Absence of BRAFV600E immunohistochemical expression in sporadic odontogenic keratocyst, syndromic odontogenic keratocyst and orthokeratinized odontogenic cyst.

BACKGROUND: Odontogenic keratocyst (OKC) is a unique developmental odontogenic cyst that has the potential to behave aggressively and is associated with the nevoid basal cell carcinoma syndrome. Orthokeratinized odontogenic cyst (OOC) is a distinct, uncommon odontogenic cyst. It significantly differs from OKC not only in its epithelial lining but also in proliferating kinetics, clinical, immunohistochemical and biological behaviour. BRAF gene located on chromosome 7q34 encodes a cytoplasmic serine-threonine kinase. Various immunohistochemical studies have been conducted to express the BRAFV600E gene mutation in various odontogenic cyst and tumours with varying results. The present study was conducted to evaluate the possible role of BRAFV600E in the pathogenesis of sporadic OKC, syndromic OKC and OOC by immunohistochemistry. METHODS: Formalin-fixed paraffin-embedded (FFPE) tissue blocks of 15 diagnosed cases each of sporadic OKC, syndromic OKC and OOC were retrieved from the archives of Department of Oral Pathology and subjected to immunohistochemical staining for the detection of BRAFV600E mutation using a novel rabbit monoclonal antibody clone RM8. RESULTS: Immunohistochemical analysis showed complete absence of BRAFV600E mutation in all cases of sporadic OKC, syndromic OKC and OOC. CONCLUSION: The negative immunohistochemical expression of BRAFV600E in sporadic OKC, syndromic OKC and OOC suggests that BRAFV600E plays no role in the pathogenesis of sporadic OKC, syndromic OKC and OOC.

Giant Multilobular Lipoma of Neck - A Case Report.

RATIONALE: Presenting a rare case report of a giant multilobular lipoma in submandibular and submental spaces of anterior and lateral aspect of neck. PATIENT'S CONCERNS: The patient's main concern was persistent diffuse swelling in right lower face and neck region for 5-6 years. DIAGNOSIS: The lesion was diagnosed as multiple septate lipoma measuring 11.5 cm × 10.5 cm × 6.5 cm involving submandibular region and anterior triangle of the right neck following fine-needle aspiration cytology and radiological imaging. TREATMENT: Extraorally complete surgical excision was carried out through submandibular approach under general anesthesia. OUTCOMES: The patient's postoperative recovery was uneventful. The patient was followed up on a monthly basis for 6 months. No recurrence was observed. The patient was satisfied with the treatment. LESSONS: Lipomas should be considered as a rare differential diagnosis for anterior neck swelling. Biopsy is not necessary to confirm the diagnosis. Surgical excision remains the mainstay of treatment following final diagnosis through imaging modalities.

The Role of Increased Connective Tissue Growth Factor in the Pathogenesis of Oral Submucous Fibrosis and its Malignant Transformation-An Immunohistochemical Study.

Connective tissue growth factor (CTGF), a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins, is highly expressed in various organ fibrosis and several malignant tumors. Although a few studies have been conducted using CTGF in oral submucous fibrosis (OSF) and oral squamous cell carcinoma, no study has demonstrated its relation with various stages of OSF and its malignant transformation. The present study investigated the possible role of CTGF in the pathogenesis of OSF and its malignant transformation by using immunohistochemistry. Ten formalin-fixed paraffin-embedded tissue blocks, each of Stage 1 OSF, Stage 2 OSF, Stage 3 OSF, Stage 4 OSF, well- differentiated squamous cell carcinoma (WDSCC) with OSF and WDSCC without OSF were stained for CTGF by immunohistochemistry. Ten cases of healthy buccal mucosa (NOM) were included as controls. The present study demonstrated a statistically significant expression of CTGF in the epithelium and connective tissue of OSF and WDSCC with and without OSF cases against its complete absence in NOM. We observed an upregulation of CTGF expression from NOM to various stages of OSF to WDSCC with or without OSF. A gradual upregulation of the CTGF expression in various stages of OSF to WDSCC (with and without OSF) against its complete absence in NOM suggests that CTGF plays an important role in the pathogenesis of OSF and its malignant transformation.