[Pelvic hydatid cyst: differential diagnosis with a bacterial abscess with cutaneous fistula]. / Kyste hydatique pelvien : diagnostic différentiel d'un abcès bactérien fistulisé

The genus Echinococcus is a worldwide tapeworm with a two host mammalian cycle. Among the six described species, Echinococcus granulosus (EG) and Echinococcus multilocularis are the most important in respect to their public health importance. Infected human, as an intermediate accidental host, presents single to several cysts, mainly located in the liver. We are describing the clinical, radiological and histological findings of a woman born in Morocco, recently arrived in France and presenting a pelvic hydatid cyst. The misknowledge of such a diagnosis conducted to initial surgery and thus a risk of further metastasised lesions. We are suggesting that any hypoechogenic pelvic lesion in a patient originated from a Mediterranean country should be considered as a pelvic localization of EG.

Hairy cell leukemia. Diagnosis of bone marrow involvement in paraffin-embedded sections with monoclonal antibody DBA.44.

The new monoclonal antibody DBA.44 recognizes an unknown fixation-resistant B-cell differentiation antigen expressed by mantle zone lymphocytes, reactive immunoblasts, monocytoid B cells, and a small proportion of high- and low-grade lymphomas. Among node-based lymphomas, the strongest membrane staining was observed in centroblastic, immunoblastic, and monocytoid B-cell lymphomas. In studying bone marrow biopsy specimens from 166 patients with hairy cell leukemia, strong positive staining of surface membrane 'hairy' features of leukemic cells was observed in routinely fixed and decalcified bone marrow biopsy specimens of nearly all cases. The antibody distinguished hairy cell leukemia from the more common B-cell chronic lymphocytic leukemia and bone marrow infiltrates of typical lymph node-based lymphomas by immunomorphologic criteria. DBA.44 was valuable to (1) confirm the diagnosis of hairy cell leukemia, (2) estimate the bone marrow density of hairy cell leukemia before and after treatment, and (3) make the diagnosis of hairy cell leukemia in ambiguous cases, which are all properties that indicate its usefulness in the practice of diagnostic hematopathology.

Production of anti-B monoclonal antibodies (DBB.42, DBA.44, DNA.7, and DND.53) reactive on paraffin-embedded tissues with a new B-lymphoma cell line grafted into athymic nude mice.

A new B-lymphoma cell line (DEAU-cell line) was established from a diffuse large-cell lymphoma (centroblastic type) and was successfully grafted in athymic nude mice. Monoclonal antibodies (MoAbs) were generated using splenocytes of DEAU-tumor bearing mice. Before the fusion experiments, cellular immunity of the mice bearing growing DEAU tumors was restored by injection of spleen cells from conventional Balb/C mice. Spleen cells from conventional Balb/C mice immunized with DEAU-cell line were also used for the generation of MoAbs. Four MoAbs (DBB.42 and DBA.44 from normal Balb/C mice, and DNA.7 and DND.53 from athymic nude mice) were investigated because they identified B-cell-associated antigens not destroyed by fixatives. DBB.42 recognized a pan-B cell-associated antigen (molecular weight (mol wt) = 45 Kd). DBA.44 detected a B-cell antigen (mol wt not determined) expressed on a subpopulation of B lymphocytes in the mantle zone of lymphoid follicles. DNA.7 also defined a B-cell antigen (43 Kd) mainly expressed on germinal center cells. Similarly, DND.53 recognized a B-cell antigen (two bands of mol wt 20 Kd and 35 Kd, respectively) mainly expressed on germinal center cells and mantle zone lymphocytes and interdigitating reticulum cells in the paracortical area. Major differences were found in the reactivities of these MoAbs on malignant lymphomas. DBB.42 was positive with almost all B-cell lymphomas and some T-cell lymphomas. Within the group of low-grade B-cell lymphomas, DBA.44 reacted principally with hairy-cell leukemia. DNA.7 reacted mainly with high-grade B-cell lymphomas with a weak positivity in low-grade B-cell lymphomas. DND.53 reacted with all but one B-cell lymphoma, cells of histiocytosis X, and Reed-Sternberg cells. These findings indicate that new MoAbs can be generated by using spleen cells from athymic mice bearing human tumors as well as by new lymphoid cell lines. The MoAbs so generated, as in the present study, are deemed potentially useful for the recognition of B-cell lymphomas in routine diagnostic histopathology. In addition, DND.53 could be of value for the diagnosis of histiocytosis X and the detection of Reed-Sternberg cells in Hodgkin's disease.