[Solitary fibrous tumors and hemangiopericytomas of the meninges: Immunophenotype and histoprognosis in a series of 17 cases]. / Tumeurs fibreuses solitaires et hémangiopéricytomes des méninges : immunophénotype et évaluation du grade histopronostique dans 17 cas.

INTRODUCTION: The 2007 World Health Organization (WHO) classification of tumors of the central nervous system distinguishes meningeal hemangiopericytomas (HPC) from solitary fibrous tumors (TFS). In the WHO classification of tumors of soft tissue and bone, those neoplasms are no longer separate entities since the discovery in 2013 of a common oncogenic event, i.e. the NAB2-STAT6 gene fusion. A shared histopronostic grading system, called "Marseille grading system", was recently proposed, based on hypercellularity, mitotic count and necrosis. We evaluated the immunophenotype and histoprognosis in a retrospective cohort of intracranial HPC and TFS. METHODS: Fifteen initial tumors and 2 recurrences were evaluated by immunohistochemistry for STAT6, CD34, EMA, progesterone receptors and Ki67. The pronostic value of the WHO and the Marseille grading systems was tested on 12 patients with clinical follow-up. RESULTS: Initial tumors were 11 HPC and 4 SFT. STAT6 and CD34 were expressed in 16/17 tumors, EMA and progesterone receptors in 2 and 5 cases, respectively. The Ki67 labelling index was 6.25% in HPC and 3% in SFT. Half of the tumors recurred between 2 years and 9 years after initial diagnosis (mean time 5 years). No statistical difference in the risk of recurrence was associated with either grade (WHO or Marseille), in this small cohort. CONCLUSION: The diagnosis of HPC and TFS is facilitated by the almost constant immuno-expression of STAT6, and this justifies their common classification. The high rate of recurrence implies a very long-term follow-up because the current grading systems do not accurately predict the individual risk.

[KHSV/EBV associated germinotropic lymphoproliferative disorder: a rare entity, case report and review of the literature]. / Lymphoprolifération germinotrope HHV8+/EBV+ : une entité rare, à propos d'un cas et revue de la littérature.

We report a case of KSHV/EBV associated germinotropic lymphoproliferative disorder (LPG) in a 49-year-old African patient, without immunosuppression. LPG is a rare entity arising in immunocompetent patients in opposition to other lymphoproliferative disorders associated to Kaposi sarcoma-associated herpes virus (KSHV). The disease presents itself as localized lymphadenopathy with an infiltration of germinal centers by plasmablastic cells coinfected by KSHV and EBV (Epstein-Barr Virus). After treatment, the outcome is favorable. Differential diagnosis in our case, due to the presence of clusters of Hodgkin-like cells in the mantle zone, included lymphocyte rich classic Hodgkin lymphoma (LHCRL) and nodular lymphocyte predominant Hodgkin lymphoma (LHNPL). Finally, we highlight the differential diagnostic criteria of KSHV lymphoproliferative diseases.

ERG expression in prostate cancer: the prognostic paradox.

BACKGROUND: TMPRSS2/ERG fusion resulting in ERG overexpression occurs in 30 to 50% of prostate cancer (PCa) in Caucasian patients, but its prognostic relevance remains controversial. In the present study, we investigated ERG expression in all stages of PCa progression, and evaluated the prognostic impact of ERG status in clinically localized PCa (CLC) and in castration resistant disease (CRPC). METHODS: ERG and AR expressions were evaluated by immunohistochemistry on tissue microarrays containing samples of high grade PIN (n = 57), CLC surgically treated (n = 299, including 185 Caucasians and 114 African-Caribbeans), metastases (n = 17), and CRPC (n = 41). RESULTS: In Caucasians, ERG expression significantly increased from high grade PIN (17.5%) to pT2 (27%) and pT3 CLC (43%), then to metastases (53%). In CLC, stainings for ERG and AR were correlated, and ERG expression was less frequent in African-Caribbeans compared to Caucasians (11.5% vs. 33%). In Caucasians CLC, ERG was associated with longer recurrence free survival, after adjusting for classical prognostic markers. In CRPC, ERG was expressed in 29% of cases, and was associated with a longer overall survival. CONCLUSIONS: Our results confirm that ERG expression is less frequent in PCa from patients of African descent. Although ERG expression increases during PCa natural history, positive ERG status is associated with better outcome in both CLC and CRPC. This paradox could be explained in part by the fact that ERG expression is AR dependant, then ERG positive cancers are likely to progress in a rich androgen environment, with a better response to androgen suppression.