Think Beyond Recurrence-Unexpected Diagnosis at a Rare Site

Primary squamous cell carcinoma of the breast is a very rare tumor accounting for less than 0.1% of all invasive breast carcinomas. It is a very aggressive, hormone receptor negative and treatment refractory tumor associated with poor prognosis. Verrucous carcinoma is a low-grade rare variant squamous cell carcinoma of skin and mucosa. It is characterized by slow growth, minimal local invasion, and rare metastasis, hence associated with an excellent prognosis. Verrucous carcinoma is more common in aerodigestive tract and anogenital region. The most common cutaneous sites are the hands and feet. We report a unique case of verrucous carcinoma of the chest wall diagnosed in a patient who had carcinoma breast post-mastectomy, which was suspected to be a local recurrence. The mode of presentation, the uncommon site of the disease, and the differential diagnosis make it an interesting case.

The online version contains supplementary material available at 10.1007/s13193-022-01598-4.