To review the aetiopathogenesis, clinical characteristics, immunohistochemical profile, prognosis and treatment options for primary thyroid squamous cell carcinoma, and to compare it with squamous cell carcinoma metastatic to the thyroid, thus providing the reader with a framework for differentiating primary and secondary disease.

Review of English language literature from the past 25 years.

A search of the Medline, Embase and Cochrane databases (April 1984 to April 2009) was undertaken to enable a comprehensive review.

After applying strict criteria for the diagnosis of primary thyroid squamous cell carcinoma, 28 articles were identified reporting 84 cases. When reviewing secondary thyroid squamous cell carcinoma, we only analysed cases of squamous cell carcinoma metastatic to the thyroid gland, and found 28 articles reporting 78 cases.

It is possible to differentiate between primary and secondary thyroid squamous cell carcinoma, on the basis of combined evidence from clinical examination and endoscopic, pathological and radiological evaluation. Such differentiation is important, as the prognosis for primary squamous cell carcinoma is uniformly poor irrespective of treatment, and the most suitable option may be supportive therapy. Treatment for secondary squamous cell carcinoma of the thyroid varies with the site and extent of spread of the primary tumour.

Telomere length must be maintained throughout cancer cell progression and proliferation. In most tumours, telomerase activity maintains telomere length. Therefore, telomerase is a target for cancer treatments. However, some cancer cells maintain telomere length through an alternative mechanism termed ‘alternative lengthening of telomeres’. To determine how telomerase inhibition relates to the initiation of the alternative lengthening of telomeres pathway, we investigated telomerase activity and telomere maintenance in Hep-2 cells with and without reduced telomerase activity.

We investigated telomerase activity levels in a normal Hep-2 cell line and in residual cells following telomerase inhibition treatment. Additionally, we looked for expression of a marker protein for the alternative lengthening of telomeres mechanism.

In the residual cells, telomerase activity was eliminated. However, these cells had higher levels of the alternative lengthening of telomeres biomarker, suggesting an alternative mechanism for telomere maintenance following telomerase inhibition. These results could have a major impact on the design of new cancer treatments.

Management of patients with head and neck squamous cell carcinoma is often based on clinical parameters, with little appreciation of the underlying tumour biology. Single biological marker studies fail to acknowledge the complexity of these tumours. Our aim was to define a profile of biological markers associated with outcome.

This retrospective study involved consecutive patients with oropharyngeal squamous cell carcinoma treated with primary radiotherapy between 1996 and 2001. Pre-treatment biopsies were used to study the immunohistochemical expression of nine biological markers. Markers were chosen to reflect biologically relevant pathways.

Following analysis of nine markers, a profile of two markers was derived (carbonic anhydrase 9 and major vault protein), the co-expression of which conferred a significantly poor probability of locoregional control. The prognostic effect of these biomarkers in combination was greater than their effect individually.

Biomarker profiles can be established which highlight large differences in locoregional control. Identifying tumours that express both carbonic anhydrase 9 and major vault protein may facilitate patient selection for more aggressive treatment.

The presence of distant metastases affects the therapeutic regime in patients with head and neck squamous cell carcinoma. This study evaluated the necessity to undertake bone scanning, chest computed tomography and abdominal ultrasonography in patients presenting with primary advanced head and neck squamous cell carcinoma.

Retrospective analysis, university setting.

One hundred and sixty-three patients with head and neck squamous cell carcinoma who were scheduled for major surgery underwent screening for distant metastases. Chest, head and neck computed tomography, abdominal ultrasonography and bone scanning were performed in all patients.

Distant metastases were detected in 5.52 per cent of the 163 patients. All of these patients had locoregional advanced (stage IV) tumours. Computed tomography scanning of the lungs revealed metastases in six patients. Bone metastases were found in three patients. Only one patient with primary liver metastases was detected by abdominal ultrasonography; this patient also had pulmonary metastases.

Computed tomography of the thorax is the most important technique for screening patients with head and neck squamous cell carcinoma.

To review our experience of the treatment of primary tracheal tumours.

All medical notes of patients with primary tracheal tumours diagnosed between 1981 and 2002 were retrospectively analysed.

In this period, 80 patients were diagnosed with primary tracheal malignancy, 48 males and 32 females. The median age was 48 years. Sixty-nine patients had malignant tumours, most commonly adenoid cystic carcinoma (50.7 per cent) or squamous cell carcinoma (30.4 per cent). Fifty-five patients underwent surgery, 30 of whom also received radiotherapy. Twenty-five patients received only radiotherapy. The five-year survival rate for all malignant tumours was 30.5 per cent. The five-year survival rates for adenoid cystic carcinoma and squamous cell carcinoma were 40.2 and 24.6 per cent, respectively. Local recurrence and distant metastases developed in 21 patients (30.4 per cent).

Primary tracheal tumours are rare and mainly malignant. Surgery is the most effective treatment method. Technical advances allow for safe resection of the tumour with a safe, tension-free anastomosis.

We report a unique case of a squamous cell carcinoma of the larynx presenting as a large pseudolaryngocoele, arising through a thyroid cartilage defect.

Case report and review of the literature.

A 47-year-old man presented with a two-month history of hoarseness and a large, midline neck swelling. Endoscopic examination revealed a transglottic carcinoma involving the anterior commissure. Fine needle aspiration of the neck mass showed it to be an air-filled structure which transiently collapsed but refilled within minutes. Subsequent computed tomography scanning and histopathological examination revealed that the air-filled mass was created by a defect in the thyroid cartilage, with formation of a pseudolaryngocoele.

The anatomy of the anterior commissure region and its effect on the spread of laryngeal carcinoma is reviewed in order to explain the pathophysiology of this unusual presentation. We highlight the need for a high index of suspicion of malignancy if a laryngocoele or pseudolaryngocoele is detected clinically.