gms | German Medical Science

Objective: Most cancer of the anal canal are squamous cell cancer (SQC), and they are treated locally with combined fluoropyrimidine-based chemoradiotherapy in curative intention. In contrast, small cell cancer of the anal canal (SCCA) is a rare tumour entity, and its treatment should be differed from SQC. In this case report we describe the pathology of the tumour, the treatment and the clinical course of a patient with initially metastasized SCCA.

Case report: A 41-year old woman presented with locally advanced SCCA, further staging revealed the existence of hepatic and pulmonal metastases. Due to systemic spread of the SCCA four cycles of a chemotherapy using etoposide and cisplatin were administered achieving a mixed response: Restaging showed a mixed response with complete remission of the pulmonary, major response of the hepatic, but new occurrence of osseous metastases. Although new metastases had occurred during treatment two additional cycles of the chemotherapy were administered due to the good response of the pulmonary and the hepatic metastases. After the sixth cycle it came to progressive disease of the primary tumour that caused symptomatic bowel obstruction. Therefore pelvic irradiation was started to prevent the development of an ileus. During pelvic irradiation the patient’s state of mind got worse, and cerebral computed tomography showed newly developed cerebral metastases. Therefore additional irradiation of the brain was initiated. Despite adequate local treatment the patient’s state of health further deteriorated, so irradiation had to be stopped, and the patient died 6 days after the last irradiation, respectively, 10 months after the first diagnosis due to rapid tumour progression.

Conclusion: Most patients with SCCA present with locally progressive disease and initial metastatic spread due to aggressive tumour behaviour. Careful histopathologic examination including immuno-histochemical analysis is needed to obtain definitive diagnosis. Chemotherapy remains the mainstay of therapy, radiotherapy exerts additional activity in SCCA, but its indication is limited to prevent or to treat local problems and ameliorate symptoms.