A rare pearl for the evaluation of eyelid lesions

Abstract

Background: Eyelid lesions are of special interdisciplinary interest that are primarily managed by dermatologists and ophthalmologists. Due to the unique anatomical characteristics, eyelid lesions can have different characteristics, appearance, and clinical behavior. Most eyelid lesions are benign, but it is important to rule out neoplastic lesions early to provide appropriate management, limit morbidity and disfigurement, and screen for systemic involvement. Case history: A 79-year-old male patient presented to an eye clinic with a pearly and translucent pink-blue 3 mm papule on the right lower eyelid margin with madarosis but no ulceration. He also had blepharitis and seborrheic dermatitis. The lesion was excised and sent for histopathologic evaluation with the clinical differential diagnoses of nodular basal cell carcinoma, vascular tumor, hidrocystoma, and melanoma. Results: Hematoxylin-and-eosin stained, 4-μm-thick sections demonstrated diffuse mucin deposition with floating islands of tumoral cells and glandular/ductal formation. Staining with periodic acid-Schiff, periodic acid-Schiff-diastase, and mucicarmine confirmed mucin deposition. Immunoperoxidase stains were performed on formalin-fixed and paraffin-embedded tissue using the following antibodies and were positive for cytokeratin 7, mammaglobin, GATA3, GCDFP15, CA19.9, and synaptophysin. P63 was focally positive. TTF1 and chromogranin were negative. The morphologic and immunohistochemical findings were consistent with a diagnosis of mucinous adenocarcinoma. Systemic investigation for colon, breast, prostate, and pancreas malignancy did not find any primary source. In addition, a focal in situ component was identified showing surrounding P63-positive myoepithelial cells. Discussion/conclusion: Primary cutaneous mucinous carcinoma of the eyelid is a rare low-grade malignancy of slow growth with local destructive invasion and frequent recurrence. It most commonly presents in older males in their seventies. The head and neck skin is the most common site with approximately half of case reports being from the eyelids. Because they can occur as a primary lesion or a metastatic lesion, the diagnosis of mucinous carcinoma requires further investigation to rule out metastatic carcinoma from other body sites, such as breast, colon, prostate, and pancreas. Primary mucinous carcinoma lesions are believed to arise from the apocrine sweat glands (rather than eccrine) but have been given the misnomer in the past of mucinous eccrine carcinoma. Apocrine sweat glands on the eyelids are more commonly located in the skin near the canthal angles and near the eyebrows. Given the potential concerns for morbidity, local invasion, and recurrence, management with MOHS surgery has been recommended. The presence of an in situ component with myoepithelial staining for P63 may help differentiate primary cutaneous mucinous carcinoma from secondary metastatic tumors. It is prudent for dermatologists to include this rare entity in the differential diagnoses and manage the patient appropriately.