Primary mixed adenocarcinoma and small-cell carcinoma of appendix: A case report (CARE-compliant).

RATIONALE: Primary extrapulmonary small-cell carcinoma (SCC) of appendix is reported very rarely. We report herein a case of mixed SCC and adenocarcinoma of appendix.

PATIENT'S CONCERN: A 70-year-old female was consulted to our Emergency Department with the right lower abdominal pain and low-grade fever for 2 days.

DIAGNOSIS: Abdominal ultrasonography revealed the perforated appendicitis with periappendiceal abscess. Postoperative histology confirmed the diagnosis of mixed SCC and adenocarcinoma.

INTERVENTIONS: After laparoscopic appendectomy, she underwent right hemicolectomy for radical surgery.

OUTCOMES: Laparoscopic appendectomy was performed and histological examination showed mixed SCC and adenocarcinoma. After confirming that there was no other organ metastasis, right hemicolectomy was performed for radical surgery. Five months after surgery, the patient expired due to multiple organ metastases.

LESSONS: Further studies are required for better understanding of disease entities, and clinical trials are needed to define adequate treatment strategies for extrapulmonary SCC.