Mixed neuroendocrine and squamous cell carcinoma of the colon: A case report and literature review

INTRODUCTION: The occurrence of Neuroendocrine Carcinoma (NEC) of the colon is <2% of all colon cancers. Squamous Cell Carcinoma (SCC) is even more unusual and has an occurrence in the colon as low as 0.1% of colon cancers. Coupled together mixed NEC-SCC, is nearly unheard of. SCC of the gastrointestinal tract is usually found in the esophagus and rectum, rarely are there squamous cells even present in the colon. PRESENTATION OF CASE: A 62-year-old female presented with abdominal pain and a palpable mass in the left lower quadrant. CT scan revealed a poly-lobulated mass in the left abdomen attached to the left colon. A left hemicolectomy was performed. There were no distant metastases at the time of diagnosis. Microscopic examination revealed NEC mixed with SCC demonstrated by keratin pearl formation. DISCUSSION: NEC and SCC individually are unusual in the colon but together are extraordinarily rare. Histologically, the NEC in this case demonstrated squamous cell differentiation with keratin pearl formation. The median survival in studies of patients with colonic NEC is 5–10 months due to the aggressive behavior and lymph node metastases, which were present in this case. There is insufficient literature addressing ideal adjuvant therapy after resection of mixed NEC and SCC of the colon. CONCLUSION: We present the first case of primary colon mixed NEC and SCC which presented as abdominal pain. There is a current absence of ideal therapy recommendations in the medical literature following resection of mixed NEC and SCC of the colon.