Amelanotic Melanoma Arising in Filarial Leg: A Report of a Rare Case

Abstract

A 60-year-old male farmer had bilateral filarial lymphoedema of both legs for last 30 years. He presented with the complaint of foul smelling multiple ulcero proliferative lesions encircling the right ankle region from three months duration. To start with there was a small nodular growth in the same site for one and half years back, which was gradually increasing in size and ulcerated with serosanguinous discharge. It was managed conservatively in another hospital with dressing and oral antibiotics. The lesion progressed to a large fungating and multinodular mass which was foul smelling. Some of the nodules showed surface ulceration with oozing.On physical examination both limbs were markedly oedematous but oedema was more in the right lower limb, skin of both legs were markedly thickened with a circumferential nodular mass measuring around 25 cm located above the right ankle region [Table/ Fig-1a-c].Inguinal lymphnodes of both sides were not palpable. Laboratory investigations revealed peripheral eosinophilia with absolute eosinophilic count of 1.89x103 cells per microliter, increased Erythrocyte Sedimentation Rate (ESR) (86 mm in first hour) and normal fasting blood sugar (86 mg/dl). The serological tests for HBsAg, HCV and HIV were negative. Liver function test was normal. No microfilariae was found on peripheral smear. Fluorescent antibody test for Wuchereria bancrofti and Brugia malayi antigens were negative. Culture report from the wound discharge grew Edwardsiella and Enterococcus, which were sensitive to Cefixime, Ceftazidime, Levofloxacin, Ciprofloxacin and Tazobactam-Piperacillin. Chest X-ray was normal. X-ray of right lower limb showed no involvement of underlying bone. Computed Tomography (CT) scan of whole body and abdomen showed no distant metastasis [Table/ Fig-2a-d]. He had a family history of filariasis of his mother and belonged to an endemic region of filariasis. The patient had undergone surgery for hydrocele which was of filarial origin 10 years back for which no details were available. Incisional biopsy from the circumferential growth was obtained.Histopathological study revealed islands, clusters and small nests of tumour cells with round to oval plump nuclei and conspicuous nucleoli arising from the basal layer of epidermis and infiltrating the dermal papillae, papillary dermis and reticular dermis with variegated morphology [Table/ Fig-3a]. In few areas the tumour cells were spindle shaped resembling a sarcoma [Table/ Fig-3b]. Prominent interspersed vascular channels lined by atypical cells of both spindle and epithelioid cells and foci with clear cell change were seen [Table /Fig-3c,d]. The arrangement of tumour cells varies from papillary to organoid, nesting and alveolar patterns [ Based on histopathology and immunohistochemical markers, a diagnosis of amelanotic melanoma with a proliferative index (MIB1) of 4 % was made. Clark's level was IV and TNM stage was IIC. After consideration of all the available treatment modalities, wide local excision of the tumour was done followed by ski...

Unsuspected amelanotic melanoma in an elephantiasis foot

“…who also reported a similar case in a 60-year-old farmer. [ 3 ] In view of the new therapeutic modalities which could be of use in KIT mutated complete type of acral amelanotic melanoma, its recognition is important.…”