GD11: An unusual lip ulcer

Siwaporn Hiranput,¹ Paul Devakar Yesudian,¹ Krishnakumar Subramanian² and Frederick Manuel³

¹Wrexham Maelor Hospital, Wrexham, UK; ²L&T Ophthalmic Pathology Department, Vision Research Foundation, Chennai, India; and ³Global Skin Centre, Chennai, India

A 14-year-old schoolboy from rural South India presented with a lower-lip lesion, which started as a red spot and increased in extent over a year. It was asymptomatic and the patient remained systemically well. There was no relevant past medical history. Examination revealed a soft, friable, nontender hypertrophic plaque on the right side of the lower lip extending to the buccal mucosa beyond the inferior labial frenulum. There was no palpable lymphadenopathy. Venereal disease research laboratory and HIV tests were negative. An incisional biopsy showed foreign body giant cell granulomas containing sclerotic cells, which were characteristic of chromoblastomycosis. Further staining with Grocott-Gomori’s Methenamine Silver (GMS) confirmed clusters of fungal organisms. Chromoblastomycosis is caused by dematiaceous fungi, including Fonsecaea pedrosoi and Phialophora verrucosa. They have typical brown pigmentation in the cell walls due to the presence of melanin and it is prevalent in humid tropical and subtropical climates. They thrive in wood, soil and organic matter; hence, the disease is often reported in agricultural workers, particularly those who walk barefoot. The fungus enters the body following skin trauma; exposed sites such as the lower limbs are often affected. The common presentation is a painless, slow-growing verrucous plaque, which is thought to develop as a result of dysregulation in the T helper (Th)1/Th2 response where the Th2 immune response predominates, resulting in a reduced inflammatory response against the fungus. Koebnerization has been reported, giving rise to satellite lesions. There may be lymphatic spread that results in a sporotrichoid pattern. The fungi produce thick-walled, single or multicellular clusters called sclerotic or muriform bodies, respectively. These can be detected on histology and are pathognomonic for chromoblastomycosis. Black dots (sclerotic bodies) may be visible on the surface of the plaque. Scraping from the surface of the lesion for mycology could be considered. Secondary bacterial infection, ulceration and squamous cell carcinoma may develop as complications. Treatment with prolonged courses of oral antifungals like itraconazole and terbinafine results in a good clinical response. For large plaques, a combination of systemic antifungals and surgery to excise the lesion may be considered. The disease runs a chronic course but is not fatal. The prognosis is excellent if the condition is diagnosed and treated early. This is the first reported case of primary chromoblastomycosis of the oral mucosa in an immunocompetent child. Deep fungal infections such as chromoblastomycosis could be considered as a differential diagnosis for oral lesions, especially in patients with relevant risk factors.