Unusual eyelid tumors with sebaceous differentiation in the Muir-Torre syndrome. Rapid clinical regrowth and frank squamous transformation after biopsy.

An unusual eyelid tumor with sebaceous differentiation developed in two 70-year-old men and each had an earlier history of one or more colonic carcinomas--the so-called Muir-Torre syndrome. These eyelid tumors were both behaviorally and histopathologically different from previously documented cutaneous neoplasms in this syndrome. In the first case, a sebaceous adenoma took multifocal origin from the epidermis and exhibited an interanastomosing retiform growth pattern in the underlying dermis; the lesion rapidly recurred as a keratoacanthoma after subtotal excision. In the second case, a conjunctival tumor with features of a poorly differentiated squamous cell carcinoma manifested focal evidence of sebaceous differentiation. Again, after an incisional biopsy, the latter tumor rapidly regrew and transformed into a well-differentiated squamous cell carcinoma with massive central necrosis. Although sebaceous carcinoma of the eyelids does not appear to presage the Muir-Torre syndrome, any benign sebaceous or transitional squamo-sebaceous neoplasm should be considered a possible manifestation of this syndrome. Both clear-cut benign and transitional sebaceous neoplasms should also be recognized as having the potential to undergo an ominous clinical regrowth upon subtotal excision and a complete squamous transformation.