Cyst-like lesion in the coronoid process of the mandible is a challenging diagnosis to make, as it may present with a range of non-specific symptoms. A middle-aged woman reported a one-year history of non-bloody, pus discharge from the right angle of the mandible. There was a history of prior surgery comprising teeth removal two years ago for a painful swelling on the right side of her face, following which her symptoms regressed but in the due course, she developed a chronic sinus with draining abscess. Radiographic findings, in combination with clinical symptoms, are critical in the diagnosis and evaluation of cysts and cyst-like lesions of the jaws. The orthopantomograph (OPG) revealed a cyst-like lesion in the coronoid process of the mandible with an extra-oral sinus tract leading to the epicenter of the cyst-like radiolucency, and so this, in combination with the patient's atypical symptoms, presented a diagnostic challenge. This case report explores the events which led to the diagnosis of osteomyelitis and shows several unique learning points.

Nasal Chondromesenchymal Hamartoma (NCMH) is a rare, benign tumour of sinonasal tract usually seen in infants. Even though it is benign in origin, its aggressive clinical behaviour and florid radiological finding always mislead the initial diagnosis, mimicking a malignant sinonasal tumour. We report a case of NCMH in a 2-year-old boy who was referred by an ophthalmologist for progressive facial distortion, left eye proptosis, persistent left rhinorrhoea and epiphora. Biopsy obtained from the nasal cavity which appeared to be lobulated mass on endoscopic examination confirmed that it was Nasal Chondromesenchymal Hamartoma (NCMH). Surgical excision of the tumour was performed. The symptoms of NCMH depend on the tumour location, thus the clinical presentation can be varied. The only way to establish the diagnosis of NCMH is by histopathological and immunohistochemical examination of the tumour. Complete surgical treatment is advocated once the diagnosis is confirmed. This benign tumour has an established relation with the DICER1 mutations, hence other DICER1 tumours need to be ruled out at the time of diagnosis.