Ramdas Das Sheima1, Chettithodi Sivasankaran Bindu2, Purushotham Rao Latha3
Oral cancer accounts for 30% of cancers in India.1 Of these, the tumours that abut on mandible show a greater local recurrence. This includes the tumours on mandibular alveolar ridge, lower buccal sulcus, sublingual sulcus and mandibular retromolar area.2,3 So, it is important to assess the histopathological features of these tumours to identify the factors related to prognosis and plan the surgical resection accordingly. The aims of the study1. Histopathological characterisation of oral squamous cell carcinoma of the mandibular region. 2. Evaluation of the underlying mandible for marrow invasion and perineural tumour invasion.
MATERIALS AND METHODS
50 resection specimens of squamous cell carcinoma of the mandibular region received in Department of Pathology, Medical College, Thiruvananthapuram, and sent from the Department of Surgical Oncology, Regional Cancer Centre, Thiruvananthapuram, from May 2000 to August 2001 were included. The clinical factors like site, size of tumour, proximity and fixity to the mandible, history of radiation and evidence of bone invasion were checked. Hemimandibulectomy specimens were cut buccolingually and representative bits were processed after decalcification.
72% of the tumours in the lower alveolus showed mandibular bone invasion while those in buccal mucosa and tongue did not. The infiltrative pattern was associated with deeper invasion of the bone. Perineural and intraneural infiltration of inferior alveolar nerve occurred in 16.7% and 5%. Marrow fibrosis was the commonest tissue response to tumour invasion.
Mandibular resection is essential for large tumours, which are located on the alveolar ridge with clinical fixity to the mandible. An infiltrative pattern of bone invasion and perineural involvement are seen in more aggressive tumours.