Poorly differentiated squamous cell carcinoma with osteoclast-like giant cells: A Case Report

Abstract

Squamous cell carcinoma is a common malignant tumor of the skin. However, squamous cell carcinoma with osteoclast-like giant cells (SCC-OGC) is a rare cutaneous tumor. Although the entity has been described in other sites, diagnosis is often difficult due to its moderate to poor differentiation. Herein we present the clinical, radiological, and pathological characteristics of a case of a 57-year-old female who presented with a poorly differentiated scalp mass with numerous bland OGCs. The mass was confirmed to be an SCC-OGC by focal positivity for p63 and CK5/6. By contrast, the OGCs were negative. We hypothesize that this tumor originated from a cyst because it was well defined and lacked the epidermal and dermo-epidermal junctional changes of SCC. Considering the aggressiveness of this variant, the patient developed lung metastasis of the tumor after 10 weeks of follow-up. The histological findings and differential diagnosis are discussed in this article.