Localized Colonic Small-Cell Carcinoma with Pathological Complete Response after Neoadjuvant Cisplatin and Etoposide: A Case Report

Abstract

Extrapulmonary small-cell carcinoma (SCC) is a rare neoplasm that shares certain features with its pulmonary counterpart and occurs predominantly in the gastrointestinal tract (GIT). It is a high-grade and poorly differentiated neuroendocrine tumor, usually diagnosed in advanced stages, with a poor prognosis and few therapeutic options in that setting. This is a case report of a 77-year-old Spanish male patient with localized SCC of the colon, who presented a pathological complete response in the surgical specimen after neoadjuvant chemotherapy with cisplatin and etoposide. To date, 5 years after surgery, the patient remains without evidence of tumor recurrence. As clinical guidelines for the management of this entity are lacking, and therefore its management has not been standardized, an attempt to summarize the current evidence in the literature was made.

Keywords: case report; colonic small-cell carcinoma; extrapulmonary small-cell carcinoma; neoadjuvant chemotherapy; pathological complete response; small-cell carcinoma (SCC).

Figure 1

Colonoscopy image of the sessile tumor lesion.

Figure 2

Light microscopy image of tumor biopsy. (A) Hematoxylin–eosin (H&E) stain 5×. Large intestine mucosa infiltrated by a solid neoplasm composed of small cells with abundant necrosis. (B) H&E stain 10×. Tumoral cells show scant cytoplasm and nuclear pleomorphism. (C) Tumoral cells stain positive for synaptophysine. (D) ki67 proliferation index above 90%.