Phellinus tropicalis abscesses in a patient with chronic granulomatous disease

Abstract

Chronic Granulomatous Disease (CGD), caused by genetic defects in components of the phagocyte NADPH oxidase pathway, leads to recurrent life-threatening bacterial and invasive fungal infections. While a number of unique pathogens have been associated with this disease, the causative organisms may be difficult to identify. Here, we present a 24 year old male with known X-linked CGD who concurrently developed a cervical abscess and an abscess in the subcutaneous tissues of the right hip, both of which were surgically drained. Cultures failed to identify any organisms. He was treated empirically with ertapenem but the hip abscess recurred at the original site and in contiguous dependent areas in the posterior thigh and knee. A filamentous organism was observed microscopically, initially considered a contaminant, but on culture yielded a mold growth, identified as Phellinus tropicalis (synonym: Inonotus tropicalis) based on phenotypic and molecular methods. This is the third case report of human infection with P. tropicalis, all in subjects with CGD. The patient was treated with voriconazole with resolution of his symptoms.

Fig. 1

a, b CT neck with contrast showing retropharyngeal fluid and edema (black arrow) within the oropharynx and hypopharynx without discrete abscess, bilateral cervical lymphadenopathy and mediastinal lymphadenopathy. c, d CT neck with contrast showing resolution of inflammatory changes, a lobulated abscess (27 mm in greatest diameter) in the region of the previously noted edema (black arrow). There was swelling of the left aryepiglottic fold and airway compromise (white arrow). Lymphadenopathy was unchanged. e, f MRI of hip with contrast of hip. STIR (short t1 inversion recovery) axial (e) and coronal (f) images show a STIR signal bright lesion within the lateral soft tissues of the right hip which demonstrates peripheral irregular enhancement (black arrows), likely representing an abscess (7.1 cm×12.9 cm×8.8 cm). Additional smaller lesions were seen (black arrows). g CT with contrast of bilateral lower extremities (g) coronal and (h) axial images showing multiple (at least 4) oval low-attenuation lesions with surrounding rim enhancement in the right posterior thigh muscles, consistent with posterior muscle group abscesses (black arrows). The largest collection was 5.2 cm× 10.5 cm×1.9 cm in size

Fig. 2

a Photomicrograph of lactophenol blue stained hyphae showing a smooth-walled hyaline mold of Phellinus tropicalis. b Phellinus tropicalis growth on Sabouraud dextrose agar: the growth of P tropicalis at 14-days post incubation at different temperatures. The morphology on obverse (i, iii, v) and on reverse (ii, iv, vi) is shown. Maximal pigment production is seen at 30 ° C. Themorphology is typical of a basidiomycete