Eyelid Apocrine Hidrocystomas in a Cat

Background: Eyelid apocrine hidrocystoma (AH) is a benign cystic lesion originating from the glands of Moll. These eyelid lesions are rare in cats and there are few cases reported in the literature. The aetiopathogenesis of AH is unknown and the lesion has been interpreted either as proliferative adenomatous tumour or as retention cyst. Defnitive diagnosisrequires biopsy with microscopic examination. Treatment options for eyelid AH include surgical excision, drainage through aspiration, cryosurgery with liquid nitrogen and chemical ablation. The aim is to report a case of bilateral multiple AH of the eyelids in a cat that was successfully treated with surgical excision.Case: A 5-year-old male Himalayan cat was referred to the Ophthalmology Section in the Veterinary Clinics Hospital of the Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil with a history of pigmented masses in both eyes that had been progressively enlarging over a 1-year period. Ophthalmic examination revealed two cysts on themedial canthus at the eyelid margin in both eyes. In the left eye was observed mild blepharospasm and lacrimation. Cysts were soft, smooth, round and flled with a dark brownish pigment. The remainder of the ophthalmic examination was unremarkable. Surgical excision of the cysts was indicated with a safety margin. The surgical procedure was performedunder inhalation anaesthesia using an operating microscope. A V-shaped, full-thickness excision of the eyelid containing the cyst was performed. The eyelids were closed with two layers of sutures. No complications were noted during surgery. Microscopic examination revealed cystic dilatation of the sweat glands with a large amount of eosinophilic secretion. EyelidAH was diagnosed based on the results to confrm the diagnosis. The cat recovered and was discharged the following day. The postoperative treatment involved the administration of tramadol (2 mg/kg, PO, q 12 h) daily for 3 days. After surgery, the cat had no signs of ocular discomfort. After three years, no recurrence has been observed.Discussion: AH is a benign tumour derived from Moll’s glands. The exact aetiology of AH is unknown. A breed-specifc predisposition among Persian cats has been suggested. In the present case, the ophthalmic examination revealed periocular masses brownish to black, round, soft, and fluid-flled. Multiple pigmented nodules involving the skin of the lower eyelids were observed. In the current case, the cat was of the Himalayan breed and was 5 years old with multiple AH in both eyelids. In terms of clinical features, this case was similar to previous ones reporting eyelid AH in cats. Normally, a defnitive diagnosis is confrmed through histopathology after excisional biopsy. In the current case, diagnose was made on the basis of the clinical fndings, history, and results of histological examination. Treatment options for eyelid AH include surgical excision, aspiration, cryosurgery and chemical ablation with trichloroacetic acid. Surgical removal of the cysts was performed in the current case. Histopathologic examination revealed cystic dilatation of the sweat gland with large amount of eosinophilic secretion. The sutures were removed one week after surgery. Periodic evaluations were conducted and there were no signs of recurrence after three years. In the present case, surgical excision was effective in the treatment of eyelid AH in a cat.Keywords: lid, cystic adenomas, feline