A total of 41 malignant tumors (3%) were found among the 1,312 specimens. There were 22 cases (1.7%) of primary adenocarcinoma, 3 cases (0.2%) of primary squamous cell carcinoma, 6 cases (0.5%) of metastatic carcinoma, 6 cases (0.5%) of malignant lymphoma, 3 cases (0.2%) of carcinoid tumor, and 1 case (0.08%) of gastrointestinal stromal tumor (GIST).
In the 22 cases of primary adenocarcinoma, the age ranged from 45 years to 85 years with a mean of 62 years. The male to female ratio was 14: 8. Of the 22 cases, 21 cases were biopsies and one case is tumor resection. The location was duodenum in 21 cases and jejunum in 1 case. In the present study, carcinomas of papilla Vater were excluded from the study. In the 21 cases of duodenal carcinoma, the location was first portion in 2 cases, second portion in 17 cases, and third portion in 2 cases; therefore the small intestinal carcinoma is most frequent in the second portion near the papilla of Vater. Grossly, 16 cases showed ulcerated tumors (), and 6 cases elevated tumors. Histologically, the 22 cases of adenocarcinoma were classified into 7 well differentiated, 7 moderately differentiated, and 8 poorly differentiated adenocarcinomas (). Immunohistochemically, cytokeratin (CK) was present in all cases, and p53 protein was recognized in 21 cases (). The Ki-67 labeling ranged from 40% to 95% with a mean of 71% ().
Figure 1 Adenocarcinoma of the small intestine. A: Macroscopic picture in the ileum. An ulcerated tumor is present. B: Histology of well differentiated adenocarcinoma of the duodenum. HE, x200 C: p53 expression in adenocarcinoma of the duodenum. D: Ki-67 expression (more ...)
In the three cases of squamous cell carcinoma, the age of the patients was 75, 58, and 54 years, and male to female ratio was 2:1. All cases were biopsies. All the three cases were located in the second portion near the papilla Vater of the duodenum. Grossly, all the 3 cases showed ulcerated tumor. Histologically, all the three squamous cell carcinomas were moderately differentiated squamous cell carcinomas with keratinization and intercellular bridges ( and ). Immunohistochemically, all cases expressed CK and p53 protein. The Ki-67 labeling ranged from 50% to 76% with a mean of 62%.
Histology of squamous cell carcinoma of the duodenum. A: Squamous cell carcinoma with keratinization is seen in a patient. HE, x200 B: Squamous cell carcinoma with keratinization and intercellular bridges is seen in another patient. x200.
In the 6 cases of metastatic adenocarcinoma, the origin was ovary in 1 case, pancreas in 2 cases, gall bladder in 1 case, lung in 1 case, and colon in 1 case.
In the 6 cases of lymphoma, all cases showed ulcerated tumors (). All cases were partial intestinal resection. All cases were located in the ileum. One case showed multiple tumors, and one case coexisted with colon carcinoma, and one case is associated gastric MALT lymphoma. The age of patients ranged from 69 years to 72 years with a mean of 74 years. Male to female ratio was 2:4. The clinical diagnosis was carcinoma in 2 cases, tumor in 2 cases, and suspected lymphoma in two cases. Of the 6 cases, 4 cases were diffuse large B-cell lymphomas ( and ) positive for CD15, CD20, CD45 and CD79α and negative for CK, CD3, CD30, CD45RO, CD46 and CD47. The remaining 2 cases were peripheral T-cell lymphomas positive for CD3, CD45 and CD45RO and negative for CD15, CD20, CD30, CD46, CD47, and CD79α.
Malignant lymphoma of the small intestine. A: Gross findings. Two ulcerated tumors (both end) are recognized in the ileum. B: Histology of diffuse large B-cell lymphoma. x200. CD20 stain of B. CD20 is strongly positive. x200.
In the 3 cases of carcinoid tumor, the age of the patients was 56, 34, and 81 years, and male to female ratio was 2:1. All cases were endoscopic mucosal resections. The size of the carcinoids was 8mm, 12mm, and 16 mm in diameter. Histologically, all cases were typical carcinoids (). The cells were arranged in trabecular and ribbon patterns. Immunohistochemically all the 3 carcinoids were positive for at least one of neuroendocrine markers (chromogranin, synaptophysin, neuron-specific enolase, and CD56) ().
Carcinoid tumor of small intestine. A: Histologies. Carcinoid tumor with trabecular cell arrangement is seen. HE, x200. B: synaptophysin is strongly positive. x200.
In the 1 case of GIST, the patient was 67-year old man. The case was tumor resection. Grossly, the tumor was solid and measured 6 x 6 x 5 cm. Histologically, cellular spindle cell proliferation was recognized (). Mitotic figures were seen in 4 per 50 high power fields. Immunohistochemically, the GIST cells were positive for KIT () and CD34, but negative for other mesenchymal markers. The Ki-67 labeling was 10%. The histological malignant risk was intermediate.
Gastrointestinal stromal tumor of the small intestine. A: spindle cell tumor is seen. HE, x100. B: KIT is strongly positive. x100.