Subcutaneous entomophthoromycosis in an immunocompetent individual: a localised forearm swelling

A man in his 80s with no known comorbidities presented with diffuse swelling on the dorsal aspect of his right forearm for 3 months. Clinical features were suggestive of soft tissue sarcoma of the right forearm. A high resolution CT scan of the thorax showed allergic bronchopulmonary aspergillosis associated with mild mediastinal lymphadenopathy. MRI of the right upper limb showed a suspicious neoplastic/infective aetiology. A core biopsy of the right arm swelling found a granuloma with no malignancy features so an incisional biopsy of the lesion was carried out. This indicated granulomatous inflammation with excessive giant cell reaction and focal panniculitis with the possibility of a mycotic lesion. Bronchoalveolar lavage was negative for tuberculosis and fungal infection. After a multidisciplinary team discussion, the patient was started on antifungal medication. There was a marked reduction in both the size and consistency of the swelling after several weeks of oral itraconazole and potassium iodide solution. The purpose of this report is to increase the awareness of this uncommon treatable condition which, if misdiagnosed, could result in an inappropriate intervention.