Anal Metastasis from Lung Cancer: Report of a Case and Systematic Review of the Literature.

Lung cancer is the most frequent cancer, accounting for over 2 million new cases per year worldwide. In Romania, the cancers with the highest incidence are lung cancer for men and breast cancer for women. Cancer-related deaths follow the same pattern. More than 50% of the patients with lung cancers have distant metastases at the time of diagnosis. Metastases from lung cancer occur mainly in the brain, bones, liver, and adrenals. Anal metastases from primary lung cancer are extremely uncommon. As far as we know there are only 12 cases reported in the literature until now. Case report: Case report and systematic review. We performed a systematic literature search in PubMed using the following MeSH terms: "lung cancer metastasis" AND "anal" OR "anus" OR "perianal". The search was conducted from the beginning of the database onwards. No language exclusion criteria were used. We report the case of a patient with advanced lung adenocarcinoma presenting with a painful, ulcerated and bleeding anal tumor. The anal tumor was excised with primary wound closure in spinal anesthesia. The pathology report and the immunohistochemistry of the specimen revealed metastasis of the lung adenocarcinoma. The review included 12 papers reporting 12 cases. The male/female ratio was 3/1. The average age was 62,16 years. Among these 12 patients, one had a SCLC. From the remaining 11 cases with NSCLC, 4 were adenocarcinomas, 4 squamous cell carcinomas, two anaplastic carcinomas and one mucoepidermoid carcinoma. The anal metastases were synchronous in 4 cases and metachronous in the rest of 8 cases. Since 2006 immuno-histochemistry plays an important role in the diagnosis of these metastases. Our patient presented an anal metastasis of a lung adenocarcinoma that was masquerading as a complicated hemorrhoidal disease. Because anal masses can be easily misdiagnosed, patients with lung cancers and anal or perianal complaints should be evaluated for metastatic disease. Medical teams that are managing such cases must be aware of this rare but possible situation. Immunohistochemistry plays an important role in establishing the diagnosis for the anal or perianal tumours in patients with lung cancer.