Induction of lymphomas on implantation of human oral squamous cell carcinomas in nude mice.

Cancer cells from five oral cancer patients and pleomorphic adenoma cells from one individual were inoculated as single cell suspension into subcutis of 30 Swiss nude mice and tail vein of additional 30 mice. Further, tumor tissue pieces from three oral cancer patients were xenografted s.c. in 18 nude mice, and 10 mice were kept as controls. In animals implanted with tumor pieces, 7/18 (39%) mice, developed squamous cell carcinoma at the site of inoculation within 8-15 days, while tumors were not observed in mice inoculated with single cell suspension, up to 60/90 days. In 8/68 (12%) mice, white foci were observed in several tissues, with hepatomegaly and splenomegaly noted in 27/68 (39%) mice. Histopathological examination of various tissues revealed presence of large cell lymphoma in several organs in 14/68 (21%) mice. No regional or distant metastasis of the implanted oral tumor cells was detected. Mice injected with cells from pleomorphic adenoma, also demonstrated large cell lymphoma in 2/10 (20%) mice, whereas none of the 10 control animals showed any gross abnormalities or microscopic abnormalities in several organs. 2/16 (12%) lymphomas exhibited positive reaction with mouse B cell antibodies illustrating the murine origin of the lymphomas, and these were immunophenotyed as B cell lymphomas. The lymphomas were also examined with mouse T cell antibodies and none reacted positively with the mouse T cell antibodies. The lymphomas also failed to react with human T cell, B cell and human Leucocyte common antigen (LCA) antibodies, indicating that the induced lymphomas were not of human origin. The tumor specimens from seven of eight oral cancer patients and the pleomorphic adenoma patient induced lymphomas in nude mice. Thus it appears that xenografting oral tumor cells into nude mice may cause induction of the murine lymphomas, and this needs further investigation.

Pseudolymphomatous phase of Kikuchi-Fujimoto disease.

Kikuchi-Fujimoto lymphadenitis is a distinctive entity which is easily recognised in its classical histology. However, cases which are biopsied in the early stage of the disease, before entering the necrotic phase may be misdiagnosed as non-Hodgkin's lymphoma. Ten cases of Kikuchi-Fujimoto disease which mimicked non-Hodgkin's lymphoma and in which less than 10% of the lymph node was occupied by necrosis were chosen for this study. The patients included 4 males and 6 females with an age range of 15-40 years. Eight patients presented with cervical lymphadenopathy. The pathologic areas ranged from 70% to 95% of the total nodal area. The features that helped distinguish this lesion from non-Hodgkin's lymphoma were: 1) a sprinkling of karyorrhectic debris throughout the node 2) plasmacytoid monocytes as well as "histiocytes" in the company of transformed lymphocytes (immunoblasts) 3) enlarged mottled T-zone areas, and 4) presence of residual lymphoid follicles. Follow up on six patients revealed no evidence of disease.

Collision tumor with three components at esophagogastric junction.

We report a 70-year-old man with a collision tumor consisting of three neoplasms at the gastroesophageal junction. The component tumors were squamous carcinoma at the esophageal and, adenocarcinoma at the gastric end, and leiomyoma within.

Rhabdoid phenotype in squamous carcinoma. A report of two cases.

We report two cases of squamous carcinoma in which a prominent rhabdoid phenotype was seen. The tumors which occurred in the buccal mucosa of a 70 year old man and the skin of a 85 year old man were positive for cytokeratin and epithelial membrane antigen indicating their epithelial nature. Co-expression of vimentin was also noted. The aggressive nature of the rhabdoid component is confirmed by the fact that the cervical lymph node metastasis in case I was also rhabdoid.

Psammomatous carcinoid tumor of the duodenum.

We report a case of psammomatous calcification in a carcinoid tumor of the ampulla of Vater. Although the tumor was glandular, its neuroendocrine nature was proved using chromogranin immunostain.

Heterotopic ossification in colorectal adenocarcinoma [corrected]

Heterotopic ossification in Adenocarcinomas of the colon is uncommon. The clinical presentation of these patients is similar to those without osseous metaplasia. Its importance lies in the fact that it may be misdiagnosed for a carcinosarcoma. Which has a poorer prognosis. These two cases are reported because of its rarity.