Misdiagnosed squamous tumor metastatic to sentinel lymph node

    A 78 year old woman presented to her dermatologist with a 2.5 cm nodule on her left shin.  The clinical differential diagnosis included squamous cell carcinoma and nodular amelanotic melanoma.  A biopsy was performed and initially interpreted as invasive squamous cell carcinoma with adjacent basal cell carcinoma.
    The diagnosis was revised after review of the biopsy. Based upon our revised diagnosis, a radiographic survey for metastatic disease, along with a re-excision and sentinel lymph node biopsy were performed.