LAUSR

CASE A34-year-old female presented at a hospital in San Antonio with worsening of chronic diffuse abdominal pain and subjective fevers. The patient presented in mild distress without a history of weight loss, loss of appetite, abdominal trauma, prior radiation, or obstruction. An abdominal mass was noticed 16 years prior at the time of an induced abortion but did not receive any intervention. She relocated from Ghana 2 months prior to presentation with a history of exposure to an unclean water source and goat husbandry. Upon physical examination, she was febrile at 100.5°F and tachycardic. Her abdomen was soft, nondistended, and tender to palpation in the left lower quadrant without rebound. Computed tomography (CT) of the abdomen and pelvis showed bulky dystrophic calcifications within the root of the mesentery, measuring up to 5.1 by 7 by 5.6 cm (Fig. 1A). She was empirically treated with vancomycin and piperacillin-tazobactam. CT-guided biopsy of the mass was performed. A Diff-Quik-stained touch preparation of the core biopsy sample showed multiple variably stained budding yeast cells ranging from 2 mm to 10 mm (Fig. 1B). The core biopsy on histopathologic examination showed negatively stained broad-based budding yeast cells on hematoxylin and eosin-stained sections (Fig. 1C). The Grocott-Gomori methenamine silver (GMS) stain highlighted round to oval-shaped yeast cells with some broad-based budding (Fig. 1D). The Gram stain and calcofluor white stain identified budding yeast cells. Fungal cultures grew white colonies on Sabouraud dextrose agar within 2 weeks of incubation (Fig. 2A). A lactophenol cotton blue preparation of the culture growth showed round tuberculate macroconidia consistent with Histoplasma (Fig. 2B). Histoplasma capsulatum was detected by rapid DNA probe test with the nucleic acid hybridization technique (Histoplasma Hologic Accuprobe test) performed on the culture isolate. The susceptibility test was performed by broth microdilution as per Clinical and Laboratory Standards Institute (CLSI) standard M38 (1). The results were as follows: isavuconazole MIC, 0.06 mg/mL; itraconazole MIC #0.03 mg/mL; posaconazole MIC, #0.03 mg/mL; voriconazole MIC, #0.03 mg/mL. DNA sequencing and phylogenetic analysis of the a-tubulin-1 and the ADP-ribosylation factor genes were performed to identify the species, which was confirmed to be Histoplasma duboisii. The patient was found not to be a surgical candidate due to the proximity of the mesenteric mass to major vessels. Itraconazole was initiated to treat the mass medically. Due to adverse effects experienced and attributed to itraconazole, including worsening of abdominal pain, dyspepsia, photophobia, nausea, tinnitus, nonexertional chest pain, and palpitations which persisted even after the dose was lowered from 200 mg every 12 h to 100 mg every 12 h, therapy was changed to posaconazole after Editor Carey-Ann D. Burnham, Pattern Bioscience Copyright © 2022 American Society for Microbiology. All Rights Reserved. Address correspondence to Apeksha N. Agarwal, [email protected]. *Present address: Daniel D. Mais, Department of Pathology, University of Louisville, Louisville, Kentucky, USA. The authors declare no conflict of interest. For answers to the self-assessment questions and take-home points, see https://doi.org/10 .1128/JCM.01202-21 in this issue. Published 20 July 2022