Mahendra Ranchod

A study was made of 117 patients who presented with gastrointestinal lymphoma. The occurrence was 48 in the stomach, 37 in the small intestine, 13 in the ileocecal region, two in the appendix and 11 in the large intestine. In six cases, multiple sites in the gastrointestinal tract were involved, but in five cases this appeared to be secondary to massive mesenteric or retroperitoneal lymph node disease. Using Rappaport's classification, diffuse histiocytic lymphoma was the most frequent histologic type and constituted 60% of the cases. Nodular lymphomas comprised 10% of the total, nodular poorly differentiated lymphocytic lymphoma forming the majority of this group. Ten of the lymphomas were undifferentiated, 5 of Burkitt's type and 5 non-Burkitt's type. Five were Mediterranean-type lymphomas associated with plasma cell infiltration of the adjacent mucosa, and only two cases of primary Hodgkin's disease were encountered. Two lymphomas could not be classified. Eight percent of the cases showed plasmacytoid changes and were classified as a distinct subgroup of the parent lymphoma rather than as examples of extramedullary plasmacytoma. Gastrointestinally lymphomas occurred most frequently during the fourth to seventh decades. However, nine lymphomas occurred in children younger than 16 years of age. In comparison to adults, the childhood lymphomas showed a number of notable differences with respect to sex distribution, site of involvement and histologic type. Information concerning the extent of the disease at the time of diagnosis was available in 75 cases. Of these, 49% of the lymphomas were confined to the affected viscus and 33% had associated regional lymph node involvement; the remaining 18% had mode widespread disease. In 44 patients information on the spread of disease was available and in 48% there was extra abdominal spread. Prognosis appeared to correlate best with the stage of the disease rather than the histologic type.

One hundred smooth muscle tumors arising in the gastrointestinal tract and retroperitoneum were reviewed in an attempt to define criteria for the diagnosis of leiomyosarcoma in these sites. On the basis of aggressive behavior, 56 of these neoplasms were diagnosed as leiomyosarcoma. Mitoses were found to be the most useful indicator of malignancy; all of the tumors with five or more mitoses/10 HPF behaved aggressively and smooth muscle tumors with this degree of mitotic activity should be diagnosed as leiomyosarcoma. A paucity of mitoses, however, is no assurance of benignity as nearly 40% of the leiomyosarcomas in this series had fewer than five mitoses/10 HPF. Tumor cell necrosis was closely associated with aggressive behavior even when mitoses were infrequent and it is doubtful that benign smooth muscle tumors develop extensive tumor cell necrosis. In the absence of the requisite number of mitoses or tumor necrosis, it is difficult to distinguish some leiomyosarcomas from leiomyomas, but tumor size, cellularity and cellular atypia may be helpful parameters when assessed together. The importance of these criteria in different anatomical sites is discussed. It is emphasized that the criteria for the diagnosis of leiomyosarcoma of the uterus do not apply to non-uterine smooth muscle tumors. The actuarial 2-year survival rate was as follows: gastric leiomyosarcoma, 40%; small intestinal leiomyosarcoma, 60%; and retroperitoneal leiomyosarcoma, 16%.

Based on a study of 26 cases and a review of the literature, lymphoid hyperplasia of the gastrointestinal tract can be categorized into four clinicopathologic groups: focal lymphoid hyperplasia of the stomach, focal lymphoid hyperplasia of the small intestine, focal lymphoid hyperplasia of the rectum, and nodular lymphoid hyperplasia of the gastrointestinal tract. The focal lesions are single, variably circumscribed, and produce thickening of the wall of the affected part of the viscus. While a substantial number of the gastric lesions are associated with chronic peptic ulcers, ulceration is absent or insignificant in focal lesions located in the intestine. The extent of the infiltrate may range from involvement of the mucosa and submucosa only to infiltration of the full thickness of the wall. Nodular lymphoid hyperplasia of the gastrointestinal tract produces multiple discrete mucosal nodules in a variable segment of the small intestine, large intestine, or both. Gastric involvement is rare. The lymphoid infiltrate is confined to the lamina propria and superficial submucosa. Nodular lymphoid hyperplasia is most commonly encountered incidentally during radiologic examination or at autopsy, but it also occurs in association with hypogammaglobulinemia, especially late-onset acquired hypogammaglobulinemia. Lymphoid hyperplasia of the gastrointestinal tract can be distinguished from malignant lymphoma by the polymorphic nature of the infiltrate, the absence of significant cytologic atypia, and the presence of reactive follicles within the lesion.

Thirty-five cases of spindle-cell carcinoid tumors of the lung were studied. Fifteen patients were male and 20 female, and they ranged in age from 33 to 78 years, with a mean of 57.6 years. Eleven neoplasms were located in the left lung and 23 in the right lung; a disproportionately large number of neoplasms were present in the right middle lobe. The tumors were most commonly encountered as an incidental finding on chest roentgenogram. None of the patients had unequivocal evidence of the carcinoid or any other endocrine syndrome. All but two of the lesions were located n the periphery of the lung and most were subpleural. They ranged in size from 0.7 to 4 cm, with 82% of the neoplasms having a maximum dimension of 2 cm or less. Microscopically, the neoplasms were composed predominantly or entirely of spindle cells which were fairly uniform in length in any single lesion, but showed moderate variation from case to case. The shorter spindle cells were often arranged in an "organoid" pattern, while the neoplasms composed of larger spindle cells were more "mesenchymal" in appearance. Silver stains were performed on 12 cases and all were argyrophil-positive. Cytoplasmic dense-core granules were identified in all four neoplasms examined ultrastructurally. Twelve cases were treated by wedge resection or segmental resection, and 18 cases by lobectomy. Hilar lymph nodes were removed from seven patients, and in two there were microscopic lymph node metastases. One other patient had a single microscopic bony metastasis. Follow-up information was available for 22 patients and ranged from 1 to 13 years with a mean of 5.4 years. None of the patients have had metastases other than those described above and none of the patients had died of their disease.

A lung, which was surgically removed from a patient who had oat cell carcinoma, contained multiple tumorlets and showed extensive Kultschitsky-type cell proliferation of bronchial and bronchiolar mucosa. On the basis of light and electron microscopic observations, it is shown that pulmonary tumorlets arise from focal areas of bronchial and bronchiolar Kultschitsky cell proliferation which may advance to luminal obliteration. Involvement of the pulmonary parenchyma takes place by extension of these newly proliferated cells along the terminal branches of the bronchiolar tree or by penetration of the bronchial or bronchiolar wall; the latter process evokes a striking proliferation of connective tissue which forms the matrix in which the cells of some fully developed tumorlets are embedded. Because of striking morphologic similarities between tumorlets and spindle cell carcinoid tumors, and the proven origin of tumorlets from pulmonary Kultschitsky-type cells, it is suggested that the more complete and histogenetically acceptable term "carcinoid tumor-let" be used to distinguish this lesion from other forms of epithelial proliferations in the lung.