Small-cell cancers, and an unusual reaction to chemotherapy: Case 3. Small-cell carcinoma of the stomach

Unusual case of small cell gastric carcinoma: case report and literature review

BACKGROUND

Small cell carcinomas are among the most aggressive, poorly differentiated, and highly malignant of the neuroendocrine tumors (NETs). Of which, small cell gastric carcinoma is a rare small cell neuroendocrine tumor. The purpose of our study was to present this case and perform a comprehensive literature review.

METHODS AND RESULTS

We review a case of small cell gastric carcinoma that is particularly unusual in that it occurred in a woman from the US when the majority of cases of small cell gastric carcinoma have been reported in men from East Asia, and more specifically, from Japan. The diagnosis was made after endoscopy revealed a large ulcerated mass in the gastric cardia of Borrmann type 3. Biopsies revealed multiple small basophilic cells underlying the squamous epithelium of the esophagus and cardiac mucosa, indicating the presence of a tumor at the gastroesophageal junction. Immunostaining established the diagnosis with positive stains for chromogranin, synaptophysin, and CD56. Our patient is being treated with chemotherapy, but many different treatment regimens have been tried for small cell gastric carcinoma with variable success.

CONCLUSIONS

Overall prognosis for small cell gastric carcinoma is dismal. Neuroendocrine tumors in general have variable clinical behaviors and prognosis is dependent on the neuroendocrine tumor type. The adoption of a standardized classification system for neuroendocrine tumors could improve the recognition of infrequently encountered neuroendocrine tumors like small cell gastric carcinoma and will enhance strategies for treatment and thus improve prognosis for patients with these rare and aggressive tumors.

Extrapulmonary small cell carcinoma: single center experience with 61 patients

Extrapulmonary small-cell carcinoma (EPSCC) is a clinicopathological entity distinct from small-cell carcinoma (SCC) of the lung. The aim of this study was to review the clinico-pathologic features, treatment modalities, and factors prognostic for survival in patients with EPSCC. We retrospectively reviewed the medical records of patients with EPSCC diagnosed between January 1995 and July 2004 at the Asan Medical Center. We identified 61 patients with EPSCC, 37 with limited disease (LD) and 24 with extensive disease (ED). The most common primary sites were the gastrointestinal (GI) tract (56%) and uterine cervix (18%). Overall survival (OS) at 1 and 3 years was 59% and 29%, respectively, with a median survival of 16 months (range, 1 approximately 56 months). Treatment information was available for 51 patients, 34 with LD and 17 with ED. Of the 34 LD patients, 25 underwent surgery. Surgery was the only treatment modality in five patients, two of whom remained alive and disease free at last follow-up, 27 and 47 months after surgery, respectively. Adjuvant chemoradiotherapy was administered to 11 patients, nine of whom (82%) had distant failure with a median overall survival of 23 months. Of the eight patients who received adjuvant chemotherapy, four (50%) had distant failure, with a median survival of 21.7 months. In univariate analysis, advanced disease status, as measured by VALSG (LD vs. ED) stage, was a significant prognostic factor for OS (p<0.001). Interestingly, there were no statistically significant differences in progression-free survival or OS between patients with pure (n=45) and mixed (n=16) EPSCC. Overall, the response to various treatment modalities and the median survival time observed were discouraging. Patients with GI primary tumors had poorer prognoses than those with primary tumors at other locations. Fifty six percent of patients with a GI primary tumor had ED at the time of diagnosis, whereas 100% of patients with SCC of the uterine cervix had LD at the time of diagnosis and showed a favorable clinical course. The majority of patients with LD SCC who underwent surgery, followed by adjuvant chemotherapy or chemoradiotherapy, showed tumor recurrence and/or systemic metastases. Clinical trials are needed to define adequate treatment strategies for EPSCC.

Primary colorectal small cell carcinoma: a clinicopathological and immunohistochemical study of 10 cases

Colorectal small cell carcinoma (SmCC) is a rare tumor with an aggressive course. The aim of this study is to summarize our experience with this tumor and to highlight its immunohistochemical profile. Ten cases of colorectal SmCC were identified in our files and a panel of immunostains was performed. Follow up was available for the average of 3 years, during which 7 patients died and 3 were alive with disease. All cases were positive for LMWK, CK 19 and pancytokeratin but were negative for TTF-1 and CA 125. EGFR was positive in 7 cases. TTF-1 negative staining may be valuable in differentiating it from its pulmonary counterpart. CDX2, mCEA, CD56, synaptophysin, NSE and chromogranin can help differentiate it from non-endocrine poorly differentiated adenocarcinoma. The expression of EGFR in a subset of patients has not been reported earlier and has to be evaluated in larger series to assess its role in the planning of targeted biologic therapy.

A case of primary gastric small cell carcinoma with a rare pattern of lymph node metastasis

We report a very rare case of primary gastric small cell carcinoma (GSCC) that was accompanied with gastric tubular adenocarcinoma. A male in his 60s had an elevated tumor with a central ulceration in the middle stomach. The patient underwent a distal gastrectomy with lymph node dissection. The pathological examination showed two separated lesions of the stomach, which contained the components of primary GSCC and primary gastric tubular adenocarcinoma. Immunohistochemical (IHC) examination demonstrated that the tumor cells in the small cell carcinoma stained positive for synaptophysin, chromogranin A, and neural cell adhesion molecule (NCAM). GSCC cells and adenocarcinoma cells independently metastasized to each regional lymph node. Further studies on the biological behavior of individual tumors may allow the development of new treatment strategies for GSCC.

Combined small-cell carcinoma of the stomach: p53 and K-ras gene mutational analysis supports a monoclonal origin of three histological components

Primary small-cell carcinoma (SmCC) is extremely rare in stomach. We reported an autopsy case of combined gastric SmCC with p53 and K-ras mutational analysis. Histologically, the tumour was composed of well-differentiated adenocarcinoma surrounding the central dominant SmCC component with scattered nests of squamous cell carcinoma. Immunohistochemically, all the neoplastic components revealed strong expression for p53 protein. Based on these findings, we hypothesized that these histologically different components originated from a same progenitor cell that possessed p53 mutation. Using Laser-capture microdissection technique and mutational analysis, we identified the same point mutations of p53 gene (A-->G transversion in codon 239) and K-ras gene (G-->A transversion in codon 13) in all the neoplastic components, but not in the adjacent normal gastric epithelium. Our results strongly support a hypothesis that the combined SmCC of stomach in this case was of monoclonal origin.