Metastatic tuberculous abscesses in an immunocompetent patient

Abstract

The decreased incidence of infectious diseases in developed countries may make their diagnosis difficult. Cutaneous tuberculosis is an example of this fact. A 44-year-old man presented with two painful abscesses on his lower extremities, which developed into chronic ulcers. A cutaneous biopsy revealed necrotizing granulomas in the dermis. Ziehl-Neelsen and periodic acid-Schiff stain were negative. Mantoux test was positive. Tc-99m scintigraphy showed increased uptake in the bone tissue of the left ankle and right tibiae, without direct relation to cutaneous lesions. Chest X-ray showed micronodular, apical, bilateral infiltrates, reduced volume of the right lung, and cavitation of the right superior lobe. Mycobacterium tuberculosis was grown from sputum and skin biopsy samples. Isoniazid, rifampin and pyrazinamide treatment for 2 months, followed by isoniazid and rifampin for 12 months, resulted in complete resolution. The clinical features of cutaneous tuberculosis in our patient were characteristic of tuberculous abscesses. Some uncommon findings, such as the low number of lesions, negative acid-fast resistant stains in cutaneous biopsy samples and his preserved general state of health, may be explained by a higher competence of the immune system than is usual in this clinical subset of disseminated tuberculosis. Cutaneous tuberculosis should be included in the differential diagnosis of cutaneous abscesses in immunocompetent patients.