Philippe Fauré

Diagnostic features of primary malignant lymphomas of the thyroid with monoclonal antibodies

Primary malignant lymphomas (ML) of the thyroid are rare and their conclusive morphologic diagnosis is not always possible. The authors report diagnostic features of 11 cases of ML and one case of plasmacytoma of thyroid compared with chronic lymphocytic thyroiditis and undifferentiated carcinomas of thyroid in an immunohistochemical study using monoclonal antibodies (MoAb). The lymphoid nature of tumors could be identified in all cases with three MoAb on paraffin sections. In ML, tumor cells expressed leucocyte common antigen (Dako‐LC+) with negativity for epithelial membrane antigen (Dako‐EMA—) and cytokeratin (KL1—). Newer MoAb identifying B‐cell (LN‐1, LN‐2, MB2) and T‐cell‐associated antigens (MT1, UCHL1) not denatured by fixation, revealed B‐cell nature of tumor cells in all cases of ML. Among anti‐B MoAb, LN‐1 and MB2 were most consistent in their reactivity. In cryostat sections of three ML cases, the tumor cells expressed one or more B‐cell‐associated antigens. Plasmacytoma was negative for Dako‐LC and KL1 but positive for Dako‐EMA and monotypic cytoplasmic Ig.

Immunohistochemical profile of cutaneous B-cell lymphoma on cryostat and paraffin sections

Thirty cases of primary (23 cases) and secondary (seven cases) cutaneous B-cell lymphoma (CBCL) were studied by immunohistochemistry using a selected monoclonal antibody (MoAb) panel on both cryostat and paraffin sections. On cryostat sections all CBCL so tested were positive for surface membrane immunoglobulins (IgMk most often) and B-cell antigens (CD22+, CD37+ ) with a variable T-cell-reactive component identified by MoAbs against T-cell antigens (CD2, CD3, CD4, CD5, CD8). CD4-positive stromal T-cells were usually more numerous than CDS-positive cells. A strong (50–75% of total cells) stromal T-cell (CD2+, CD3+ ) reaction was found in centroblastic-centrocytic lymphoma. Small numbers of CD1+ Langerhans cells were found in most cases, but they were present in large numbers in follicular lymphoma. On paraffin sections, a combination of MoAbs against B-associated antigens (LN-1, MB2) identified B-cell lineage in virtually all cases of CBCL. CBCL was negative for MoAbs against T-associated antigens (MT1, UCHL1) with rare exceptions (two cases). However, MT1 and UCHL1 combined identified the T-cell nature of all cases of nonepidermotropic, nonmycosis T-cell lymphoma, which were initially predictive of B-lineage by histologic pattern.

Évolution paléogéographique de la Tunisie saharienne et atlasique au cours du Jurassique

Abstract By means of palaeontologic data, the differert Jurassic formations of Tunisia are correlated along a north-south transect, from the Saharan Platform to the Northern Atlas, across the successive steps of the South-Tethyan stable palaeomargin. A palaeogeographic synthesis of the country is herein proposed, based on 11 maps established for the most important stages of this preoceanic rifting phase which is characterized by particularly active transtensional tectonics.

Datations et corrélations nouvelles dans les séquences de dépôt du Lias terminal et du Dogger des Corbières (Aude, France) grâce aux Ammonites et aux Brachiopodes

Abstract By means of supplementary datings of new Ammonites and particularly Brachiopods, the stratigraphy of the Uppermost Liassic and Mid-Jurassic carbonates from Corbieres is reviewed with distinction of new depositional sequences and separation in the time of the “calcaires a chaules” (Bouquignan Formation) from the “calcaires a oncolithes” (Feuilla Formation). We also give evidence of the main gap occurring just before the deposition of the Feuilla Formation (lateral pinching out) and, particularly, of the Villedaigne Formation. This last one, Mid-Upper Bathonian in age, overlies either the Bizanet Formation (Toarcian), the Bouquignan Formation (Mid Aalenian to Lower Bajocian) or the Feuilla Formation (Lower Bathonian).

Le genre Prodactylioceras (Ammonitina, Pliensbachien inférieur); Biostratigraphie, paléobiogéographie et modalités évolutives. Description d'une espèce nouvelle: Prodactylioceras aurigeriense nov. SP.

Resume La biostratigraphie des Prodactylioceras est ici precisee.Ce groupe Nord-Ouest europeen bien represente dans le Carixien superieur a la base de la souszone a Figulinum par P. davoei ( Sow. ), apparait des la base de la sous-zone a Capricornus avec deux formes originales a repartitions geographiques limitees et bien distinctes. La premiere P. rectiradiatum ( Wingrave ) caracterise la region anglo-lusitanienne; la seconde est une espece nouvelle: P. aurigeriense essentiellement presente dans la region aquitanoiberique.