P383 ‘It's not Fungus, its Nocardia’—an elementary diagnostic challenge for draining sinus on abdominal wall (rare): a case report

POSTER SESSION 3, SEPTEMBER 23, 2022, 12:30 PM - 1:30 PM: INTRODUCTION: A rare finding of abdominal wall clinical presentation of persistent progressive tumefaction with draining sinus with no granules caused by Nocardia brasiliensis. METHODS: History: A 22-year-old presented to the Dermatology OPD with complaints of swelling and tenderness and discharging sinuses with no granules around the periumbilical region in the lower abdominal area for three years. His initial fine needle aspiration cytology specimen report was inconclusive. He received anti-Kochs treatment based on a positive Montoux test and family history from outside the hospital. Initially punch biopsy samples were sent for fungal processing to our laboratory which was inconclusive. Repeat pus aspirate and punch biopsy samples were subjected to conventional techniques. The sample was inoculated on Sabouraud's Dextrose agar, Brain heart Infusion agar, and Lowenstein-Jensen media. Direct Smear was subjected to Gram stain and Modified Zeihl Neelson stain with 1% Sulfuric acid as decoloriser. RESULTS: On Gram stain, Gram-positive filamentous bacilli against a background of pus cells in pus aspirate only (not in punch biopsy specimens). Modified Zeihl Neelson stain with 1% Sulfuric acid decoloriser was performed on all three samples. Beaded acid-fast filamentous bacilli with plenty of pus cells in the background were seen in pus aspirate only (not in punch biopsy specimens). No fungal elements were observed on the 20% KOH mount. Clinicians were notified immediately with the provisional report of possible Actinomycetoma due to Nocardia sp. Growth was observed within 9 days on SDA as well as LJ. It was a chalky white, dry colony to begin with that turned orangish-yellow in another week's time. Smear from the colony showed Gram-positive filamentous bacilli which on Modified ZN Smear were acid-fast filamentous beaded bacilli. The isolate was identified as Nocardia species. This was further confirmed as Nocardia brasiliensis by MALDI-TOF. On admission, the patient was initially started on Inj. Amikacin and then changed to Modified Raman regime of double dose Cotrimoxazole and Gentamicin. His lesions started showing improvement over 2 weeks of in-patient treatment. He was discharged on oral treatment thereafter. CONCLUSION: Abdominal wall clinical presentation of persistent progressive tumefaction with draining sinus with no granules caused by N. brasiliensis is a rare clinical entity as Mycetoma. The differential diagnosis would lead to either bacterial or fungal etiology or neoplasia. Delay in correct diagnosis led to the chronicity of the clinical presentation with inappropriate therapy. For a chronic destructive debilitating infective mycetoma presentation, appropriate microbiological diagnostics become essential to have early correct detection with proper sampling technique to guide the appropriate therapy as per the causative pathogen.