimic metastatic melanoma. Cancer 2001;92:1984–91. © 2001 American Cancer Society.