[Hyperplasia of the coronoid process: diagnosis and treatment]. / Hyperplasie des Processus coronoideus: Diagnose und Therapie.

STUDY GOAL: As it is an unusual and infrequent clinical entity, hyperplasia of the coronoid process is often overlooked or diagnosed too late. The aim of this study was to characterize the morphology, etiology, and clinical picture of coronoid hyperplasia as well as to discuss its diagnosis and treatment. MATERIALS AND METHODS: All cases of histologically confirmed hyperplasia of the coronoid process treated in our center between 1995 and 2004 were analyzed. Patient data were evaluated with respect to age, gender, clinical symptoms, diagnostic work-up, and treatment. The extracted data were compared to those found in the literature. RESULTS: The study included 14 new cases and 101 cases already published: 96 with bilateral and 19 with unilateral hyperplasia. At the time of diagnosis, the subjects' mean age was 23.7 years. The patients in Bonn were all treated by coronoidectomy and appropriate physiotherapy. An improvement in mouth opening could be achieved in 86% of our patients. CONCLUSIONS: In comparison to the somewhat disappointing results of previously published studies with regard to mouth opening and mandibular mobility, our treatment concept seems to offer the possibility for improvement. Our study emphasizes the significance of three-dimensional CT techniques for diagnosis and surgical planning, the superiority of coronoidectomy over coronoidotomy, and the importance of dynamic physiotherapy to prevent postoperative scar formation.

Ki-S1 and PCNA expression in erythroid precursors and megakaryocytes--a comparative study on proliferative and endoreduplicative activity in reactive and neoplastic bone marrow lesions.

The monoclonal antibody Ki-S1 reacts with a cell proliferation-associated nuclear antigen which is expressed in the G1 through G2/M phases of the cell cycle and is resistant to formalin fixation. We have studied Ki-S1 and PCNA (PC10) immunostaining of erythroid precursors (proliferative activity) and megakaryocytes (endoreduplicative activity) in bone marrow trephine biopsies in a variety of reactive and neoplastic lesions using double immunohistochemistry to identify both cell lineages. A significant increase in Ki-S1 labelling compared with PCNA positivity was found in all conditions studied. In particular, specimens derived from secondary polycythaemia (SP), polycythaemia vera (P. vera), and primary osteomyelofibrosis (OMF), and from splenic tissue with myeloid metaplasia (MM), revealed a disproportionally high labelling index of erythropoiesis, which was not present in chronic myelogenous leukaemia (CML), AIDS, and autoimmune (idiopathic) thrombocytopenia (ITP). Enhancement of Ki-S1 (PCNA) staining in SP and P. vera is in keeping with the relevant increase in erythroid precursor proliferation, but in OMF and MM there is overexpression of both proliferation markers, possibly due to secondary folic acid deficiency, which is known to cause a block in the S-phase of the cell cycle. A significant correlation was observed between the sizes of megakaryocytes and their nuclei with Ki-S1 (and also PCNA) staining. Ki-S1 (and PCNA) labelling of predominantly smaller elements of this lineage supports a hypothesis that the phases of the cell cycle have different durations in the various steps of polyploidization, with a prolongation of G1/G2 at higher ploidy levels.(ABSTRACT TRUNCATED AT 250 WORDS)