Subungual metastasis from a rectal primary: case report and review of the literature.

Background: Subungual metastases from colorectal cancer are unusual and have mainly been reported in patients with lung, genitourinary, and breast cancer.

Objective: We present the case of a 72-year-old man with rectal adenocarcinoma and a subungual metastasis to the left thumb 5 years later.

Methods: A case report and a brief review of the literature of subungual metastases are given.

Results: The thumb was amputated and the patient died 6 months later with extensive metastatic disease.

Conclusion: Metastatic carcinoma should be considered in the differential diagnosis of persistent subungual masses, particularly in patients with a history of cancer. The prognosis with such lesions is generally poor.