Primary Cutaneous Mucinous Carcinoma of the Lower Eyelid: First Reported Case From Pakistan

Abstract

Primary Cutaneous Mucinous Carcinoma (PCMC) is an extremely rare malignancy arising from sweat glands with fewer than 0.1 cases per million population. PCMC predominantly affects the head and neck region, with the eyelid being the most common site. Despite its indolent progression, PCMC has a significant local recurrence rate following excision. To our knowledge, this represents the first documented case of eyelid PCMC from Pakistan. A 65-year-old male presented with a gradually enlarging, asymptomatic, reddish nodular lesion on the left lower eyelid that had developed over 5 years. Initial excisional biopsy revealed characteristic histopathological features of mucinous carcinoma. Comprehensive systemic workup (MRI, CT scans, and tumor markers) excluded metastatic disease or secondary mucinous carcinoma. The patient underwent definitive treatment with pentagonal full-thickness eyelid resection using 2 mm margins. Histopathological examination of the excision specimen showed no viable tumor cells with all margins clear. At 6-month follow-up, the patient demonstrated excellent functional and esthetic outcomes with no evidence of recurrence. This case contributes several clinically relevant insights beyond geographic documentation: successful oncological clearance using conservative 2 mm margins in an anatomically sensitive location, validation that tissue-sparing surgical approaches can achieve excellent functional outcomes while maintaining oncological adequacy, and expansion of the limited global case series. Recent SEER database analysis shows regional disease rates of 10.5%, emphasizing the importance of clinical surveillance despite the typically indolent course. This report demonstrates the effectiveness of conservative surgical margins in anatomically sensitive regions and emphasizes the need for increased regional awareness of this rare entity.