Giant Intra-Articular Extrasynovial Osteochondroma of the Knee: A Report of Two Cases

We report two cases of a giant extrasynovial osteochondroma of the knee located in the infrapatellar fat pad region, in two females who were 58 and 71 years old respectively. Both patients had noticed the mass many years before our first clinical observation. In both patients, at physical examination a solid, firm and hard mass was palpable in the anterior part of the knee in Hoffa’s fat pad region, and the range of motion of the knee was severely restricted and painful. CT scan examination with 3D-reconstruction showed two large, calcified neoformations behind the patellar tendon, between the apex of the patella and the proximal third of the tibia. In both cases, the mass was completely resected surgically through an anterior longitudinal approach. At histological examination, the excised masses consisted of an outer layer of hyaline cartilage without significant chondrocyte atypia and an inner region of bone trabeculae formed by endochondral ossification. At follow-up, 8 and 4 years after the operation, both patients were pain-free, with complete recovery of the range of motion of the knee and without any clinical or radiographic evidence of recurrence. The authors believe that intra-articular extrasynovial osteochondroma of the knee is a primary metaplasia of Hoffa’s fat pad. Usually, the tumor develops slowly and asymptomatically over many years. The treatment of choice is a marginal resection of the mass, although a biopsy should be considered in some cases. Recurrences are extremely rare

Extra-osseous osteochondroma-like soft tissue mass of the patello-femoral space

BACKGROUND: Extraskeletal cartilaginous tumors are uncommon. Osteochondromas usually arise from the metaphyseal region of the growing skeleton. CASE PRESENTATION: A 53 year old man presented with a three years history of anterior knee pain and inability to flex his knee more than 90°. Clinical examination and imaging studies revealed a nodular calcific mass in the anterior portion of the knee, displacing the medial portion of the patellar tendon. Following excision, histopathology confirmed the diagnosis of extra-osseous osteochondroma-like soft tissue mass, with no recurrence 24 months after surgery. CONCLUSION: An integrated clinical-pathologic diagnosis helps to clarify the nature of extraskeletal cartilaginous tumors that can arise at unusual anatomic site. Complete local surgical excision is the management of choice

Multiple Histone Methyl and Acetyltransferase Complex Components Bind the HLA-DRA Gene

Major histocompatibility complex class II (MHC-II) genes are fundamental components that contribute to adaptive immune responses. While characterization of the chromatin features at the core promoter region of these genes has been studied, the scope of histone modifications and the modifying factors responsible for activation of these genes are less well defined. Using the MHC-II gene HLA-DRA as a model, the extent and distribution of major histone modifications associated with active expression were defined in interferon-γ induced epithelial cells, B cells, and B-cell mutants for MHC-II expression. With active transcription, nucleosome density around the proximal regulatory region was diminished and histone acetylation and methylation modifications were distributed throughout the gene in distinct patterns that were dependent on the modification examined. Irrespective of the location, the majority of these modifications were dependent on the binding of either the X-box binding factor RFX or the class II transactivator (CIITA) to the proximal regulatory region. Importantly, once established, the modifications were stable through multiple cell divisions after the activating stimulus was removed, suggesting that activation of this system resulted in an epigenetic state. A dual crosslinking chromatin immunoprecipitation method was used to detect histone modifying protein components that interacted across the gene. Components of the MLL methyltransferase and GCN5 acetyltransferase complexes were identified. Some MLL complex components were found to be CIITA independent, including MLL1, ASH2L and RbBP5. Likewise, GCN5 containing acetyltransferase complex components belonging to the ATAC and STAGA complexes were also identified. These results suggest that multiple complexes are either used or are assembled as the gene is activated for expression. Together the results define and illustrate a complex network of histone modifying proteins and multisubunit complexes participating in MHC-II transcription

The clinicopathologic observation, c-KIT gene mutation and clonal status of gastrointestinal stromal tumor in the sacrum

<p>Abstract</p> <p>Background</p> <p>It is very rare that gastrointestinal stromal tumor (GIST) occurs in the sacrum. Only one case of GIST occuring in the sacral region, with intracranial metastasis, has been reported in the literature. Moreover, only few cases have been published in literature about its clonal origin.</p> <p>Case presentation</p> <p>In this report, we present a rare case of GIST occuring in the sacrum and describe its clinicopathologic features, c-KIT gene mutation and clonal status. Microscopically, the lesion was composed of spindle cells arranged in cords, knitted and whirlpool patterns. Trabecula of bone were found in the lesion. The cytoplasm of tumor cells were abundant, and the nuclei were fusiform. Mitotic figures were rare. Immunohistochemically, the tumor cells showed positive reactivity for CD117 and CD34. On mutation analysis, a c-KIT gene mutation was found in exon 11. The result of clonal analysis demonstrated that the GIST was monoclonal.</p> <p>Conclusion</p> <p>In summary, we showed that tumor material, phenotypically identical with GISTs was found in the sacrum. It is difficult to differentiate GISTs from other spindle cell tumors, hence the need for immunohistochemistry, the examination of c-KIT gene amplification and sequencing.</p

Primary omental Gastrointestinal stromal tumor (GIST)

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A gastrointestinal stromal tumor with mesenteric and retroperitoneal invasion

<p>Abstract</p> <p>Background</p> <p>Gastrointestinal stromal tumors are rare visceral sarcomas arising in the gastrointestinal tract wall. In this report we present a case of gastrointestinal stromal tumors with mesenteric and retroperitoneal invasion, describe and discuss its computed tomography findings.</p> <p>Case presentation</p> <p>A 57-years-old male patient has been complaining of abdominal distention, weight lose, and hematuria. During physical examination, significant distention and multiple palpable tumor masses were identified on the abdomen. Abdominal computed tomography showed multiple, well-defined, soft tissue masses with homogenous and heterogeneous pattern, in the mesenteric and retroperitoneal areas. Unlike specific features of gastrointestinal stromal tumor, renal obstruction and atypical central calcification without chemotherapy that has not been yet described were seen in this case. Computed tomography did not reveal liver metastases and/or the lymph nodes with pathological size. Ultrasonography-guided true-cut^®biopsy was made, histopathologic and immunohistochemical analyses demonstrated stromal tumor which, C-KIT (+). The patient underwent left ureterectomy, left nephrectomy and total colectomy. Postoperative histopathological analyses revealed lower grade malignant GISTs. As of 17 months after the surgery, he is alive and free of recurrence.</p> <p>Conclusion</p> <p>When intraabdominal, multiple, large (>5 cm), well-circumscribed, homogenous or heterogeneous mass lesions without ascites, omental caking and lymph nodes metasteses were seen, gastrointestinal stromal tumors should be considered in the differential diagnosis.</p

Mary Adams and the producer’s role in early BBC science broadcasts

Mary Adams was a science producer at the BBC from 1930–6. She is shown to have played a crucial role in shaping science broadcasts, in particular devising formats and styles of presentation. However, her approach is shown to have been primarily motivated by broadcasting considerations rather than by the popularisation of science. Through her interaction with scientists she helped to construct a new professional domain, that of the science-broadcasting professional, at a time when other producers were creating analogous roles in other areas of broadcasting. This paper is based largely on unpublished archival documents

Serotonin Augments Gut Pacemaker Activity via 5-HT3 Receptors

Serotonin (5-hydroxytryptamine: 5-HT) affects numerous functions in the gut, such as secretion, muscle contraction, and enteric nervous activity, and therefore to clarify details of 5-HT's actions leads to good therapeutic strategies for gut functional disorders. The role of interstitial cells of Cajal (ICC), as pacemaker cells, has been recognised relatively recently. We thus investigated 5-HT actions on ICC pacemaker activity. Muscle preparations with myenteric plexus were isolated from the murine ileum. Spatio-temporal measurements of intracellular Ca2+ and electric activities in ICC were performed by employing fluorescent Ca2+ imaging and microelectrode array (MEA) systems, respectively. Dihydropyridine (DHP) Ca2+ antagonists and tetrodotoxin (TTX) were applied to suppress smooth muscle and nerve activities, respectively. 5-HT significantly enhanced spontaneous Ca2+ oscillations that are considered to underlie electric pacemaker activity in ICC. LY-278584, a 5-HT3 receptor antagonist suppressed spontaneous Ca2+ activity in ICC, while 2-methylserotonin (2-Me-5-HT), a 5-HT3 receptor agonist, restored it. GR113808, a selective antagonist for 5-HT4, and O-methyl-5-HT (O-Me-5-HT), a non-selective 5-HT receptor agonist lacking affinity for 5-HT3 receptors, had little effect on ICC Ca2+ activity. In MEA measurements of ICC electric activity, 5-HT and 2-Me-5-HT caused excitatory effects. RT-PCR and immunostaining confirmed expression of 5-HT3 receptors in ICC. The results indicate that 5-HT augments ICC pacemaker activity via 5-HT3 receptors. ICC appear to be a promising target for treatment of functional motility disorders of the gut, for example, irritable bowel syndrome