A child with an extensive indurated subcutaneous plaque

Dear Editor, A seven-year-old boy presented with an insidious onset, slowly progressive, painless mass initially noted over the left arm and later progressed to involve proximally over the chest and upper back for two years. He underwent surgical excision when the lesion was 2 × 2 cm2, 1.5 years back with a recurrence of the lesion. The parents did not reveal any history of major trauma or surgeries. Examination revealed a solitary, subcutaneous, painless, indurated noduloplaque measuring 15 × 20 cm2 with a finger insinuation test positive, with fixity to the overlying skin and mobile over the musculoskeletal plane [Figure 1a and b]. A large irregular to geographic atrophic scar was noted over the left arm. No regional lymphadenopathy or limitation in joint movements. Histopathology demonstrates multiple granulomatous foci revealing splender Hoeppli phenomena, surrounding the basidiobolus fungal hyphae, broad, pauci septate, surrounded by eosinophils, neutrophils, epithelioid histiocytes, and numerous multinucleated giant cells. Periodic acid Schiff and Gomori methanamine silver stain highlights the pauciseptate fungal hyphae [Figure 2a-d]. With the diagnosis of basidiobolomycosis, the child was administered itraconzole 10 mg/kg/day with a saturated solution of potassium iodide (SSKI) 20 drops thrice daily, with 40% resolution after one month and near complete resolution at two months. Later, itraconazole was continued for three months postresolution [Supplementary Figure 1a and b].Figure 1: (a) Ill-defined nontender extensive indurated subcutaneous swelling measuring 15 × 20 cm2. (b) Demonstrating positive finger insinuation testFigure 2: (a)Histopathy depicts multiple granulomatous foci with splendor Hoeppli phenomenon [H and E, 50×]. (b) Histopathology reveals basidiobolus fungal hyphae, broad, pauci septate, surrounded by eosinophils, neutrophils, epithelioid histiocytes, and numerous multinucleated giant cells [H and E, 400×]. (c) Periodic acid Schiff highlights the pauciseptate fungal hyphae [H and E, 400×]. (d) Gomori methanamine silver stain highlights the pauciseptate fungal hyphae [H and E, 400×]Supplementary Figure 1: (a) Partial resolution after one month of follow-up with itraconazole and SSKI. (b) Near complete resolution after two months of follow-up with itraconazole and SSKIEntomopthoromycosis is a chronic subcutaneous fungal infection seen in both immunocompetent and immunocompromised individuals in tropical and subtropical regions. It encompasses conidiobolus and basidiobolus.[1] Basidiobolomycosis is characterized by a bathing suit distribution of swelling, predominantly in children and males. It is caused by Basidiobolus ranarum found saprophytically in dead decaying vegetation and intestinal contents of several species of amphibians, for example, frogs, toads, and reptiles.[2] Clinically, it presents as a painless, well-circumscribed, woody hard induration with overlying skin freely mobile from underlying swelling, with a positive finger insinuation test. It may involve the musculoskeletal and gastrointestinal systems. On potassium hydroxide mount, broad (diameter, 8–15 μm) hyphae, the large number of asexual spores were characterized by the presence of a hyphal tag, some of which were characterized by cleavage formation to produce meristospores.[3] On Saboraud’s dextrose agar mount, at 30°C, rapid growth with a musty odor, rugose and smooth, appearing yellowish gray on the surface and pale reverse, and has a waxy texture. As growth progresses, satellite colonies can be appreciated due to the forced ejection of sporangioles (ballistospores).[2,3] Spontaneous resolution may occur. Therapeutic options include the saturated salt solution of potassium iodide and oral itraconazole, and in resistant cases, voriconazole has also been tried with variable response.[3] The very first case of subcutaneous phycomycosis was reported in Indonesia in 1956 by Lie Kian Joe et al.[4] Following this, a series of 31 cases was published in 1964 from Uganda.[2] 55% of the total cases were under nine years of age, with a male predominance. They described the “feel” of the lesion as if a distinct region of skin and subcutaneous tissue appeared to have become coagulated, seemingly due to an electric current. Constitutional features were either absent or minimal. They started patients on oral potassium iodide and noticed marked regression/disappearance of lesions.[5] A similar case was reported by Prasad et al.[6] A child of 1.5 years of age with a swelling on the anterior chest wall had suspected phycomycosis with histopathological evidence of phycomycosis, but were unable to isolate the organism. Another case of a three-year-old girl reported in Maharashtra by Anand et al.[7] presented as a painless swelling over the anterior chest. The diagnosis was further supported by histopathological evidence and mycological isolates of B. ranarum. Lesions rapidly resolved with oral itraconazole over a period of three weeks. Our case highlights the extensive subcutaneous basidiobolomycosis and therapeutic response to itraconazole and saturated solution of potassium iodide. Author contributions SKG: Concepts, manuscript preparation, and manuscript editing. DB: Concepts, literature search, data analysis, and manuscript preparation. PV: Design, manuscript preparation, and manuscript review. SM: Concepts, design, manuscript preparation, manuscript editing, manuscript review, and guarantor. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflict of interest There are no conflicts of interest.