Dhiren D. Dhanji, Jan Kokavec, Svetlana Cherepanoff, Con Petsoglou

Purpose: Spindle cell carcinoma (SPCC) is a rare and aggressive biphasic subtype of squamous cell carcinoma which rarely affects the conjunctiva. In this condition, neoplastic epithelial cells undergo epithelial to mesenchymal transition developing an invasive, migratory phenotype which morphologically resembles sarcoma. Osteoclast-like giant cells (OLGC) may be found in SPCC or within the metatypical carcinoma spectrum; both of which are more aggressive than conventional squamous cell carcinomas. We present a novel case of conjunctival SPCC with OLGCs to highlight that thorough immunohistochemical analysis and proactive clinical manage- ment are essential.

Methods: We report the first case of primary conjuncti- val SPCC with clearly described OLGCs.

Results: An 89-year-old male presented with rapid enlargement of an inflamed perilimbal lesion, which was treated with excisional biopsy and cryotherapy. Histopathological and immunohistochemical analysis favoured a diagnosis of SPCC with OLGCs; demonstrating spindle cells intermixed with conspicuous OLGCs, squamous differentiation in continuity with surface epithelium, positive p63 and cytokeratin immunostaining and absence of mesenchymal or melanocytic markers. Despite further surgical excision, rapid growth occurred over a 4-month period with macroscopic extension abutting the lacrimal gland and lateral rectus insertion. The patient ultimately under- went an exenteration and local radiotherapy was offered.

Conclusions: This case of locally aggressive primary conjunctival SPCC with OLGCs demonstrates how imperative proactive treatment and follow-up is once diagnosed with thorough histopathological and immunohistochemical analysis. Despite insufficient data in the literature to determine the prognostic influence of OLGCs, its frequency in SPCC outside of the conjunctiva may indicate it is a poor prognostic indicator.