Cystic Squamous Cell Carcinomas of the Jaws: Twelve Cases Highlighting Histopathological Pitfalls.

Cystic squamous cell carcinomas (SCCs) of the jaws, including carcinoma cuniculatum, are rare, slow growing, and relentlessly invasive. The aim of this article is to present 12 cases, 4 of which were designated as carcinoma cuniculatum on the basis of deeply endophytic, anastomosing channels of cystic stratified squamous epithelium and keratin microabscesses. The other 8 were also cystic, but more heterogeneous morphologically and were diagnosed as well differentiated SCCs. Six patients were female, 6 were male (mean age = 74.0 years, range = 50-94 years). Six tumors affected the mandible, 6 the maxillary alveolus with or without extension into the hard palate. All patients underwent primary resection with neck dissection and were staged as T4a N0 M0. In 4 patients, diagnosis was delayed as a result of superficial biopsies and/or confusing histopathology. Cystic SCCs of the jaws can be difficult to diagnose and clinicoradiological correlation is essential. Long-term follow-up is mandatory.

A needle free system for cervical lymphatic mapping and sentinel node biopsy in oral squamous cell carcinoma.

The techniques of lymphatic mapping and sentinel node biopsy are finding increasing utility in the management of the loco-regional lymphatics in many areas of oncology. Our unit is currently investigating their feasibility in relation to the management of the clinically node negative neck in oral squamous cell carcinoma. In order to reduce patient discomfort, and to remove the possibility of sharps injury, particularly in the high-risk patient, we report the use of a needle free device for the intra-oral delivery of the radiopharmaceutical. We believe that this is the first report using such a device in the oral cavity for the purpose of lymphoscintigraphy, and that it has significant advantages over the conventional hypodermic needle in certain patient groups.

Metastasising clear cell odontogenic carcinoma: a case report and review of the literature.

Primary odontogenic carcinomas are rare and examples which have metastasised are even more uncommon. We describe the first reported case of a clear cell odontogenic carcinoma which metastasised to distant bones, namely the 5th lumbar vertebra and hip, 3 years after initial diagnosis. The initial incisional biopsy was thought to represent a calcifying epithelial odontogenic tumour, but in the subsequent resection the tumour showed a prominent clear cell component admixed with squamous cells showing peripheral palisading, widespread infiltration and necrosis indicating a malignant neoplasm. Radiologically guided biopsy revealed a metastatic lesion in L5 vertebrae and left hip, confirmed by immunohistochemistry. The metastatic lesion had similar appearances to the first biopsy, and diagnosis was confirmed by comparison of histological features, immunohistochemistry and exclusion of a second primary lesion by clinical examination and imaging. The diagnosis of clear cell odontogenic carcinoma is a difficult one to make. The behaviour of these tumours is unpredictable. This case confirms that clear cell odontogenic carcinomas have the potential for distant metastasis and require long-term follow up.

Does the method of resection affect the margins of tumours in the oral cavity? Prospective controlled study in pigs.

It is important to obtain tumour-free resection margins in patients with oral cancer. Pathological processing is known to cause tissue to shrink, which affects the reported margins, and it is postulated that the method of resection also has an effect. We marked standardised simulated lesions on the tongues of 15 live anaesthetised pigs and divided each lesion into four equal sections. They were resected each with a margin of 10mm using cutting diathermy, coagulative diathermy, Harmonic scalpel, and a conventional scalpel. After processing, the excision margins were measured. With cutting diathermy and coagulative diathermy, shrinkage of the soft tissues was minimal relative to the margin of the simulated lesion compared with the Harmonic scalpel (p=0.001) and conventional scalpel (p=0.001). Cutting diathermy and coagulative diathermy caused significant thermal damage (p=0.001). The method of resection affects the surgical margin. Diathermy resulted in thermal injury and denaturing of the underlying muscle, but there was less tissue contraction than when the Harmonic scalpel and conventional scalpel were used. The ethics committee approved the study, which was undertaken in a registered European Scientific Institute in Hamburg.