Candida parapsilosis bone marrow infection in an immunocompetent patient

Abstract

Background: We discuss a case of an immunocompetent patient who presented with fever and tachypnoea, found to have Candida parapsilosis bone marrow infection, cultured on bone marrow aspirate sample. Candida parapsilosis is an opportunistic yeast pathogen that typically affects immunocompromised individuals, or occurs in patients with apparent introduced source; neither of these factors were present for this case. Bone marrow aspirates and trephines are not regular investigations for fever; however they can be useful diagnostic aids as evidenced in this case.

Case report: An 83-year-old woman presenting with fevers and tachypnoea was being treated for a systemic bacterial infection, however was unresponsive to empirical antibiotic therapy. To exclude an occult malignancy, an 18-fluorodeoxyglucose positron emission tomography scan was conducted. Significant bone marrow uptake was noted, prompting a bone marrow aspirate and trephine to investigate for a hematological malignancy. While the trephine biopsy was benign, a culture of the aspirate grew Candida parapsilosis. Intravenous antifungal therapy was initiated; however, the patient did not improve despite targeted therapy likely due to delays in diagnosis, and was palliated.

Conclusion: Our case seeks to demonstrate a novel case whereby a bone marrow aspirate culture provided a conclusive diagnosis of invasive Candida parapsilosis bone marrow infection, and guided treatment in an immunocompetent patient. It is important for clinicians to consider invasive fungal infections in febrile patients regardless of immune status. Additionally, when performing a bone marrow aspirate and trephine on a febrile patient, we recommend including aspirate fungal cultures to investigate for an invasive fungal infection.

Keywords: Bone Marrow; Candida parapsilosis; Invasive Fungal Infections.

Fig. 1

PET scan showing diffuse uptake in the bone marrow of the patient. Areas of diffuse uptake indicated with arrows. PET, Positron Emission Tomography.

Fig. 2

Bone marrow examination findings: (A) bone marrow aspirate demonstrating hemophagocytosis with active phagocytic cells containing intact cells and cellular debris (x 400 magnification); (B) bone marrow trephine demonstrating hypercellularity with granulocytic hyperplasia and no excess of blasts, lymphocytes or granuloma formation (x 200 magnification); (C & D) bone marrow trephine immunohistochemistry with Grocott silver stain (x 100 magnification) revealed non-specific uptake only (positive control = black staining) and was negative with (E & F) Periodic acid-schiff stain also (x 100 magnification; positive control = bright pink staining).