Malignant chemodectoma of posterior mediastinum

[Neurogenic tumors of the mediastinum in adults]

In adults, mediastinal neurogenic tumours constitute the third group of mediastinal tumours, after thymomas and lymphomas. If the group of neurogenic tumour is frequent, each type of tumour is relatively unusual in everyday's clinic. Among them, nerve sheath tumours are the more frequent, followed by tumour of the autonomic system. Askin tumour remains uncommon. Treatment of this tumour requires complete preoperative work-up, including standard radiography, CT-scan, MRI, and sometimes nuclear imaging. In most cases, the treatment is based on surgical resection, and may be associated with radiotherapy or chemotherapy in case of malignant tumour or incomplete resection. Better understanding of these tumours, including their molecular abnormalities, may lead to new changes in their classifications, and to their management.

Primary care patients in the emergency department: who are they? A review of the definition of the 'primary care patient' in the emergency department

OBJECTIVE

To review the definition of 'primary care' and 'inappropriate' patients in ED and develop a generally acceptable working definition of a 'primary care' presentation in ED.

METHOD

A Medline review of articles on primary care in ED and the definitions used.

RESULTS

A total of 34 reviewed papers contained a proposed definition or comment on the definition for potential 'primary care', 'general practice', or 'inappropriate' patients in ED. A representative definition was developed premised on the common factors in these papers: low urgency/acuity--triage categories four or five in the Australasian Triage Scale, self-referred--by definition, patients referred by general practitioner/community primary medical services are not primary care cases because a primary care service has referred them on, presenting for a new episode of care (i.e. not a planned return because planned returns are not self-referred), unlikely to be admitted (in the opinion of Emergency Nurse interviewers) or ultimately not admitted.

DISCUSSION

This definition can be applied either prospectively or retrospectively, depending on the purpose. Appropriateness must be considered in light of a legitimate role for ED in primary care and the balance of resources between primary care and emergency medicine in local settings.

Primary ependymoma of the mediastinum: a clinicopathologic study of three cases

Primary mediastinal ependymomas are unusual tumors, with only two case reports previously reported in the literature. In this study, we review our experience with three cases of primary mediastinal ependymomas, including the clinical, histopathologic, immunohistochemical, and ultrastructural features. The three patients in this study were white women with a mean age of 50 years (age range, 36 to 71 years). Presenting symptoms were nonspecific; radiographically, all lesions were circumscribed posterior mediastinal masses without evidence of bone involvement. There was no evidence of central nervous system, sacral, or pelvic ependymoma. All tumors were completely resected, ranged in size from 5 to 7 cm (mean, 6 cm), and exhibited glistening pseudocapsules. Two tumors had a solid, tan-gray cut surface and one lesion was cystic with a mural tumor nodule. All neoplasms showed histologic features of conventional cellular ependymomas with perivascular pseudorosettes and occasional true ependymal rosettes. Germ cell components were not present in any case and immunohistochemical analysis showed glial fibrillary acidic protein, S-100, and patchy cytokeratin immunoreactivity in all three cases as well as absence of reactivity for HMB 45, chromogranin, and synaptophysin. Ultrastructural features included multipart "zipper-like" junctions, intracytoplasmic lumina containing microvilli, occasional cytoplasmic basal bodies, and apical cilia. A microscopic metastasis was present in a regional lymph node in one case at the time of resection; however, there is no evidence of recurrence or distant metastasis in any of the cases during the postoperative period (mean length of follow-up, 64 months). Ependymomas rarely occur in the mediastinum and have a predilection for the posterior mediastinum. The paravertebral location, microscopic identification of adjacent sympathetic ganglia, and lack of teratomatous or other germ cell components suggest that mediastinal ependymomas are likely derived from paravertebral ependymal rests. Primary mediastinal ependymomas are characterized by a prolonged and indolent clinical course. Metastasis to regional lymph nodes may occur, but distant metastases are unusual in our experience. Complete surgical excision seems to offer the best chance for long-term survival.

Nonfunctioning malignant paraganglioma of the posterior mediastinum with spinal cord compression. A case report

STUDY DESIGN

Case report and review of the literature.

OBJECTIVE

To present a case with an uncommon nonfunctioning malignant paraganglioma of the posterior mediastinum with compression of the spinal cord. An update survey is given with respect to diagnostic, histopathologic, and therapeutic aspects of paragangliomas.

SUMMARY OF BACKGROUND DATA

Paragangliomas in the posterior mediastinum are uncommon and rarely may produce spinal cord compression. To illustrate the low incidence, only two cases of paraganglioma of the posterior mediastinum were reported by the Mayo Clinic, Rochester, Minnesota, during a 40-year period.

METHOD

Case report and review of the literature.

RESULT

The diagnosis was made by modern imaging techniques (computed tomography, magnetic resonance imaging, and metaiodobenzylguanidine scan) and verified by computed tomography guided per thoracic puncture. A wide local resection was performed; the patient is disease-free 1 year after surgery.

CONCLUSION

The uncertainty of prognosis and possibility of local recurrence of paragangliomas even after a long period emphasizes the importance of wide local surgical resection with or without adjuvant therapy and makes long-term follow-up and continued surveillance of the patient mandatory.

Malignant paraganglioma of the posterior mediastinum. A case report and review of the literature

A case of malignant paraganglioma arising from the posterior mediastinum and presenting with a chest wall metastasis is reported with immunocytochemical and ultrastructural documentation. The pathobiologic features of this rare disease are reassessed with a review of the literature. Cytoarchitectural features do not provide reliable information regarding malignant potential. However, evidence of local invasiveness at surgical exploration and/or lack of initial surgical control are likely to be associated with synchronous or metachronous metastatic disease. Although there are clinicopathologic differences warranting distinction between benign paragangliomas arising in the anterior and posterior mediastinal compartments, there is no apparent pathobiologic difference with regard to the malignant group.