Jean Philippe Merlio

Expression of neurotrophins and their receptors in human bone marrow.

The expression of neurotrophins and their receptors, the low-affinity nerve growth factor receptor (p75LNGFR) and the Trk receptors (TrkA, TrkB, and TrkC), was investigated in human bone marrow from 16 weeks fetal age to adulthood. Using reverse transcription-polymerase chain reaction, all transcripts encoding for catalytic and truncated human TrkB or TrkC receptors were detected together with trkAI transcripts, whereas trkAII transcripts were found only in control nerve tissues. Transcripts for the homologue of the rat truncated TrkC(ic113) receptor were identified for the first time in human tissue. Stromal adventitial reticular cells were found immunoreactive for all neutrophin receptors. In contrast, hematopoietic cell types were not immunoreactive for p75LNGFR but showed immunoreactivity for one or several Trk receptors. TrkA immunoreactivity was found in immature erythroblasts. Catalytic TrkB immunoreactivity was observed in eosinophilic metamyelocytes and polymorphonuclear cells. Truncated TrkB immunoreactivity was found in erythroblasts and megacaryocytes. Immunoreactivity for both catalytic and truncated TrkC receptor was observed in promyelocytes, myelocytes, some polymorphonuclear cells and megacaryocytes. Neutrophin transcript levels appeared higher at fetal than at adult stages, no variation in Trk family transcript levels was observed. The local expression of neurotrophin genes suggests a wide range of paracrine and/or autocrine mode of action through their corresponding receptors within the bone marrow.

IGHV gene features and MYD88 L265P mutation separate the three marginal zone lymphoma entities and Waldenström macroglobulinemia/lymphoplasmacytic lymphomas

To clarify the relationships between marginal zone lymphomas (MZLs) and Waldenström macroglobulinemia/lymphoplasmacytic lymphomas (WM/LPLs), immunoglobulin heavy chain variable gene (IGHV) features were analyzed and the occurrence of MYD88 L265P mutations was identified in a series of 123 patients: 53 MZLs from the spleen (SMZLs), 11 from lymph nodes (NMZLs), 28 mucosa-associated lymphatic tissue (MALT) lymphomas and 31 WM/LPLs. SMZLs were characterized by overrepresentation of IGHV1–2 gene rearrangements with a canonical motif, without selection pressure and with long CDR3 segments. NMZLs had increased frequencies of IGHV3 genes. The IGHV gene was unmutated in most cases, often with long CDR3 segments. MALT lymphomas were usually associated with a mutated IGHV gene, but with the absence of selection pressure. WM/LPLs were associated with an IGHV3–23 overrepresentation and high IGHV mutation rate, with features of selection pressure and short CDR3 segments. MYD88 L265P mutations were almost restricted exclusively to WM/LPL patients. Taken all diagnoses together, all patients with MYD88 L265P mutations had an immunoglobulin M peak and almost all patients except one had bone marrow infiltration. These results demonstrate that the history of antigen exposure of the four entities studied was different and MYD88 L265P was specifically associated with WM/LPLs. WM/LPL may thus be functionally associated with constitutive nuclear factor-κB activation.

Statistical evaluation of diagnostic and prognostic features of CD30+ cutaneous lymphoproliferative disorders : A clinicopathologic study of 65 cases

Several clinical and histopathologic features of 65 CD30+ cutaneous lymphoproliferations were evaluated for their diagnostic value between CD30+ primary versus secondary cutaneous lymphomas and for their prognostic significance. Primary cutaneous disease, spontaneous regression, and absence of extracutaneous spreading (but not age < or =60 years) were associated with a better prognosis. Epithelial membrane antigen, BNH9, CD15 or CBF.78 antigen were expressed in all types of cutaneous lymphoproliferations. However, epithelial membrane antigen immunoreactivity was more frequently expressed in CD30+ secondary cutaneous large-cell lymphoma. Among CD30+ primary cutaneous large-cell lymphoma, CD15 expression was only seen in localized skin lesions. P53 expression was not associated with spontaneous regression, extracutaneous spreading, or survival. Nested reverse transcriptase-polymerase chain reaction allowed the detection of NPM-ALK transcripts in 10 of 26 CD30+ primary and in 3 of 11 secondary cutaneous large-cell lymphomas. The ALK protein was detected in only 1 of 50 primary and in 4 of 15 secondary cutaneous CD30+ lymphoproliferations. In CD30+ primary cutaneous lymphoproliferation, NPM-ALK transcripts might be expressed by very rare normal or tumoral cells that are undetectable by immunohistochemistry. However, the expression of either NPM-ALK transcripts or ALK-protein was not correlated with prognosis or age in CD30+ cutaneous lymphoproliferations.

Agnogenic Myeloid Metaplasia, Portal Hypertension, and Sinusoidal Abnormalities

A patient with agnogenic myeloid metaplasia suffered from gastrointestinal bleeding due to ruptured esophageal varices. The portal vein and its intrahepatic branches were patent. Except for the presence of myeloid cells, mainly megakaryocytes, in the sinusoids, liver histology was more or less normal. However, on Sirius red staining there was marked perisinusoidal fibrosis. In addition to numerous collagen bundles in the Disse space, electron microscopy also revealed the presence of hemopoietic cells, the transformation of perisinusoidal cells into fibroblasticlike or myofibroblasticlike cells, or both, and fragmentary deposits of basement membrane-like material. In the pathogenesis of sinusoidal hypertension as it occurs in agnogenic myeloid metaplasia, all the factors mentioned above should probably be taken into consideration.

High resolution SNP array genomic profiling of peripheral T cell lymphomas, not otherwise specified, identifies a subgroup with chromosomal aberrations affecting the REL locus

Little is known about genomic aberrations in peripheral T cell lymphoma, not otherwise specified (PTCL NOS). We studied 47 PTCL NOS by 250k GeneChip single nucleotide polymorphism arrays and detected genomic imbalances in 22 of the cases. Recurrent gains and losses were identified, including gains of chromosome regions 1q32–43, 2p15–16, 7, 8q24, 11q14–25, 17q11–21 and 21q11–21 (≥5 cases each) as well as losses of chromosome regions 1p35–36, 5q33, 6p22, 6q16, 6q21–22, 8p21–23, 9p21, 10p11–12, 10q11–22, 10q25–26, 13q14, 15q24, 16q22, 16q24, 17p11, 17p13 and Xp22 (≥4 cases each). Genomic imbalances affected several regions containing members of nuclear factor‐kappaB signalling and genes involved in cell cycle control. Gains of 2p15–16 were confirmed in each of three cases analysed by fluorescence in situ hybridization (FISH) and were associated with breakpoints at the REL locus in two of these cases. Three additional cases with gains of the REL locus were detected by FISH among 18 further PTCL NOS. Five of 27 PTCL NOS investigated showed nuclear expression of the REL protein by immunohistochemistry, partly associated with genomic gains of the REL locus. Therefore, in a subgroup of PTCL NOS gains/rearrangements of REL and expression of REL protein may be of pathogenetic relevance.

Primary Digestive Richter's Syndrome

The clinical and morphologic transformation of 3 to 5% of chronic lymphocytic leukemia (CLL) to diffuse large-cell lymphoma (DLCL) is commonly referred to as Richters syndrome. Richters syndrome occurs mostly in lymph nodes and may represent a second neoplasm or a transformation from the same clonal population. Clinical features in six patients with digestive Richters syndrome were recorded. Paired samples of CLL and DLCL were investigated by immunohistological analysis (n = 6) and by polymerase chain reaction (PCR) for immunoglobulin heavy-chain gene rearrangement (n = 4). Histological examination revealed the involvement of the gastrointestinal tract by DLCL of B-cell phenotype (n = 6). The same monoclonal rearrangement between CLL and DLCL was demonstrated by PCR and sequencing analyses in two patients. The monoclonal rearrangement was different between CLL and DLCL in only one case. Median survival was 22 months for five patients receiving chemotherapy, suggesting that digestive Richters syndrome has a better prognosis than nodal Richters syndrome. Indeed, appropriate surgical resection combined with chemotherapy led to partial or complete remission in four patients.

Low prevalence of monoclonal B cells in Helicobacter pylori gastritis patients with duodenal ulcer.

We have studied the prevalence of B-cell clonality among a large group of 320 patients with Helicobacter pylori gastritis and duodenal ulcer. These patients underwent endoscopic examination with multiple gastric biopsies at diagnosis and were followed 2 and 12 months after therapy. Histopathologic examination of 809 sets of biopsy specimens showed lymphoid gastritis with lymphoid aggregates or follicles, but without lymphoepithelial lesion, in 302 samples corresponding to initial biopsy specimens (n=130) or to posttreatment biopsy specimens (n=172). DNA extracted from fresh antral specimens allowed the amplification of Helicobacter pylori DNA in all cases before therapy. The arrangement of the immunoglobulin heavy chain gene was studied by polymerase chain reaction (PCR) in the 302 selected lymphoid gastritis samples. Single or dominant bands were seen only in four specimens from three patients (1.3%), whereas a polyclonal pattern was seen in the other 298 samples. The detection threshold of our PCR technique was approximately 3% of clonal B cells diluted in a polyclonal population. This threshold appeared to be a reliable cutoff between polyclonal gastritis and clonal MALT lymphoma. In our experience, Helicobacter pylori lymphoid gastritis appeared mainly as a benign polyclonal condition.

The detection of Tel–TrkC chimeric transcripts is more specific than TrkC immunoreactivity for the diagnosis of congenital fibrosarcoma

The t(12;15)(p13;q25) translocation, a recurrent chromosomal abnormality of congenital fibrosarcoma, leads to the expression of a Tel–TrkC fusion transcript. To determine whether detection of the chimeric protein may be helpful for the diagnosis of congenital fibrosarcoma, immunohistochemistry was performed with an anti‐TrkC antibody on 26 spindle cell tumours of newborn or young children (n=19) or adults (n=7). Four out of five congenital fibrosarcomas showed TrkC immunoreactivity with cytoplasmic paranuclear staining. However, TrkC immunoreactivity was not restricted to congenital fibrosarcoma and was observed in infantile myofibromatosis, congenital haemangiopericytoma, desmoid tumour, nodular fasciitis, fibrous hamartoma, inflammatory myofibroblastic tumour, and adult fibrosarcoma. RT‐PCR analysis was performed on nine cases, including four congenital fibrosarcomas, for which frozen material was available. Tel–TrkC transcripts were detected by RT‐PCR in the four congenital fibrosarcomas analysed, but not in the five other spindle cell tumours. Furthermore, several Tel–TrkC transcripts encoding for kinase isoforms of the Tel–TrkC protein were detected in congenital fibrosarcoma and may be involved in oncogenesis. The reciprocal TrkC–Tel transcript was detected in only one congenital fibrosarcoma. While the detection of a Tel–TrkC fusion transcript is a recurrent feature of congenital fibrosarcoma, TrkC immunoreactivity does not appear specific for the diagnosis of fibromatous paediatric tumours. Copyright

Bone Marrow Histopathologic and Molecular Staging in Epidermotropic T-Cell Lymphomas

This study was undertaken to determine the prognostic value of bone marrow histopathologic and molecular analyses in 53 patients with mycosis fungoides and 7 with Sézary syndrome. Bone marrow was involved in only 1 patient with Sézary syndrome, clinical stage IVA, before bone marrow biopsy. An ambiguous T-cell infiltrate was observed in 8 patients but was not associated with disease progression. The bone marrow specimen was normal in 51 patients. Monoclonality was detected in the skin specimen in 44 cases; an identical T-cell clone in the blood specimen was found in 21 of them and, in 16 of the 21 patients, in bone marrow specimens without histologic correlation. Multivariate analysis confirmed that clinical stage and detection by polymerase chain reaction of an identical T-cell clone in skin and blood specimens had an independent prognostic value. No further prognostic value was observed for the presence of a T-cell clone in bone marrow specimens. Our data do not support the need for bone marrow examination in patients with mycosis fungoides/Sézary syndrome.

Value of Interphase FISH for the Diagnosis of t(11;14)(q13;q32) on Skin Lesions of Mantle Cell Lymphoma

The diagnosis of skin lesions of mantle cell lymphoma (MCL) may be difficult at the onset of the disease. We observed 2 patients with papules of the trunk and 1 with diffuse infiltration of the trunk and the face and 2 subcutaneous nodules. Skin samples showed diffuse infiltration of the dermis (n = 1) or perivascular infiltration (n = 2). The infiltrate corresponded to centrocytic cells (n = 2) or pleomorphic blastoid cells (n = 1) with a B-cell phenotype: CD3-, CD5+ (2/3), CD20+, CD23-, and CD43+. In only 1 case was cyclin D1 immunoreactivity detected, and the t(11;l4)(q13;q32) breakpoint was amplified from both lymph node and skin DNA. Competitive reverse transcriptase-polymerase chain reaction was not contributive for skin specimens. In all 3 cases, interphase fluorescence in situ hybridization (FISH) demonstrated t(11;14) fusion signals either on paraffin sections or on fresh frozen touch preparations of skin biopsies. The recognition of skin lesions of MCL from other B-cell infiltrates can be established by interphase FISH.