Clinicopathological correlation of Merkel cell carcinoma of the eyelid

Abstract

Purpose : To report the clinicopathologic findings of five cases of Merkel cell carcinoma of the eyelid. Methods : In a non-comparative, consecutive case series, the database of Florida Lions Ocular Pathology Laboratory was searched for surgical specimens diagnosed with Merkel cell carcinoma from the time-period of 1977 to 2017. The histopathologic slides and clinicopathologic features were evaluated. Results : The diagnosis of Merkel cell carcinoma was established by light microscopic examination of formalin fixed, paraffin embedded tissue in the eyelid and conjunctiva of five patients. Two cases were from the left lower lid, two from the left upper lid and one from the left conjunctiva. All five patients were male. Mean age was 78.6 years (range 68-86 years). Findings on clinical presentation included three patients presenting with eyelid masses, one patient with eyelid and orbital masses, and one with a conjunctival mass. The size of the lesions ranged from 0.5 cm to 3.3 cm. The patients underwent biopsy followed by Mohs excision (1), exenteration (1) and excision (3). Histopathologic exam revealed large basophilic cells with scant cytoplasm and granular nucleoplasm. Immunohistochemical stains including epithelial membrane antigen, neuron specific enolase, cytokeratin-7, cytokeratin-20, synaptophysin and chromogranin were performed. Two patients were found to have metastasis to the parotid gland, one patient to the preauricular lymph node, and one patient had local recurrence. Conclusions : Herein we illustrate the clinical and pathological findings of Merkel cell carcinoma of the eyelid. Merkel cell carcinoma is a rare and aggressive malignancy of the eyelid. Few reports are present in the literature on Merkel cell carcinoma of the eyelid. This is also the first report describing Merkel cell carcinoma of the conjunctiva without an identifiable skin lesion. Early identification of Merkel cell carcinoma is important as Merkel cell carcinoma is highly aggressive and is associated with significant recurrence rates and metastases.