Eccrine Porocarcinoma Presenting As Ulcerated Exophytic Mass.

摘要

Background: Eccrine porocarcinoma is a rare malignant neoplasm of the eccrine sweat gland associated with a high recurrence rate and poor response to therapy.Materials and Method: A report of malignant appendage tumours diagnosed over a 12months period (August 2007- July 2008). Histology slides stained routinely with Haematoxylin & Eosin were reviewed. Patients’ biodata and clinical information were obtained from the medical records.Results: Three malignant eccrine poroma were studied. There were 2 females and 1 male aged 38, 35 and 21 years. Clinical presentations were ulcerated exophytic lesion to polypoid circumscribed swellings. The sites of occurrence were the scalp and trunk. Tissue histology showed nests of large oval to spindle to polygonal tumour cells forming occasional tubule containing eosinophilic globules and separated by fibrous septa. Conclusion: Eccrine porocarcinoma should be considered in patients with exophytic tumours of the skin. A high index of suspicion, proper histologic interpretation with ancillary immunohistochemical studies will confirm diagnosis. Introduction Eccrine porocarcinoma is a rare malignant sweat gland tumour that typically arises from the terminal cells of the intraepithelial portion of the eccrine duct.1 It was first described by Pinkus and Mehreghan2 in 1963, as ‘epidermotropic eccrine carcinoma’, later in 1969, Mishima and Morioka3 introduced the term ‘eccrine porocarcinoma’. The causation is poorly understood, however it may arise de novo or as a malignant transformation of an eccrine poroma4. It has female preponderance, propensity for older age group, although it can be found in young adolescents and middle age. Patients and Methods Three patients had confirmed histological diagnosis of eccrine porocarcinoma at the Histopathology Unit, Federal Medical Centre, Lokoja, Kogi State, in the period August 2007 – July 2008. Their tissue biopsies were fixed in 10% formalin, embedded in wax and histological sections on slides were stained with Haematoxylin and Eosin (H&E). The histological and clinical details of the three patients are presented. Results There were two females (35yrs &38yrs) and one male (21years). The mean age is 31.3 years. They presented with progressively increasing masses/lesions localized on the left upper outer quadrant of the breast, scalp and right areolar of the breast respectively. Lesion had been presented for 6months to 2years. Clinically, the two females had ulcerated exophytic nodular ulcers on the scalp and upper outer quadrant of left breast respectively, while the male had an ulcerated polypoid mass on the areolar of right breast. They had a provisional diagnosis of squamous cell carcinoma and squamous Papilloma respectively. They all had incisional biopsies for tissue histologic diagnosis. We received ulcerated exophytic masses whose measurement ranges from 5.5x4.5x3.5cm to 4.4x3.8x2.8 to 3.5x2.8x1.7cm respectively.Histology of tissue biopsies showed sheets, nests, cribriform and large lobules of oval to spindle to polygonal tumour cells forming discrete tubules containing eosinophilic globules. The cells had moderately pleomorphic hyperchromatic to vesicular nuclei and amphophilic cytoplasm. They were diagnosed as eccrine porocarcinoma.