Anal Cancer with Mediastinal Lymph Node Metastasis.

Squamous cell carcinoma of the anal canal remains rare, with metastatic disease even less commonly reported. We present a case of a patient with both a prior history of squamous cell carcinoma of the anal canal as well as breast cancer, who was without evidence of disease for 1 year. She was subsequently found to have FDG-avid mediastinal lymphadenopathy, initially assumed to be related to her more recent breast cancer. However, a biopsy confirmed recurrent anal cancer, with HPV infection. This represents a novel site of spread for anal cancer, one not yet reported in the literature.