There are only a few cases of dermatomyositis associated with urological malignancy reported in the literature. We report on a patient who presented with dermatomyositis as an early and sole manifestation of prostatic adenocarcinoma. To our knowledge this is the first such case reported in the literature. CASE REPORT A 63-year-old man presented with an erythematous rash on the scalp, neck, upper chest, back, extensor aspect of the elbow and gluteal region. The patient also had purple plaques over the back of his hand. A clinical diagnosis of dermatomyositis was made despite the absence of muscle weakness. Autoantibody screen and thyroid function tests were normal. Biopsy of skin from the back of the hand showed infiltration of the basal layer of epidermis with lymphocytes, with upper dermal and perivascular mononuclear infiltrate. Mucin stains demonstrated an increased amount of acid mucin in the papillary and upper reticular dermis, confirming the diagnosis of dermatomyositis. The patient had no other symptoms, and screening for internal malignancy did not reveal any primary tumor. He was started on oral steroids, which resulted in marked improvement of the skin lesions. The patient was followed regularly, and 14 months after initial presentation he complained of urinary frequency, nocturia and poor flow. Digital rectal examination showed a moderately enlarged firm prostate with no nodules. Prostate specific antigen (PSA) was 100 g./l. Acute urinary retention subsequently developed, and transurethral prostatectomy was performed. Histological examination demonstrated prostatic adenocarcinoma (Gleason score 9). Hormonal ablative therapy with cyproterone acetate and goserelin was commenced. Staging computerized tomography revealed a 5 5 5 cm. prostate infiltrating the floor of the bladder, pelvic side wall and left side of the rectum. The seminal vesicles were involved with multiple enlarged lymph nodes measuring up to 2 cm. Bone scan showed metastases to the pelvis, spine and ribs. With hormonal ablative therapy PSA dropped to 4.3 g./l. and oral steroids were discontinued. Within a few months of starting treatment the skin lesions disappeared, with the exception of the plaques on the back of the hand. DISCUSSION
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