Masahumi Ito

Distribution of S-100b protein in normal salivary glands and salivary gland tumors

Immunohistochemical studies were performed for the presence of S-100b protein in non-neoplastic and neoplastic salivary gland tissues by the peroxidase anti-peroxidase (PAP) method. Some cases of pleomorphic adenoma were investigated by immuno-electron microscopy. S-100b protein could not be detected in epithelial cells of intercalated ducts, acini, striated ducts and excretory ducts of non-neoplastic salivary gland. However, myoepithelial cells surrounding the acini and intercalated ducts were specifically stained by S-100b protein. In pleomorphic adenomas, S-100b protein-positive cells could be mostly observed in the myxoid and chondroid areas, and the basal layer cells of the double-layered ductal cells were also positive. In clear cell adenoma, the clear cells were also S-100b protein positive. In adenoid cystic carcinomas, S-100b protein-positive cells could be found in trabecular areas, but not in tumor cells showing cribriform-pattern. In other tumors (Warthins tumor, oxyphilic adenoma, basal cell adenoma, mucoepidermoid tumor and acinar cell carcinoma), S-100b protein positive cells were seldom observed. Immuno-electron microscopically, S-100b protein was diffusely distributed in the cytoplasm of myoepithelial cells as well as of tumor cells of pleomorphic adenoma, being distributed especially on the membrane of endoplasmic reticulum and the outer nuclear membrane.

THREE CASES OF PRIMARY SPLENIC LYMPHOMA

Three cases of primary splenic lymphoma (two diffuse large cell (DL) lymphomas; and one follicular mixed small cleaved and large cell (FM) lymphoma according to the Working Formulation) are presented. Histologically as well as immuno‐histochemically, all were considered to be of follicular center cell origin. Reticulin stains clearly demonstrated that the white pulp was primarily involved both in FM and DLs. Remnants of clusters of dendritic reticular cells were demonstrated immuno‐histochemically in one case of DL. Primary splenic lymphomas in the Japanese literatures were reviewed and compared with those in the American literatures. It was found that “a solitary mass” was the predominant gross feature (81%) and “reticulum cell sarcoma” was the predominant histologic type (66%) in Japan. In the United States, lymphosarcoma was the predominant histologic type (39%), reflecting the histologic distribution of nodal lymphomas, and “homogeneous” or “miliary” was the predominant gross feature (71%). ACTA PATHOL. JPN. 35: 419–435, 1985.

Recurrent MYB rearrangement in blastic plasmacytoid dendritic cell neoplasm

Lymphoproliferative Disorders Team, Centre de Recherche des Cordeliers, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Centre de Recherche des Cordeliers, Paris, France; Service d’Hématologie Biologique, GH Pitié-Salpêtrière, Paris, France; Service de Biostatistique et Informatique Médicale, Hôpital Saint Louis, Paris, France.; Département de génétique, GH Pitié-Salpêtrière, Paris, France; INSERM U1170, Institut Gustave Roussy, Villejuif, France; Département d’Hématologie, Hôpital Becquerel, Rouen, France; Pôle d’Hématologie, Hôpital Brabois, Vandoeuvre-les-Nancy, France; Service d’Hématologie Clinique, Hôpital d’Argenteuil, Argenteuil, France and Karyopharm Therapeutics, Newton, MA, USA E-mail: santos.susin@crc.jussieu.fr or florence.nguyen-khac@psl.aphp.fr These authors contributed equally to this work. Senior coauthorship.

Basic fibroblast growth factor-heparan sulphate complex in the human dialysis-related amyloidosis

A major constituent of the amyloid fibrils in dialysis-related amyloidosis is β2-microglobulin (β2-MG). Heparan sulphates (HS) co-localize with the amyloid fibrils and monocytes/macrophages are commonly found around amyloid deposits, but the role of HS in amyloidogenesis is not yet defined. HS have variable saccharide sequences and can interact specifically with basic fibroblast growth factor (bFGF), a potent chemotactic factor for the monocyte/macrophage. The present investigation was undertaken to look for a functional link between co-localized HS and the pathogenesis of dialysis-related amyloidosis. Using amyloid-enriched ligament, immunohistochemical localization was tested for β2-MG, endogenous bFGF, and bFGF-binding portions of HS. For the detection of bFGF-binding portions of HS, the ligament sections were incubated with exogenous bFGF and then with anti-bFGF antibody. The specificity of the interaction between bFGF and HS was established by confirming a concomitant loss of immunoreactivity during selective removal of HS with heparitinase. β2-MG, endogenous bFGF, and bFGF-binding portions of HS were detected between bundles of collagen. Endogenous bFGF and bFGF-binding portions of HS were not detected in more advanced amyloid lesions, whereas β2-MG and other portions of HS were detected. We propose that β2-MG, endogenous bFGF, and bFGF-binding portions of HS form a complex and localize in the early amyloid lesions of dialysis-related amyloidosis.