Rare Case of Malignant Melanoma of Lacrimal Sac

Presentation A 60 year old female presented to our clinic in July 2015 with complaints of left eye epiphora, and painless gradually increasing mass in the medial canthal area for 4 months. Probing revealed hard stop. At the time the mass was above the MCT and appeared separate from lacrimal sac. She was advised biopsy, but was lost to follow-up, only to present 6months later with a massive increase in the size of mass. There was no history of bloody discharge. On Examination, both eyes had senile cataract with BCVA of 6/24 in Right eye and absent light perception in left eye. A single, irregular, diffuse, firm mass was present in the medial canthal area of left eye, measuring approximately 2.5cmX2.5cm in size, with 3mm horizontal dystopia and blackish skin pigmentation. It involved the medial part of both upper and lower lid, lacrimal sac and canaliculi. It was non tender, immobile, with no surface ulcerations or pulsations. Excessive watering was present in the left eye, syringing could not be done since puncta were not visualized. There were no other swellings, no lymphadenopathy, and no history of significant weight loss. Hematological investigations were normal. Neuroimaging revealed a well-defined heterogenously enhancing solid lesion in the region of medial canthus of Left eye, about 2.3X2.8X1.7cm, involving the extraconal space, causing scalloping and widening of Left lacrimal fossa and NLD, and mild lateral displacement of the globe. Incisional biopsy showed tumor tissue composed of clusters of malignant cells-pleomorphic with high nuclear-cytoplasmic ratio, vesicular nuclei and prominent eosinophillic macronuclei. Foci of melanin pigment deposition were seen, leading to a diagnosis of malignant melanoma of the lacrimal sac. Metastatic work-up revealed lytic lesions in left frontal and right parietal skull bones and fibronodular opacities in upper and middle lobes of right lung, alongwith mediastinal lymphadenopathy. Hence the final staging was T4aN0M1c. No surgical treatment was planned and instead patient was referred for palliative systemic chemotherapy and radiotherapy. Discussion Malignant melanoma is a malignancy of the pigmentproducing melanocytes. It usually affects the skin and rarely