Otic pneumocystosis in acquired immune deficiency syndrome.

AIDS-associated otic pneumocystosis is rare. Of 14 cases documented mainly as case reports up to now, only 1 has been reported in the surgical pathology literature. We report 6 males, mean age of 32.3 years, with external auditory canal masses and otorrhea. Two biopsies contained a predominance of granulation tissue with a mixed inflammatory cell infiltrate and elusive foci of foamy exudate. In contrast, 4 biopsies demonstrated conspicuous angiocentric mantles of stippled, foamy exudate. Fibrin was noted in intravascular, perivascular, and intervascular locations. One biopsy demonstrated bordering of the foamy exudate by a palisaded granulomatous reaction, with adjacent discrete giant cell-containing granulomas. Special stains confirmed trophozoites and cysts within the foamy exudate. Review of 2 initial "nondiagnostic" biopsies confirmed granulation tissue and necrotic debris in which Pneumocystis jiroveci was identified in focal foamy exudate. After the diagnosis of otic pneumocystosis, all patients were initiated on trimethoprim-sulfamethoxazole. One patient also had dapsone. Two patients succumbed to pulmonary tuberculosis and 2 were lost to follow-up. One patient with pneumocystis pneumonia did not return for follow-up after 6 weeks. One patient experienced complete resolution of the mass on medical therapy, and is disease free for 4 years. Heightened recognition of the characteristic foamy exudate in an unconventional location remains the gold standard in the timely diagnosis of this eminently treatable disease. In all patients, otic pneumocystosis served as the sentinel of underlying HIV infection and AIDS.