Lupus vulgaris complicated by metastatic squamous cell carcinoma.

A 47-year-old Bedouin man presented with an ulcerated nodule of several months' duration on the nape of the neck. The nodule developed on an asymptomatic, slowly growing plaque which appeared during childhood. Physical examination revealed two erythematous plaques covering the posterior and right lateral aspects of the neck. The border of the plaques was soft, circinate, with a reddish-brown color, while the center was slightly erythematous and atrophic. An ulcerated nodule measuring 2 cm was seen on one of the plaques. Physical examination was unremarkable with no lymphadenopathy. Laboratory tests, including complete blood cell count, erythrocyte sedimentation rate (ESR), and routine chemistry tests, were all within normal limits. Chest X-ray showed a small calcified perihilar lymph node. The Mantoux test was positive with erythema and induration of 15 mm after 48 h. Biopsy from a plaque showed extensive diffuse granulomatous infiltration throughout the dermis with epithelioid and Langhans giant cells surrounded by mononuclear inflammatory cells. No caseation necrosis was present. Ziehl-Neelsen, periodic acid-Schiff (PAS), and Giemsa stains were negative. Polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis and atypical mycobacteria from a skin sample was also negative. Fresh tissue cultures yielded M. tuberculosis after 6 weeks. A biopsy specimen from the ulcerated nodule demonstrated islands of atypical malignant squamous cells invading the dermis, which were compatible with moderately differentiated squamous cell carcinoma (SCC). The ulcerated nodule was completely excised, and treatment for tuberculosis was initiated with a combination of isoniazid, rifampicin, and pyrazinamide. Within 3 months of therapy, the patient's lesions resolved, leaving only slightly atrophic hypopigmented scars. A month after the treatment's initiation, an enlarged cervical lymph node was noted showing metastatic SCC on histologic examination. The patient underwent neck dissection and radiation therapy without evidence of any further metastases.