1/60. Thoracoscopic resection as the preferred approach to posterior mediastinal neurogenic tumors. Traditionally, resection of posterior mediastinal neurogenic tumors (PMNTs) has been through a posterolateral thoracotomy. Although thoracoscopic resection of these tumors has been advocated, treatment guidelines have not been reported previously. The authors report a thoracoscopic resection of a PMNT and conducted a retrospective review of similar cases in the literature. Successful thoracoscopic resection was compared with tumor size and type using a nonpaired t test (alpha: P < 0.05). A total of 29 patients (13 men, 16 women), aged 26 to 68 years, who underwent a thoracoscopic resection of a PMNT were identified. Preoperative imaging included chest radiography and computed tomography in all patients and magnetic resonance imaging in 15 of 29 patients (52%). All tumors were located in the posterior mediastinum without preoperative evidence of invasion or malignancy. Conversion to an open procedure was necessitated in 12 of 29 (41%) patients ("minithoracotomy" in 11, posterolateral thoracotomy in 1). Tumor size necessitating conversion to an open procedure (mean = 4.79 cm) and tumor size amenable to thoracoscopy alone (mean = 3.84 cm) were not significantly different (P < 0.09). pathology revealed 22 schwannomas (76%), 6 ganglioneuromas (21%), and 1 malignant schwannoma (3%) and was not associated with conversion to an open procedure (P < 0.99). Thoracoscopic resection of PMNTs can be performed successfully, regardless of tumor type or size; however, malignancy, local invasion, and tumors >5 cm may require an open procedure. Thoracoscopic resection can replace thoracotomy in the treatment of PMNTs. ( info) |
2/60. Atypical ganglion cell tumor of the sciatic nerve. CONTEXT: Although herniation of a lumbosacral intervertebral disk is a major cause of sciatic distribution pain, relentlessly progressive symptoms or signs should alert one to the possibility of a tumor involving the nerve. OBJECTIVE: To describe the clinical, neurophysiological, and histological features of a pathologically unique tumor involving the sciatic nerve. SETTING: Tertiary referral university hospital. PATIENT: A 36-year-old woman was seen with a 6-year history of increasingly severe symptoms in the distribution of the left sciatic nerve. RESULTS: electromyography indicated a sciatic nerve lesion in the region of the greater sciatic notch. magnetic resonance imaging demonstrated a tumor involving the left sciatic nerve in this area. light microscopy, electron microscopy, and immunohistochemistry results confirmed the presence of an atypical ganglion cell tumor of the sciatic nerve that exhibited prognostically conflicting clinical and histological features. CONCLUSIONS: To our knowledge, this is the first report of an atypical ganglion cell tumor affecting the sciatic nerve, and illustrates the value of detailed neurophysiological examination in localizing the site of peripheral nerve injury to facilitate focused neuroimaging when standard investigations are uninformative. Longer follow-up is required to determine the true biologic potential of this lesion. ( info) |
3/60. Intraoperative monitoring of an unusual brachial plexus tumor. This case illustrates the importance of intraoperative monitoring of neuronal function to help separate tumor tissue from neural tissue in a 54-year-old patient with left shoulder pain resulting from a desmoid tumor. Preoperative nerve conduction and electromyographic studies showed a lesion in the lateral cord of the brachial plexus, which was found to be intimately involved with the tumor mass and was splayed into a very thin effaced sheet of neural tissue. Stimulation of the tumor/nerve tissue mass proximal to the lesion was impossible due to the invasion of the brachial plexus by the tumor. The technique that was adapted for this unusual presentation was to stimulate the tumor/nerve tissue mass itself and record compound muscle action potentials distally. With the technique described, a subtotal resection of an aggressive fibromatosis enmeshed in the proximal brachial plexus was possible, and excellent relief of pain symptoms and retention of functional capabilities of the involved extremity were achieved. ( info) |
| The cytopathologic features of choroid plexus papilloma observed in the ventricular fluid of a 9-month-old boy are reported and compared with other pediatric central nervous system neoplasms. The cytologic features of choroid plexus papilloma are similar to those of normal choroid plexus and may be difficult to distinguish from those of a well-differentiated papillary ependymoma. However, the cell clusters are distinct from those associated with choroid plexus carcinoma and primitive neuroectodermal tumors. ( info) |
5/60. Gastrointestinal autonomic nerve tumours: a case report with ultrastructural and immunohistochemical studies. A case of gastrointestinal autonomic nerve tumour with light microscopic, immunohistochemical and ultrastructural examination is reported. The tumour was composed of spindle cells or large cells with clear cytoplasm and showed intense staining for vimentin and focal staining for neuron-specific enolase, chromogranin, synaptophysin, gastrin, P substance and S-100 protein. Ultrastructural examination showed long processes with dense core granules and the absence of features characteristic of other gastrointestinal stromal tumours. In addition we noted small traces of basal lamina and the absence of synaptic vesicles. It seems that the biological behaviour of gastrointestinal autonomic nerve tumours is aggressive but there are too few reports on which to conclude anything about their prognosis. Our findings suggest that tumour has a neuroectodermal differentiation. ( info) |
6/60. Fine needle aspiration cytology of primitive neuroectodermal tumors. A report of these cases. Primitive neuroectodermal tumor (PNET) is a small round cell malignancy arising in soft tissue and bone, predominantly in older children and adolescents. We report the cytomorphologic features and findings of ancillary studies of eight fine needle aspiration (FNA) biopsies from three patients (7-year-old male, 12-year-old female, 9-year-old female). Two of the biopsies suggested the initial diagnosis of PNET of the chest wall, while the remaining six documented recurrent or metastatic disease. In one of these cases the primary diagnosis made by FNA biopsy enabled the pediatric oncologists to give specific therapy for the unresectable tumor and achieve remission. Local recurrences included the chest wall (two cases), pleura (one case) and pericardium (one case), while metastatic disease involved the supraclavicular lymph node and breast. All the cases consisted of small malignant cells with a high nuclear/cytoplasmic ratio and hyperchromatic nuclei without prominent nucleoli. Homer Wright rosettes were seen in only two of the aspirates, and neuropil and ganglion cells were not present. Ancillary studies, including electron microscopy (two cases), immunocytochemistry (four aspirates from two cases) and cytogenetics (11/22 translocation, one case) performed on the aspirated material were aids in making a specific diagnosis and excluded other small round cell tumors of childhood, such as malignant lymphoma, rhabdomyosarcoma and Ewing's sarcoma. The differential diagnosis between PNET and neuroblastoma can be difficult on the basis of an FNA biopsy alone, although light microscopic morphologic differences exist. Clinical features (e.g., age, primary site, metastatic patterns), catecholamine levels, electron microscopy and cytogenetics are necessary in establishing the correct diagnosis. ( info) |
7/60. Primitive neuroectodermal tumor: CT, MRI, and angiographic findings. Primitive neuroectodermal tumors (PNETs) are uncommon CNS neoplasms found usually in the first decade of life. This article presents a proven case of this lesion in a 14-month-old boy located deep in the left frontal lobe. This lesion was studied by CT, MRI, and cerebral angiography. The radiologic findings of this tumor were assessed and compared with those cases reported in the medical literature. ( info) |
| Four cases of primitive neuroectodermal tumor (PNET) of the uterine corpus are reported, bringing the total number of reported PNETs in this site to seven. The four women were in their seventh decade of life and presented with abnormal vaginal bleeding and, in two cases, an enlarged uterus. The patients underwent total or subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy and, in one patient, pelvic lymphadenectomy. Three patients received postoperative radiation therapy, chemotherapy, or both. Gross examination revealed fleshy polypoid masses filling the endometrial cavity and, in two cases, deeply invading the myometrium. Histologic, immunohistochemical, and, in two cases, ultrastructural examination revealed typical PNETs that exhibited variable degrees of neural, glial, ependymal, and medulloepithelial differentiation. Two PNETs were admixed with other neoplasms: in one case a grade I endometrial adenocarcinoma and in the other a low-grade endometrial stromal sarcoma. The prognosis of the tumors was related to their stage: two patients with stage I tumor were alive with no evidence of disease at 5 and 6 years, whereas two patients with stage III or IV tumor died of tumor at 6 and 12 months. Although it has been suggested that uterine PNETs may be derived from displaced germ cells or implanted fetal tissues, evidence provided by this study, including the advanced ages of the patients and an admixture with neoplasms of unquestioned mullerian origin, suggests a mullerian origin for these tumors in at least some cases. ( info) |
9/60. The origin of extragonadal teratoma: case report of an immature teratoma occurring in a prenatal brain. We describe a massive congenital intracranial teratoma (MCIT), which had a normal chromosome banding pattern 46,XY karyotype and a normal diploid dna histogram, and which produced a variety of carcinoembryonic antigens. The volume density of primitive neural components (primitive neural tubes, small undifferentiated neuroepithelial cells, immature glial fibers and pigment cell components without neurofibrillar differentiation) was estimated to be 45%. We discuss the histogenesis, pathobiology and cell cycle kinetics. ( info) |
10/60. An unusual benign neural tumour with stellate-cell morphology. We report a stellate-cell dermal tumour which was studied by immunohistochemistry and electron microscopy. The stellate morphology of the tumour cells appeared to be due to retraction of their cytoplasm resulting in the emergence of intercellular spaces. Results of the immunohistochemical investigations were consistent with a neural tumour, but we could not assign it to any particular category of the known neural tumours. Therefore we have designated this tumour as an unusual, benign, neural-tumour with stellate-cell morphology. ( info) |