[Unusual intra-abdominal tumor]. / Tumeur intra-abdominale inhabituelle.

Desmoplastic small round cell tumor is a rare poorly differentiated, aggressive neoplasm that most frequently affects the abdominal cavity. The diagnosis is often difficult requiring morphological and immunohistochemical study. The purpose of our study is to clarify the anatomoclinical aspects of this rare tumor and to discuss the approach of the diagnosis and the prognosis. A 18-year old teenager had presented an enormous intra-abdominal mass. The radiologic findings showed a mass for 20 cm in diameter repulsing the liver and the right kidney. A surgical biopsy was performed. Histopathologic examination demonstrated a proliferation of small round cells surrounded by a desmoplastic stroma. Immunohistochemical staining was positive for pancytokeratin (KL1), epithelial membrane antigen (EMA), vimentin, neuron specific enolase (NSE) and desmine; thus, the diagnosis of a desmoplastic small round cell tumor was made. The patient received a first chemotherapy followed by a maximal surgical reduction. A local recurrence and bone metastasis occurred and the patient eventually died 18 months after the diagnosis from hepatic failure. The diagnosis of desmoplastic small round cell tumor may be suspected in young patient presenting an intra-abdominal small round cell tumor. The treatment is multidisciplinary and its prognosis is poor.

[Contribution of Western blotting to the diagnosis of hydatidosis]. / Apport de la technique Western blot dans le diagnostic de l'hydatidose.

The aim of this study is to evaluate the contribution of the immunoWesternblot for the diagnosis and the post surgical follow-up of the hydatidosis. 71 sera from patients with hydatidosis confirmed by surgery were studied. All had a negative hydatic serology by screening tests (enzyme-linked immunosorbent assay, hemagglutination, electrosyneresis). 12 patients with sera in pre and post operative were monitored for 2 years. The Echinococcus Western blot IgG permitted to rectify the diagnosis of hydatidosis in 67.6 %. The rate of positivity was 100 % for the multivesicular liver cysts, 60 % for the young cysts and 50 % for the calcified cysts. Western blot permitted to rectify the diagnosis of lung cysts in 62.5 % of cases and in 50 % of cranial-spinal localizations. Analysis of Western Blot evolution in the 12 patients followed in pre and post-surgical revealed the disappearance of the bands 16, 18 and 26-28kDa in 8 month in the 8 patients with complete exeresis. This study proved the value added of Western blot compared to the other traditional techniques for the immunodiagnostic and the post-surgical monitoring of hydatidosis.

Diagnosis of human hydatidosis: comparison between imagery and six serologic techniques.

Echography and/or chest radiograph in association with six serologic (immunologic) methods were tested for their ability to diagnose human hydatidosis. The immunologic techniques used were latex agglutination, counter immunoelectrophoresis, enzyme-linked immunosorbent assay (ELISA) with whole hydatid fluid and with antigen 5, a thermobabile lipoprotein that elicits the arc 5 precipitin line in immunoelectrophoresis. In this report, the results of examinations of 273 patients are presented. Of these, 243 cases were surgically proven to have hydatidosis, whereas 30 of the 273 that were strongly suspected of having hydatid cysts by radiology were shown to have other pathologies. The ELISA was more sensitive than the other methods, with 204 of 243 sera shown to be positive. The remaining 39 sera that gave false-negative results were tested using two recently developed methods, enzyme-linked immunoelectrodiffusion assay (ELIEDA) and immunoblotting (electrophoretic migration of hydatid fluid antigens under denaturing but nonreducing conditions, blotting, and immunoenzymatic assay). Immunoblotting, using our experimental conditions, had a greater sensitivity than the ELIEDA with this technique. Four of 37 sera showed one to three bands of 65, 12, and 8 kD. The sensitivity of the ELISA did not increase with either the size or type of cyst. Comparison of radiology with serology confirmed a good correlation between the two methods. Nevertheless, serology is more specific but less sensitive than imagery.