The Management of Locally Invasive Primary Thyroid Paraganglioma: A Case Report and Review of the Literature.

Paragangliomas (PG) are very rare neuroendocrine tumours, arising from neural crest derived paraganglia of the autonomic nervous system. Primary thyroid paraganglioma (PTPG) is a rare site of PG and only 45 cases have been previously reported. The preoperative diagnosis of PTPGs presents a challenge as the clinical, cytological and histological features overlap with more common primary thyroid cancers. A 55 year old male was found to have significant enlargement of the left lobe of his thyroid. Following lobectomy, the thyroid lobe showed unencapsulated tumour which was positive for synaptophysin, CD56 and S100 (sustentacular cells). Post-operative imaging demonstrated incomplete resection. There was no post-operative radiotherapy and monitoring was by 6-12 monthly MRI. 48 months after his surgery he is alive and well with no evidence of disease progression. The diagnosis of PTPG was only made postoperatively, and although rare should be considered in the differential diagnosis of a hypervascular thyroid nodule.

Primary gynaecological tumours mistaken for metastases: report of two cases with review of literature.

We describe two neoplasms of rare occurrence, one of ovarian and the other of uterine origin that were sent for consultation. Both lesions were diagnosed as metastatic carcinomas by pathologists with special interest in gynaecological pathology. The cases were referred for a second opinion because of subsequent failure to identify the primary source. We discuss the differential diagnoses, the need for generous sampling particularly in ovarian mucinous neoplasms and the value of including particular antibodies in the panel to aid the diagnostic process. Metastatic tumours mimicking primary tumours are always challenging. These two cases illustrate the need to be vigilant against the reverse scenario as well.

Pheochromocytomas, PASS, and immunohistochemistry.

Differentiation between malignant and benign pheochromocytomas of the adrenal gland traditionally relies on the presence of clinically detectable metastases. The PASS system for differentiating between benign and malignant pheochromocytomas is based on defined morphological criteria, of which some are related to tumour cell proliferation and survival. Immunohistochemical markers for important events in the cell cycle were explored in order to characterise differences in apoptosis, G1 checkpoints, and S phase in more detail. A panel consisting of p53, tenascin, bcl-2, pRb, cyclin D1, mcm2, and p27 was employed. Only for pRb a statistically significant difference between PASS 3 and less and PASS 4+ tumours was detected, indicating qualitative differences in the mitotic cycle, probably immediately before early S phase. These results are discussed in relation to similar studies in recent literature.