Extrapulmonary Pneumocystis carinii infection in an AIDS patient: a case report

Extrapulmonary Pneumocystis carinii (EPC) infection is an uncommon condition, regardless of HIV status, and can occur as a complication of P carinii pneumonia (PCP). However, PCP is the most common severe opportunistic infection in patients with AIDS. The incidence of EPC is variable, and in HIV-1-infected individuals it has been estimated to be 0.06-2.5%.

A case of generalized lymphadenopathy was referred to us for fine needle aspiration cytology (FNAC). The patient was a 9-year-old boy who had a toxic facies and manifested multiple skin lesions all over the body. Fever was present during the examination. HIV status was confirmed from the history and test report. FNAC was done from a cervical lymph node and smears stained with hematoxylin-eosin and with Giemsa and Papanicolaou stain. The presence of P carinii was suspected in Giemsa- and hematoxylin-eosin-stained smears, and silver methenamine stain was used to confirm the diagnosis. Fungal spores were seen as small, spherical cysts of variable sizes, more or less the size of erythrocytes. The diagnosis was thus established as EPC infection.

Lymph node involvement is the most common site of pneumocystosis in AIDS patients. Fine needle aspiration diagnosis of EPC infection is a possibility in such cases with lymphadenopathy and must be included in the differential diagnosis of lymph node swellings in AIDS.