Malignant gastric neuroendogrinomas. Ultrastructural and biochemical characterization of their secretory activity

Atypical gastric carcinoids

Four examples of infiltrating gastric tumours which had light microscopic features suggestive of carcinoid or oat-cell carcinoma are documented. Histological and ultrastructural findings indicated that these tumours were atypical carcinoids. A spectrum of endocrine cell neoplasia in the stomach analogous to that observed in the bronchus is postulated. It is felt that increased recognition of poorly differentiated endocrine tumours of the stomach might be of prognostic and therapeutic importance.

Mucin-producing carcinoid ("composite tumor") of upper third of esophagus: a variant of carcinoid tumor

An unusual upper esophageal polypoid tumor was found to be predominantly a carcinoid tumor and in part a mucin-producing adenocarcinoma. A review of literature showed this to be a unique tumor in this location.

Primary oat cell carcinoma of the larynx: a case report and review of the literature

A case of an extrapulmonary oat cell carcinoma arising in the larynx of a 45-year-old male is described. Ultrastructural study demonstrated numerous neurosecretory granules in the tumor cells identical to those described in oat cell carcinomas of the lung. Primary oat cell carcinomas of the larynx are highly malignant neoplasms. Of six previously reported acceptable cases of this rare entity, with adequate followup, all but one has died of tumor within 14 months of diagnosis. The present patient is alive without evidence of tumor 15 months following diagnosis. Aggressive therapy consisting of a combination of surgery, radiation therapy and systemic chemotherapy was utilized in this case. The use of such aggressive combination therapy appears indicated in cases of primary oat cell carcinoma of the larynx if improved survival is to be achieved.

Ultrastructural and biochemical analysis of "undifferentiated" pulmonary carcinomas

Seven cases of "undifferentiated" pulmonary carcinoma were studied ultrastructurally; five were of the typical oat cell variety and the remaining two consisted of larger cells. In three of the former and both of the latter cases neurosecretory-like granules were demonstrated. Biochemical analysis of tumor tissue extracts revealed 5-hydroxy-3-indoleacetic acid, vanilylmandelic acid, and catecholamine activity in all instances. No hormonal syndrome or metabolic abnormality was detected in any of the patients. The concomitant morphologic demonstration of neurosecretory-like granules and the presence of 5-hydroxy-3-indoleacetic acid, vanilylmandelic acid, and catecholamines in neoplastic tissue would provide further evidence that these tumors may indeed arise from bronchial endocrine cells and could therefore be classified within the group of neuroendocrine carcinomas. Also it seems apparent that these neuroendocrine bronchial carcinomas may include tumors consisting of cells somewhat larger than the typical oat cell. The observation of 5-hydroxy-3-indoleacetic acid, vanilylmandelic acid, and catecholamine activity in two oat cell carcinomas in which neurosecretory granules could not be demonstrated poses an interesting problem whose solution may only derive from further studies.