Paraganglioma. (section Endocrine Pathology)

Paraganglioma normally occurs in sites that parallel the\nsympathetic and parasympathetic chain ganglions. Common\nlocations of paraganglioma include tumours of paraganglionic\nsystem in head and neck region like carotid body paraganglioma\nand jugulotypmanic paraganglioma. There are also paragangliomas\nthat occur outside the usual distribution of sympathetic and\nparasympathetic paraganglia. Pathological diagnosis of paraganglioma\ndepends on the characteristic histological features and\nimmnohistochemical detection of neuroendocrine marker(s).\nComposite paragangliomas (paragangliomas with features of\nganglioneuroma or ganglioneuroblastoma) are sometimes\nnoted. The malignant potential of paraganglioma is difficult\nto be assessed. Assessment systems have been proposed\nin the pathology reporting of paraganglioma in order to predict\nthe malignant behaviour of the tumour. In this context, proliferative\nactivity obtained from Ki-67 immunohistochemical\nstaining should be provided in the reporting of paraganglioma.\nRecent developments in molecular genetics have expanded\nthe spectrum of disorders associated with paragangliomas.\nThe relevant clinical impact in pathology is the role of pathologist\nin the detection of SDHB by immunohistochemistry in\nparaganglioma as SDHB mutations are strongly correlated with\nhead and neck paraganglioma, presence of metastasis and poor\nprognosis. A high index of suspicion should be applied as\nparaganglioma occur in diverse sites. Also, awareness of the\nneed of updated pathological and immunological data are essential\nfor proper management of patients with paraganglioma.