Malignant Hidradenoma of the Medial Canthus and Orbit

Abstract

Abstract: : Purpose: Malignant hidradenoma is a very rare tumor of eccrine sweat gland origin. We believe this is the first report of malignant hidradenoma of the medial canthus with orbital and intracranial extension. Methods: A 70–year–old Caucasian woman presented with a 6 month history of right–sided epiphora and a 3 month history of an enlarging right medial canthal mass. Computed tomography and magnetic resonance imaging of the head and orbit revealed a right medial orbital tumor with intracranial extension and involvement of the paranasal sinuses. Intranasal biopsy showed malignant hidradenoma and the patient was referred for further management. Results: External examination revealed erythema of the right medial canthus. An underlying indurated, nodular mass was present. Gross telecanthus was noted and Hertel exophthalmometry showed 4 mm of right proptosis. Irrigation confirmed complete stenosis of the right nasolacrimal system. Right medial orbitotomy, anterior ethmoidectomy, and frontal craniotomy were performed with biopsy and removal of gross tumor. Histopathology showed a malignant clear cell hidradenoma with sebaceous differentiation. CEA, PAS, pancytokeratin, CK7, CK20, mucin, S100, EGFR 2+ and Her2/neu studies supported this interpretation. Angiolymphatic invasion was present. The patient’s immediate post–operative course was uncomplicated. Erythema and edema of the right medial canthus and several indurated, nodular masses were noted just prior to the initiation of radiotherapy. The patient was started on radiation therapy and adjuvant chemotherapy with low–dose carboplatin and Taxol. Conclusions: Malignant hidradenoma is a very unusual tumor that we believe has never been reported in the medial canthus with orbital and intracranial extension. We describe a patient with a malignant hidradenoma that initially presented with epiphora secondary to nasolacrimal duct obstruction. A medial canthal tumor later became apparent. Imaging studies revealed a right medial orbital mass with intracranial extension and involvement of the paranasal sinuses. Subsequent biopsy and tumor resection confirmed malignant hidradenoma. Clinical recurrence was noted 2 weeks after tumor resection, just prior to the initiation of radiation and chemotherapy. Awareness of this aggressive, invasive tumor is important.

Keywords: oncology • eyelid • orbit