Urine antigen-negative disseminated histoplasmosis mimicking post-transplant lymphoproliferative disorder

A 50-year-old woman with a history of kidney transplant presented with 2 days of abdominal pain after 6 months of recurrent streptococcal pharyngitis, fevers, weight loss and a new rash on her chest and back. Her examination was notable for a unilateral tonsillar exudate and 2-3 mm pink papules with a fine scale over her chest and back. CT of the abdomen and chest demonstrated several large lymph nodes, and laboratory investigation revealed new cytopenias and elevated transaminases. Urine antigen testing for Histoplasma capsulatum was negative, but a fungal complement fixation panel was reactive for Histoplasma antibodies. Skin biopsy revealed intracellular organisms consistent with H. capsulatum. She underwent treatment with liposomal amphotericin B but due to nephrotoxicity, drug interactions and worsening transaminitis, therapy was changed to itraconazole. The diagnosis and management of disseminated histoplasmosis presents multiple challenges, which are of particular importance in patients with a history of renal transplantation.