Squamous cell carcinoma of the foot mimicking osteomyelitis: a case report

Bone invasion by squamous cell carcinoma (SCC), other than the regions of the head and neck, is very rare. To our knowledge, and following a search of the National Library of Medicine's Medline database via PubMed, such invasion involving the foot in the absence of osteomyelitis has not been reported. In this case report, we present a rare case of a patient with an ulcerative lesion overlying a SCC in the plantar foot that clinically and radiographically mimicked osteomyelitis of the third digit and third metatarsal. This type of tumor, often referred to as verrucous carcinoma, is characterized by its locally aggressive nature, low potential for metastasis, and well-differentiated nature of SCC. The initial surgical approach consisted of wide excision of the malignant neoplasm, along with partial third ray resection. After pathologic evaluation, which confirmed incomplete excision of the malignancy and absence of osteomyelitis, subsequent surgical intervention was required. Lisfranc's disarticulation/amputation was recommended, not only to ensure removal of any questionable remnants of the SCC, but also to provide a functional limb for ambulation. Although the incidence of SCC is relatively common, the disease process is often under recognized, and podiatrists should consider such malignancy in the presence of chronic ulcerative foot lesions.