Uncommon Presentation of Metastatic Squamous Cell Carcinoma of the Skin and Treatment Challenges.

BACKGROUND Squamous cell carcinoma is one of the most common keratinocytic skin cancers, the other being basal cell carcinoma. It is the second most common skin cancer after melanoma. Cutaneous squamous cell carcinoma is mostly a localized disease. The metastatic presentation is rare even in the presence of invasive disease. The metastatic potential depends on the presence of high-risk features at the time of diagnosis. Lung, liver, and bone are the frequent sites of metastasis. Local and locoregional disease undergoes excision with or without adjuvant radiation. However, we lack proper treatment paradigms for this metastatic disease. CASE REPORT We are reporting a case of an elderly female with a history of high-risk localized cutaneous squamous cell carcinoma treated with complete local excision and radiation presenting 5 years later with extensive disease to the lung and liver, abdominal nodes, and spinal fracture. The patient was not a candidate for chemotherapy due to kidney failure. On the basis of ongoing separate trials on different immunotherapies, she was started on nivolumab. CONCLUSIONS Treating metastatic cutaneous squamous cell carcinoma is a challenge considering the absence of phase III trials due to the rarity of this disease. Historically, platinum with or without 5-FU (fluorouracil), bleomycin, doxorubicin, and retinoic acid were used with variable responses. Data on epidermal growth factor receptor (EGFR) inhibitors on EGFR expressing tumors are available. However, even with the most recent reports on immunotherapy in patients with high programmed death-1 expression or high mutation burden, it is difficult to achieve good response.