Extrapulmonary small cell carcinoma of the liver treated with chemotherapy and durvalumab

Two basic criteria must be met for the diagnosis of extrapulmonary small cell carcinoma (EPSCC): the tumor must present histological characteristics of small cell carcinoma and a primary small cell lung carcinoma must be ruled out. We present the case of a 52-year-old woman who presented 8 months prior to consultation with an increase in abdominal circumference, epigastric pain and early satiety. Abdominal MRI showed an enlarged liver secondary to a mass affecting segments IV, V, VI, VII and VIII of 16.9 × 9.4 cm. Biopsy of the liver lesion was performed: small, round, blue cell neoplasm; immunohistochemistry revealed positivity for CKA1/A3, chromogranin, synaptophysin, CD56 and TTF-1. The diagnosis of EPSCC of the liver was made. It was decided to start systemic chemotherapy treatment with carboplatin, etoposide and durvalumab with clinical improvement of the symptoms. The patient died 10 months after starting chemoimmunotherapy treatment. Optimal treatment of EPSCC is generally extrapolated from small lung cell cancer. There is insufficient evidence to routinely recommend the use of immunotherapy in this group of patients.