Case Presentation
The patient is a 14 years old boy who presented with signs of epistaxis and fatigue from three months ago. Laboratory data showed severe pancytopenia. Considering the risk of spontaneous hemorrhage, he was immediately transferred to the tertiary center for comprehensive care. Subsequent investigations through bone marrow biopsy and flow cytometry were consistent with the diagnosis of acute myeloid leukemia (AML) M3 type. The patient received appropriate therapy first with daunorubicin and ATRA and later with Arsenic trioxide. He then presented to the hospital three months later with numerous bulging subcutaneous masses on his buttocks, thighs, calves, and plantar surface of his feet. Similar lesions, albeit fewer, were observed in the back and upper extremities.
Ultrasonography was done, and multiple thick-walled cystic lesions containing some internal echogenic material were seen in the subcutaneous tissue and within muscular compartments of lower extremities with peripheral vascularity on Doppler ultrasound, suggestive of abscess formation. Multiple target-shaped and hypoechoic lesions were also observed in the liver and spleen (Figure 1). Magnetic resonance imaging(MRI) of the lower extremities was performed and showed numerous iso- to hyper-signal on T1 and hyper-signal on T2-weighted oval lesions with hypo-signal rim within different muscles of the lower extremities and also in subcutaneous tissue. The almost diffuse hypo-signal intensity of bone marrow of the bilateral tibia and fibula on the T1-weighted sequence was also seen due to leukemic infiltration (Figure 2). Subsequent needle aspiration of muscular lesions under ultrasound guidance was performed, and cytopathology and culture reports were consistent with abscess formation due to Candida Albicans (Figure 3). Brain MRI also was performed and showed subdural hematoma in the right frontoparietal convexity(due to low platelet level). A chest x-ray didn’t show any abnormality.
So, antifungal therapy with intravenous Amphotericin-B was given to him for two weeks and then step-down therapy with oral fluconazole was started. After three months of anti-fungal treatment with oral fluconazole along with chemotherapy, the patient was evaluated again clinically and by imaging modalities including ultrasonography and MRI. He felt generally well and bulging subcutaneous lesions in the back, upper extremities, and thighs disappeared or shrinkage, compared with pre-treatment physical examination. Although MRI showed almost complete resolution of bone marrow leukemic infiltration, many of the leg abscesses still persisted without change, and some of the lesions coalesced together. Fortunately, Some leg abscesses changed to non-enhancing signal void small foci in post-treatment MRI due to calcification, which was confirmed on the targeted ultrasound. Also, the complete resolution of hepatic lesions and calcification of splenic lesions was seen in ultrasonography (Figure 4).
Due to the persistence of abscess on the buttocks and plantar surface of the feet, which impaired the patient’s walking and sitting ability, surgical incision was also performed. Post-surgical pathology was reported as granulation tissue with focal abscess formation with complete resolution of candida infection.