Primary extensive perianal cutaneous tuberculosis: A challenging diagnosis. Case report and a review of the literature.

Rationale: Perianal tuberculosis is extremely rare without previous or active pulmonary infection. Ulcerative skin lesion is a rare presentation of extrapulmonary tuberculosis in the oral, perianal, or genital mucosa and the adjacent skin.

Case Report: A 71-year-old woman complained of pain during evacuation and fecal incontinence for two years. There was an ulcerated lesion in the perianal and intergluteal region and perianal fistulous tracts. A polymerase chain reaction test on blood and biopsies of perianal ulcers, perianal fistula, and the intergluteal area was positive for Mycobacterium tuberculosis. The pathological examination revealed a chronic epithelioid granulomatous inflammatory process with the presence of multinucleated giant cells. After the end of the tuberculosis drug regimen, there was marked improvement in the patient's clinical condition.

Conclusion: Even in the absence of an identifiable primary focus, tuberculosis should be considered in the differential diagnosis of ulcerative and fistulous lesions of the perianal area.