Duodeno-colic fistula as a rare presentation of lung cancer — surgical treatment of a stage IV oligometastatic lung disease

INTRODUCTION: Rare adenosquamous carcinomas have no defined standard approach given their low incidence. They present with nonspecific imaging characteristics and are described as having worse prognosis than other lung malignancies, with greater likelihood of local invasion and early metastasis. PRESENTATION OF CASE: Male caucasian patient, 43 years, 26 pack-year smoking history, presented with watery diarrhea, early emesis and loss of 25% body weight (20 kg) in four weeks. Colonoscopy identified a left colonic mass. Abdominal CT/ultrasound showed a large fistulous lesion between the 4th portion of the duodenum and left colon. CT showed a solid mass in the right upper lung lobe. Endoscopy and transthoracic biopsy were inconclusive. En bloc D3 and D4 duodenectomy, proximal enterectomy and left hemicolectomy were performed, with inconclusive histology of the specimen. Three months later, a right upper lung lobectomy with lymphadenectomy was performed, revealing an adenosquamous carcinoma of lung origin, R0, staged as pT2pN0pM1b. Six months later, a single dural metastasis in the left cerebellopontine angle was detected and resected, with subsequent holocranial radiotherapy and systemic adjuvant chemotherapy. Patient is currently with 18 months follow-up, in good general health and with no evidence of recurrent disease. DISCUSSION: There are no specific guidelines to treat oligometastatic adenosquamous lung carcinoma. Our approach was abdominal surgery as a life-saving procedure and, months later, oncological resection of primary lung tumor and metachronous metastasis to the brain. CONCLUSION: A systematic, patient-oriented, patient-shared, multidisciplinary approach is particularly relevant when dealing with atypical presentations of rare diseases in young patients.