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A V Vallat-Decouvelaere

Publications and source records attributed to A V Vallat-Decouvelaere.

5 recordsLinked to original sources
PubMed2000

[Histology and elementary pathology of the peripheral nerve].

The lesions which give rise to peripheral neuropathy are induced by a variety of mechanisms. Their etiology can often be established from the results of electrophysiological examination and (or) study of nerve biopsy; knowledge of the etiology will guide the treatment strategy. In this chapter, we discuss typical lesional mechanisms including: axonal involvement (Wallerian degeneration, axonopathies) and demyelinating lesions (whether segmental, indicative of an acquired inflammatory process, or of a more extensive nature, indicative of a genetic origin). The indication for nerve biopsy, which enables identification of the lesions, should be considered on a case by case basis.

Axons↗
PubMed2000

So-called malignant and extra-ventricular neurocytomas: reality or wrong diagnosis? A critical review about two overdiagnosed cases.

Central neurocytoma (CN) is described as a rare intra-ventricular benign neuronal tumor of the brain. Two primary tumors first diagnosed as malignant and extra-ventricular neurocytomas are reported here. Histologically, the tumor of the first patient, a forty-one-year-old man, consisted of monotonous cells with round nuclei, but no fibrillar background. The second tumor, in a nineteen-year-old girl, showed areas of moderately pleomorphic round cells, with numerous rosettes and ganglion cell differentiation, in an abundant fibrillary network. Both presented calcifications. Mitoses were more frequent in recurrences and spinal locations than in the primaries. All tumors stained strongly for synaptophysin, and GFAP was partly positive in the first case only. Patients received post-surgical radiotherapy and were still alive eight and six years, respectively, after initial surgery. The interpretation of atypical cases, such as ours is not easy: the diagnoses finally retained were oligodendroglioma in the first case and ganglioneuroblastoma in the second case. Furthermore, neurocytomas atypical either by their unusual topographical or histological presentation or by their poor prognosis, have been frequently entitled in this way on synaptophysin positivity. So, we were prompted to reassess the entity of CN, seventeen years after the first description, to re-appreciate the reality of anatomo-clinical variants and to discuss the value of synaptophysin positivity in these tumors. In conclusion, it seems preferable to individualize true classical CN, which has a favorable outcome, from so-called extra-ventricular, atypical and anaplastic, clinically malignant neurocytomas for which complementary treatment is required.

Adolescent↗
PubMed1999

Spinal melanotic schwannoma: a tumour with poor prognosis.

AIM: To clarify the prognosis of melanotic schwannoma. This is a rare tumour which is generally considered as a benign lesion, reported in many cases with a short follow-up only. METHODS AND RESULTS: Five cases of spinal melanotic schwannoma were retrospectively studied. The tumours were examined using standard histological, immunohistochemical and ultrastructural methods. No features of malignancy (high mitotic count, atypia or necrosis) were found in the primary tumours. The follow-up period ranged from 3 to 7 years. Malignant clinical behaviour was clear-cut in four cases: three patients died from metastases to various sites and one presented several discrete spinal tumours of the same type seven years after the first operation. Only one patient presented no recurrence and was free of disease 6 years after initial diagnosis. The review of 57 cases of the literature (including our cases), showed that 15% of the cases had recurrences and 26.3% were complicated by metastasis. Only 53% of the cases followed for more than 5 years, were free of disease vs. 67.5% of the cases with shorter follow-up. Twenty additional cases had no follow-up. CONCLUSION: Appropriate long-term follow-up is required for all melanotic schwannomas, as it may recur or metastasize after more than 5 years, even in the absence of overt malignant histological features.

Adult↗
PubMed1998

Atypical and malignant solitary fibrous tumors in extrathoracic locations: evidence of their comparability to intra-thoracic tumors.

Solitary fibrous tumor (SFT), first described as a pleural lesion, has been reported at numerous extrathoracic sites over the past 10 years. About 10% to 15% of intrathoracic SFTs are histologically or clinically malignant, but such cases have very rarely been described at other locations. Among 92 cases of extrathoracic SFT in our files, we identified 10 that either had recurred (2 cases) or had a least one atypical histologic feature (8 cases). The ten tumors occurred in five men and five women, 32 to 81 years old (median 56), measured 1.9 cm to 20 cm (median 11.5 cm), and were located in the abdomen/pelvis (4 cases), retroperitoneum (3 cases), groin, trunk, and upper arm. Nuclear atypia (8 cases), markedly increased cellularity (6 cases), areas of necrosis (4 cases), and greater than 4 mitoses/10 HPFs (3 cases) were seen in addition to the typical histologic features of SFT. Six tumors had at least two of these atypical histologic features. Nine cases were positive for CD34, six were positive for O-13, and one was focally positive for smooth muscle actin. Eight were excised completely. Subsequent follow-up revealed tumor relapse in eight cases (follow up 6-180 months, median 24). Four patients had local recurrence at 12 to 168 months. Distant metastasis developed at 1 to 6 years in five cases with spread to lung (2 cases), liver (4 cases), and bone. Metastasis or local recurrence developed within 2 years in five patients. To date, no patient has died of their tumor. These findings demonstrate that nuclear atypia, hypercellularity, greater than 4 mitoses/10 HPFs, and necrosis may be seen in up to 10% of extrathoracic SFTs, and are associated with, but are not by themselves predictive of, aggressive clinical behavior. In addition, our findings confirm that the behavior of extrathoracic SFTs is unpredictable, entirely comparable to that of their better known pleural counterparts, and confirm that patients with SFTs in all locations require careful, long-term follow up. It is probably unwise to regard any such lesion as definitely benign.

12E7 Antigen↗