Vikram Sanghvi

Detection of HPV-16 genome in human oral cancers and potentially malignant lesions from India.

The presence of high risk human papilloma virus (HPV) 16 and 18 was examined in 100 oral cancer patients of Indian descent, 80 patients with potentially malignant oral lesions and corresponding clinically normal mucosa from 48 of these patients. Additionally, presence of HPV-33, -6 and -11 was also studied in 86 oral cancers, 50 potentially malignant oral lesions and 30 corresponding normal oral mucosa. All the patients with oral cancer and oral lesions, were long term tobacco-chewers, and a majority of the patients were in Advanced Stages III and IV. The DNA samples were amplified by polymerase chain reaction (PCR) using HPV L1 consensus primers. Typing of HPV was performed by Southern hybridization analysis of the PCR products using HPV-16, -18, -33, -6 and -11 type specific oligonucleotide probes. HPV-16 was detected in 15 out of 100 (15%) oral tumours, 27 out of 80 (34%) potentially malignant lesions and 15 out of 48 (31%) of the corresponding normal mucosa in the patients with oral lesions. HPV-18 was not detected in any of the oral cancers, oral lesions and normal mucosa. HPV-33 and the low-risk HPV-6 and -11 were also not detected in the oral cancers, oral lesions and corresponding normal mucosa. A significantly higher prevalence of HPV-16 was observed in oral lesions (27 out of 80, 34%) as compared to oral cancers (15 out of 100, 15%). The observed difference of 19% (95% confidence interval [CI]: 6%, 31%), between these two proportions was statistically significant at the 5% level of significance. Our data indicates that HPV-16 may play a direct role in a certain proportion of oral cancers; whereas in a subpopulation of oral cancers HPV-16 infection may be vital in the early events associated with development of potentially malignant oral lesions, and the presence of the virus not essential in the progression of the oral lesion to frank malignancy.

Expression of bcl-2 and bax in chewing tobacco-induced oral cancers and oral lesions from India.

Deregulation of oncogenes and tumor suppressor genes involved in apoptosis has been associated with tumor development and progression. To investigate the involvement of apoptosis regulating proteins in oral cancer in Indian patients, primarily associated with chewing tobacco habits, immunohistochemical expression of bcl-2 and bax was examined in 63 oral squamous cell carcinomas, and 31 putative premalignant lesions. Our studies revealed overexpression of tumor specific cytoplasmic bcl-2 in 56% and bax in 43% oral cancers. The oral cancers in the Indian patients are preceded by premalignant oral lesions; hence oral lesions were examined for bcl-2 and bax expression. We observed aberrant expression of bcl-2 in 16% oral lesions comprising leukoplakias and SMF and bax in 55% oral lesions. We have already reported, p53 expression in these oral cancers and lesions. It was noteworthy that 30% oral cancers demonstrated a p53+bcl2+ pattern, and 14% samples exhibited p53+bcl2+bax+ pattern. However, none of the oral lesions showed concurrent deregulation of p53 and bcl-2 or all the three genes. Interestingly 45% oral lesions were p53-bax+ as compared to 18% oral cancers; while 39% oral lesions were bcl2-bax+ as compared to 14% oral cancers, indicating overexpression of bax in oral lesions, in the absence of p53 and bcl-2 proteins. Significant correlation was observed between positive nodal status and bcl2+ (p=0.047) and p53+bcl-2+ (p=0.01) in oral cancers. Kaplan Meier survival analysis showed significantly (p=0.059) higher survival in patients with p53-oral tumors than with p53+ tumors. Our studies thus indicate frequent overexpression of apoptosis regulators bcl-2, bax and p53 proteins in oral cancers, and a subset of oral lesions, representing early events in oral carcinogenesis. The aberrant bcl-2 expression and loss of p53 function observed, may play an important role in the tumorigenesis of oral cancers by allowing escape from apoptosis and enabling additional genetic alterations to accrue.

Lateral thyrotomy for neurilemmoma of the larynx

We present a rare case of neurilemmoma of the larynx, which was excised through a lateral thyrotomy approach with resulting restoration of laryngeal function. The advantage of the lateral thyrotomy approach for submucous tumours of the larynx is discussed.

Transventricular paraganglioma of the larynx.

Laryngeal paragangliomas are rare neuroendocrine tumours. Most laryngeal paragangliomas are supraglottic in location, with only 3% reported to be glottic in location. We present a rare case of transventricular paraganglioma with fixation of the hemilarynx that presented a diagnostic and therapeutic challenge.

The new combined surgical approach for cancer involving the base of tongue-supraglottic complex

The base of the tongue, valleculae, preepiglottic space, and supraglottic area of the larynx develop from an unpaired central area, i.e., “hypobranchial eminence,” unlike oral tongue and vocal cords, which are independently unilateral and paired in character. These areas should be known as “base of tongue‐supraglottic complex.” Lymphatic criss‐cross is common in this area

Epidermotropic cutaneous metastases from hypopharyngeal carcinoma.

Cutaneous metastases from laryngeal and hypopharyngeal squamous carcinomas are extremely rare. A high index of clinical suspicion, supplemented with histopathologic evidence, aids in the diagnosis. The prognosis is extremely poor, and treatment is aimed only at palliation of symptoms and improving quality of life.

Differentiated thyroid cancer invading the hypopharynx: A case report.

Most thyroid cancers (90–95%) are well differentiated. Well differentiated cancers of the thyroid are usually confined to the thyroid capsule, making them amenable to isolated thyroid resection. Invasion of the upper aerodigestive tract by these cancers is infrequent and hypopharyngeal invasion is still rare. We report a 51 year old man with thyroid cancer invading the hypopharynx, who was successfully managed with complete resection along with a partial pharyngectomy. He is asymptomatic and disease free eighteen months after surgery. We advocate aggressive surgical extirpation of thyroid carcinoma invading the upper aerodigestive tract.