Chromosomal imbalances in primary hepatic carcinosarcoma.

Hepatic carcinosarcoma is an infrequent biphasic tumor composed of carcinomatous and sarcomatous elements, harboring an unfavorable prognosis. The developmental origin of both tumor components and possible molecular genetic mechanisms involved in tumorigenesis are still unclear. We report here a case of hepatic carcinosarcoma in a 76-year-old patient. The tumor was surgically resected and examined histopathologically including immunohistochemical staining. Focal hepatocellular differentiation was detected in the carcinomatous components but also in the pleomorphic undifferentiated spindle cells. Comparative genomic hybridization revealed amp 1q, -4q, -5p14pter, -5q13q31, +6p, -6q, -8p12pter, -12p, -13q12q14, -14q in the carcinomatous components, and +6p, -10q25qter, -22q in the sarcomatous components. The common +6p harbors the serum response factor gene encoding a transcription factor involved in cell proliferation, migration, and differentiation, confirmed by immunostaining. Hepatic carcinosarcoma is a tumor with biphasic morphology but possible monoclonal origin, showing advanced tumor progression in the carcinomatous areas.

A randomised, multi-centre, prospective, double blind pilot-study to evaluate safety and efficacy of the non-absorbable Optilene Mesh Elastic versus the partly absorbable Ultrapro Mesh for incisional hernia repair.

BACKGROUND: Randomised controlled trials with a long term follow-up (3 to 10 years) have demonstrated that mesh repair is superior to suture closure of incisional hernia with lower recurrence rates (5 to 20% versus 20 to 63%). Yet, the ideal size and material of the mesh are not defined. So far, there are few prospective studies that evaluate the influence of the mesh texture on patient's satisfaction, recurrence and complication rate. The aim of this study is to evaluate, if a non-absorbable mesh (Optilene Mesh Elastic) will result in better health outcomes compared to a partly absorbable mesh (Ultrapro Mesh). METHODS/DESIGN: In this prospective, randomised, double blind study, eighty patients with incisional hernia after a midline laparotomy will be included. Primary objective of this study is to investigate differences in the physical functioning score from the SF-36 questionnaire 21 days after mesh insertion. Secondary objectives include the evaluation of the patients' daily activity, pain, wound complication and other surgical complications (hematomas, seromas), and safety within six months after intervention. DISCUSSION: This study investigates mainly from the patient perspective differences between meshes for treatment of incisional hernias. Whether partly absorbable meshes improve quality of life better than non-absorbable meshes is unclear and therefore, this trial will generate further evidence for a better treatment of patients. TRIAL REGISTRATION: NCT00646334.

Surgical management after neoadjuvant imatinib therapy in gastrointestinal stromal tumours (GISTs) with respect to imatinib resistance caused by secondary KIT mutations.

BACKGROUND: In metastasized GISTs, resistance to imatinib after initial tumour response has been associated with observation of secondary mutations in the activation loop of KIT. The aim of the current study was to evaluate the tumour response and observance of secondary KIT mutations in a case of GIST undergoing neoadjuvant imatinib therapy. METHODS: We report on a case of an initially unresectable gastric GIST with curative resection after 10 months of neoadjuvant imatinib therapy. Mutation analysis of KIT was performed on a pretherapeutic biopsy specimen, as well as on the resected tumour specimen. RESULTS: The pretherapeutic biopsy revealed cKit positive tumour cells with mutation of KIT exon 11 Del 560-576. The remaining tumour mass after neoadjuvant imatinib therapy almost exclusively consisted of hypocellular myxohyalinale stroma with rare microfoci of cKit positive tumour cells. Laser microdissection of several tumour microfoci revealed two additional point mutations located in the activation loop of KIT exon 17, C809G and N822Y, each observed separately in a distinct microfocus. Neither of these two point mutations has been reported in a GIST so far. CONCLUSIONS: Neoadjuvant imatinib therapy successfully reduces tumour size in GISTs. Since resistance relevant secondary mutations of the activation loop of KIT may be observed after neoadjuvant imatinib therapy, the time elapse with preoperative imatinib therapy should be chosen as short as curative tumour resection or function sparing surgery can be carried out. The determination of the optimal time point for surgery is therefore a critical event and will be discussed.

Differential diagnosis of gastrointestinal leiomyoma versus gastrointestinal stromal tumor.

INTRODUCTION: Strategies for the diagnosis of tumors arising in the intestinal muscular wall are rapidly evolving. Immunoreactivity for CD117 (KIT) usually supports the diagnosis of gastrointestinal stromal tumor (GIST), but a small subset of GISTs lacks KIT expression. In these cases the differential diagnosis of KIT-negative GIST versus one of their morphological mimics is difficult and bears critical implications for therapeutic management. CASE REPORT: Here, we report a case of a KIT-negative smooth muscle cell tumor of the colon in a 21-year-old man with the clinical appearance of GIST. Mutations of the KIT and platelet-derived growth factor receptor alpha (PDGFRA) gene could be ruled out. No chromosomal imbalances characteristic of GIST were found. However, cytogenetic analysis revealed losses at 7q, which has previously been reported in cases of uterine leiomyoma. DISCUSSION: We discuss current approaches to the differential diagnosis of true gastrointestinal smooth muscle cell tumor versus GIST.

Site-independent prognostic value of chromosome 9q loss in primary gastrointestinal stromal tumours.

Although the significance of tumour site for estimating malignant potential in gastrointestinal stromal tumours (GISTs) has recently been recognized, site-specific genetic patterns have not to date been defined. This study examined 52 c-kit-positive primary GISTs (with a mean follow-up of 42.3 months in 51 cases) from three different locations (35 gastric, 12 small intestinal, and five colorectal) using comparative genomic hybridization (CGH). In general, tumour site correlated with key prognostic factors, including tumour size, mitotic rate, proliferative activity, and probable malignant potential. Furthermore, several DNA copy number changes showed a site-dependent pattern. These included losses at 14q (gastric 83%, intestinal 35%; p = 0.001), losses at 22q (gastric 46%, intestinal 82%; p = 0.02), losses at 1p (gastric 23%, intestinal 88%; p = 1 x 10(-5)), losses at 15q (gastric 14%, intestinal 59%; p = 0.002), losses at 9q (gastric 14%, intestinal 53%; p = 0.006), and gains at 5p (gastric 11%, intestinal 53%; p = 0.002). These data demonstrate strong site-dependent genetic heterogeneity in GISTs that may form a basis for subclassification. Prognostic evaluation of DNA copy number changes identified losses at 9q as a site-independent prognostic marker associated with shorter disease-free survival (p = 0.03) and overall survival (p = 0.002). Furthermore, 9q loss also appeared to carry prognostic value in predicting overall survival for patients with advanced or progressive GISTs (p = 0.003).