Squamous Cell Carcinoma With Unusual Benign-Appearing Cystic Features on Histology.

Squamous cell carcinoma (SCC) is a malignancy that arises from keratinocytes of the epidermis. Cystic variants of several types of cutaneous neoplasms have been rarely described in the literature. We report a case of biopsy-proven, well-differentiated invasive SCC treated with Mohs surgery. On frozen sections, the pathology slides showed benign-appearing cystic structures in the margins that persisted after it had appeared that the original malignancy had been cleared. After taking another Mohs stage due to clinical suspicion, additional SCC was found and was subsequently cleared after two more Mohs stages. To the best of our knowledge, this is the first report to histologically demonstrate biopsy-proven invasive SCC with benign-appearing cystic structures on frozen sections.