An unusual collision tumour masquerading as a basal cell carcinoma on the nose.

When two or more cutaneous tumours coexist in a single lesion, it is known as a cutaneous collision or contiguous tumour. Various combinations of collisions have been described. Collision tumours often have misleading clinical and histological presentations, and can be a diagnostic challenge. Chondroid syringomas are mixed cutaneous tumours of dual origin, and like collision tumours, are often confused with the more commonly seen cutaneous lesions. As chondroid syringomas are rare, their involvement in collision tumours is an even more peculiar occurrence. We report an unusual case of a cutaneous collision tumour on the nose involving an intradermal naevus and chondroid syringoma. To the best of our knowledge, this is the first time such a combination is reported.

Multiple leiomyoma as a possible sign of aggressive renal cancer.

A 53-year-old Chinese man presented with a history of painful lesions on the chest of 20 years' duration. He experienced sharp pain especially on touching and after spicy food. The lesions were stable with no increase in size or number. He was otherwise well. There was no significant family history. Physical examination revealed multiple, grouped, pink papules on the left chest, extending to the right back in a segmental distribution, each measuring 2-5 mm (Figs 1 and 2). They appeared pearly and keloid-like, and had a firm consistency. A punch biopsy specimen was obtained and sent for histopathologic examination (Figs 3 and 4). This revealed a circumscribed, nonencapsulated tumor with a Grenz zone below the epidermis. It was composed of interlacing fascicles of bland spindle cells with elongated nuclei and blunt ends, typical of a cutaneous leiomyoma. The patient subsequently underwent computed tomography of the abdomen, which did not show any renal or abdominal masses.