Histoplasma duboisii of the femoral bone

Abstract

Histoplasmosis due to Histoplasma duboisii is an emerging AIDS-defining opportunistic infection in HIV positive seen predominantly on the African continent between the Tropics of Cancer and Capricorn. Histoplasma duboisii is an invasive fungal organism with tropism for lymph nodes, skin and bones. The infection occurs more in patients with a CD4 count <50/mm³ and is usually dissemnnated Histoplasmosis due to Histoplasma duboisii is an emerging AIDS-defining opportunistic infection in HIV positive seen predominantly on the African continent between the Tropics of Cancer and Capricorn. Histoplasma duboisii is an invasive fungal organism with tropism for lymph nodes, skin and bones. The infection occurs more in patients with a CD4 count <50/mm³ and is usually disseminated. Literature reports of its occurrence in HIV negative patients are scanty. We report a case of histoplasma dubiosii infection of the left femur in a 9 year old HIV negative Nigerian with swelling in the left thigh of 5 months duration. Oral antibiotics and analgesics were prescribed for the patient with satisfactory clinical outcome. To our knowledge, this is the first reported case in an immunocompetent child in Nigeria. Literature reports of its occurrence in HIV negative patients are scanty. We report a case of histoplasma dubiosii infection of the left femur in a 9 year old HIV negative Nigerian with swelling in the left thigh of 5 months duration. Oral antibiotics and analgesics were prescribed for the patient with satisfactory clinical outcome. To our knowledge, this is the first reported case in an immunocompetent child in Nigeria.

Keywords: Histoplasma duboisii; femoral bone; immunocompetence.

Figure 1

Plain radiograph of a 9-year-old boy with a painful left thigh swelling of 5-month duration. There is a reduction in the corticomedullary differentiation of the distal diametaphysis of the femur with soft-tissue swelling, preserved fat plane, spiculated periosteal reaction, and cortical erosion

Figure 2

Computed tomography scan report showed a reduced corticomedullary differentiation in the distal diametaphysis of the femur with a sunray periosteal reaction with cortical erosion and a hypodense avascular soft-tissue mass in the distal femur

Figure 3

This photomicrograph shows numerous multinucleated giant cells containing cytoplasmic round-to-oval fungal bodies. Furthermore, it observes numerous histiocytes with eccentrically located nuclei with cytoplasmic vacuoles containing oval-shaped fungal bodies of Histoplasma duboisii. Similar bodies were also seen in the giant cells and also extracellularly (H and E, ×300)

Figure 4

The fungal bodies are highlighted in this periodic acid–Schiff-stained section (×600)

Figure 5

Six months after treatment with antifungal drugs