Although neuroendocrine differentiation is a characteristic feature of tumors of the adrenal medulla, cortical tumors may also rarely be differentiated into medullary element.
Recently we experienced such a case of adrenal cortical tumor having features of both cortical and medullary tumor.
The patient was an 11-year-old girl who was incidentally found to have a left adrenal mass. Laboratory results showed elevated serum cortisol, aldosterone, renin, and epinephrine with high excretion of urinary metanephrine. Urine vanillyl mandelic acid and 17-ketosteroid remained within normal limits. Histologic featuresof a 6 cm round yellowish tumor were ambiguous to decide the orgin of this neoplasm.
Cortical element predominated in the tumor with minor areas of pheochromocytomatous feature. Immunohistochemically, the tumor cells were positive for vimentin, neuron specific enolase, and epithelial membrane antigen. Ultrastructural examination revealed scattered membrane bound dense core granules in the tumor cells of medullary differentiation, measuring 150~500 nm in average diameter. Cortical tumor element showed corresponding ultrastructural features. These results indicate that this is a case of adrenal cortical tumor with features of neuroendocrine differentiation.
In order to correlate the frequency of neuroendocrine cells with pathologic parameters in gastric adenocarcinomas, immunoperoxidase staining for neuron specific enolase was performed on 250 consecutive cases of surgically resected gastric adenocarcinomas(201 advanced gastric carcinomas[AGCs], 49 early gastric carcinomas[EGCs] and 2 cases of gastric carcinoid tumors. Of the 252 cases of gastric carcinomas, pure exocrine carcinomas were 174 cases(69%), pure neuroendocrine(NE) carcinomas 2 cases(0.8%), mixed exocrine and NE carcinomas 32 cases(12.7%), and exocrine carcinomas with occasional NE cells 44 cases(17.5%). The frequency of gastric carcinomas with NSE-positive cells increased with age proportionally.
NSE positivity was higher in polypoid or fungating tumors(AGC Borrmann type I, II, EGC I and IIa) than ulcerative or scirrhous tumors. There was no significant difference in frequency of NSE-positive cells by histologic type and differentiation of gastric adenocarcinomas. The above findings reflect that most gastric carcinomas are heterogeneous in their constituents and suggest that both exocrine and neuroendocrine carcinomas are the expression of the extreme ends of the exocrine-endocrine differentiation spectrum based on the assumption that they develop from the pluripotent stem cells differentiating into both exocrine endocrine carcinomas.