Omental Tumor Research Articles

Metastatik Over Karsinomlarında Metastazla İlişkili NM23-H1, KAI1 ve MKK4 Genlerinin Ekspresyon Analizleri

Objective: Cytoreductive surgery as a basis of therapy in epithelial ovarian carcinomas (EOC) provides the primary tumor and metastatic tumor samples from a same patient. This gives an excellent opportunity for evaluation of metastatic factors by excluding inter-individual differences. Therefore, we aimed to define changes at mRNA levels of NM23-H1, KAI1 and MKK4 metastasis-related genes in the paired normal tissue, primary tumor and omental metastatic tumor samples obtained from a same patient. Material and Methods: mRNA levels were quantified by quantitative reverse transcription polymerase chain reaction (Q-RT-PCR) following total RNA extraction in normal tissues, primary malign tissues of EOC, and its metastatic lesions on omentum for 41 patients with stage III-C (FIGO) EOC. Results: We found that mRNA level of NM23-H1 was significantly higher in metastatic samples compared to primary tumors (p=0.009). On the other hand, MKK4 was found to be significantly lower in primary tumor samples compared to normal tissues (p=0.024). There was no significant change at mRNA level of KAI1 among normal tissues, primary tumors and omental metastatic tumor samples. Conclusion: We suppose that in detailed functional studies, approaches that suppress NM23-H1 gene and restore MKK4 gene would make these genes important molecular targets for treatment of metastatic EOC in the future.

Biomarker Expression in Pelvic High-grade Serous Carcinoma

Neoadjuvant therapy has an emerging role in the treatment of high-stage ovarian carcinoma. Some ovarian carcinoma subtypes do not respond well to standard chemotherapy, making accurate subtype diagnosis before starting therapy important. This diagnosis is frequently based on omental biopsy specimens. In particular, with very small biopsies, immunostaining for diagnostic biomarkers may be needed. To assess intratumoral heterogeneity of biomarker expression in pelvic high-grade serous carcinoma, we compared the expression of a set of 10 biomarkers between ovarian and omental sites. Tissue microarrays were constructed from 123 high-grade serous carcinomas with paired ovarian and omental tumor samples. These samples were stained with biomarkers that have been used in ovarian carcinoma subtype diagnosis (WT1, TP53/p53, MUC16/CA125, CDKN2A/p16), and with biomarkers of the tumor microenvironment (CD8, CD163, SPARC, PDGFRB), cell adhesion (CDH1/E-Cadherin), and proliferation (Ki67) as well. Expression frequencies in samples from the 2 sites were compared, as was concordance at the 2 sites for individual tumors. The 2 markers of desmoplastic stromal response (PDGFRB, SPARC) were more frequently expressed in the omentum compared with the ovary (P<0.001; McNemar test). The other 8 markers did not show a significant difference in the frequency of expression between sites. Within individual cases, some markers such as Ki67 and CDKN2A showed variability, indicating that these markers are affected by intratumoral heterogeneity. The intratumoral variability for MUC16, TP53, and WT1 was modest. Commonly used diagnostic markers, such as TP53 and WT1, show little variability between ovarian and omental sites, suggesting that they can be successfully used in small biopsy specimens from extraovarian sites. In contrast, markers of host stromal response do vary between sites, suggesting a biologic difference of the microenvironment at different sites that should be taken into account when tissue-based research is carried out.

Abstract LB-291: Central obesity drives oesophageal tumor cell growth through VEGF-mediated mechanisms

Abstract Introduction: Obesity is a risk-factor for both esophageal/colorectal adenocarcinoma. Adipose tissue is an endocrine organ secreting numerous factors, including Vascular Endothelial Growth Factor (VEGF). VEGF was identified to be up-regulated in cancer cells by affymetrix-array following co-culture with human omental adipose tissue (OAT). An understanding of the mechanisms driving obesity-related disease is needed to uncover pathways and develop new targets for therapy. In this study, we aimed to investigate the effect of OAT-derived VEGF on tumor growth and the potential of bevacizumab to block this effect. Methods: Matched subcutaneous and omental adipose tissue, serum and tumor were harvested from oesophageal/colorectal cancer patients undergoing resective surgery. VEGF was quantified in adipose conditioned media (ACM) and serum by ELISA. Proliferation of esophageal (OE33, JH-ESO) and colorectal (HCT15, SW480) cells following culture with ACM was assessed by BrdU assay. The protective effect of ACM on chemotherapy (cisplatin and 5FU) induced death was assessed. The effect of bevacizumab in attenuating these effects was also examined. VEGF and VEGF receptor 2 (KDR) expression was assessed in tumor tissue by qPCR. In a 200-patient tissue microarray, VEGF and VEGFR expression was related to clinico-pathological parameters and obesity status. Results: ACM from omental adipose tissue of obese patients significantly (p&amp;lt;0.05) increased proliferation in oesophageal (313%) and colorectal (424%) adenocarcinoma cell lines relative to omental adipose tissue from non-obese cancer patients (180% and 157% respectively). Interestingly, this effect was not observed in ACM from matched subcutaneous depots indicating that omental adipose tissue is more pro-tumor and metabolically active. Omental ACM from obese patients contained significantly higher levels of VEGF (p&amp;lt;0.05). In our patient cohort, serum VEGF was significantly elevated in centrally obese relative to normal weight cancer patients (determined by CT). There was a significant (p&amp;lt;0.05) higher expression of VEGF and KDR expression in esophageal tumours from centrally obese patients. The expression of KDR was higher in the leading edge of tumors from patients classified as obese, and was associated with decreased survival and increased nodal involvement. ACM from omental adipose tissue protected against 5FU-induced cell death (P&amp;lt;0.01), an effect which could be blocked by treatment with bevacizumab. Conclusion: VEGF from OAT increased proliferation in oesophageal/colorectal cancer cells. VEGF and KDR expression in oesophageal cancer was higher in centrally obese patients. ACM protected against chemotherapy-induced death, an effect that was mediated through VEGF. These findings suggest anti-VEGF strategies are warrented in obesity-associated malignancies, alone or in combination with conventional chemotherapies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-291. doi:10.1158/1538-7445.AM2011-LB-291

Omental vascular pedicle sign: Multidetector CT finding useful for diagnosis of an omental mass

To describe multidetector CT findings of "omental vascular pedicle" sign. "Omental vascular pedicle" sign was defined as dilated omental vein associated with a mass located in omentum and was observed in 7 patients (5 women, 2 men). Mean age was 45 years. CT examinations and patient records were retrospectively reviewed. CT images were obtained by 16-MDCT (n = 1) and 64-dual source MDCT (n = 6). Curved planar and volume rendered images were reconstructed from axial images. Diameter of omental vein and drainage site were recorded. Images were evaluated by 2 radiologists in consensus. Pathologic diagnosis of patients with "omental vascular pedicle sign" was omental angiosarcoma (n = 1), endometrial adenocarcinoma (n = 2), ovarian serous adenocarcinoma (n = 2), mixed gonadal tumor (n = 1), malignant peripheral sheath tumor (n = 1). In 5 patients, omental vein drained into splenic vein and in 2 patients it drained into right gastroepiploic vein. Mean size of omental masses associated with omental vascular pedicle was 7.1 × 4.5 cm (range 15 × 11 cm to 2.7 × 1.6 cm). Mean diameter of omental vein was 3.1mm (range 6-1.5mm). Diameter of the omental vein increased with the increasing size of omental masses and Pearson's correlation coefficient was 0.99. "Omental vascular pedicle sign" can be helpful to objectively diagnose omental masses in patients with primary and metastatic omental tumors.

Abstract 2331: One of the first steps of metastasis is remodeling of the extracellular matrix microenvironment

Abstract During metastasis tumor cells initiate processes that lead to the loss of normal tissue architecture and formation of the tumor microenvironment. The main site of metastasis in ovarian cancer (OvCa) is the omentum. Little is known about the initial changes in extra-cellular matrix (ECM) during early OvCa metastasis. A 3-dimensional (D) organotypic model of the omentum was used to investigate the remodeling of the ECMs during the initial steps of OvCa metastasis. Vitronectin and fibronectin increased when OvCa cells (SKOV3ip1 and Hey A8) were added to the 3D omental model, while collagen type I decreased. Vitronectin was produced by the cancer cells and stroma, while fibronectin was produced solely by cancer cells. Collagen type I decreases in stroma and increases in OvCa when co-cultured. Vitronectin, fibronectin and collagen type I are produced by primary human mesothelial cells and fibroblasts and are present in ascites. Two immunohistochemical studies with human tumors confirmed the above findings. First during early OvCa metastasis in humans, fibronectin is present in the stroma, while vitronectin and collagen type I are present in both cancer cells and the stroma. Second, ECM localization in 20 sets of primary and omental metastasis tumors from the same patients was performed. Fibronectin was absent in the primary tumor and present in the metastatic tumor stroma, while vitronectin was produced in cancer cells and stroma in primary and metastatic tumors. Additionally, a Reverse-Phase Protein Array was performed on primary versus omental metastasis tissue from 20 postmenopausal patients with FIGO Stage III/IV, high grade papillary-serous OvCa. Fibronectin was significantly increased, while vitronectin was significantly decreased in the omental metastasis vs. primary tumor, respectively. Additional experiments revealed changes in the tumor cell cytoskeleton in conjunction with increased expression of integrins (α5β1-and αvβ3-integrin) and proteases (uPA, uPAR, MMP-2 and MMP-9). Integrins and proteases were transiently knocked down using sequence-specific siRNA. Both α5β1-integrin and MMP-2, but not αvβ3-integrin and MMP-9, were found to be necessary for the remodeling of fibronectin. Taken together, these findings reveal the initial transformation of ECM in the normal omental architecture during early OvCa metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2331.

Metastatic Omental Tumor Secondary to Occult Ovarian Serous Adenocarcinoma

Primary tumors within the abdomen frequently spread to the mesentery and omentum, but these deposits may not cause symptoms until they grow large enough to displace organs or cause intestinal obstruction. We present an uncommon case of occult ovarian serous adenocarcinoma presenting as a solitary metastatic omental mass. A 72-year-old female patient found a hard, mobile subcutaneous mass located at the umbilical area. This mass gradually became larger, but there were no symptoms in the gastrointestinal tract. Abdominal ultrasonography showed a homogenous, hypoechoic lesion. A preoperative diagnosis of a huge intra-abdominal lipoma was made, and surgical intervention was carried out. Intraoperatively, we found a tumor mass located in the greater omentum without ascites. The surgical procedure consisted of a complete resection of the omental mass. Frozen section analysis by the pathologist revealed a metastatic serous adenocarcinoma. Intra-abdominal organs including the gastrointestinal tract, ovaries, uterus and pancreas were examined carefully; however, no abnormal lesions were identified either grossly or palpably. Two months after the operation, a computed tomographic scan of the abdomen was performed, and a cystic mass lesion with a 0.9-cm lobulated margin was confirmed in the posterior wall of the right ovary. The patient was then referred to a gynecologist for further survey and underwent another operation. Finally, a pathologic report of the right ovary showed that the primary lesion of this metastatic omental cancer originated from right ovarian cancer. This case demonstrates the possibility of development of a metastatic omental mass from an occult ovarian serous adenocarcinoma.

Primary Omental Myxoid Leiomyosarcoma: Report of a Case and a Review of the Literature

A 41-year-old Japanese woman who presented with right lower abdominal pain underwent partial omental resection with tumor excision, leaving no residual tumor. The tumor was diagnosed as a myxoid leiomyosarcoma that apparently originated in the greater omentum. A recurrent omental tumor was excised at 4.5 months after the first operation, and then at 5.5 months after this, CT revealed metastatic sarcoma at the surface of the liver (S7) and the left upper abdomen. She died 20 months after the last operation despite treatment of the metastases with MAID therapy (mesna, adriamycin, ifosfamide, dacarbazine). A literature review revealed that this tumor mainly occurs in the uterus, soft tissue, and cardiovascular system, with a preponderance among middle-aged to elderly women. The present report is the first description of primary omental myxoid leiomyosarcoma. ACTA MEDICA NAGASAKIENSIA 54: 21－24, 2009

Administration of Glucocorticoids to Ovarian Cancer Patients Is Associated with Expression of the Anti-apoptotic Genes SGK1 and MKP1/DUSP1 in Ovarian Tissues

To prevent chemotherapy-related side effects, synthetic glucocorticoids, for example, dexamethasone, are routinely administered to patients with ovarian cancer. However, preclinical data implicate glucocorticoids in suppressing chemotherapy-mediated apoptosis in epithelial tumors. The anti-apoptotic mechanisms underlying this increased survival have been shown to require up-regulation of prosurvival genes, including serum and glucocorticoid-regulated kinase 1 (SGK1) and map kinase phosphatase 1 (MKP1)/dual specificity phosphatase 1 (DUSP1). Despite abundant preclinical data, there are no correlative studies in patients. We therefore evaluated anti-apoptotic gene expression in tumor samples from patients randomized to dexamethasone or normal saline. Eighteen patients were randomized before exploratory laparotomy for suspected ovarian cancer. Dexamethasone or normal saline was administered i.v. following anesthesia. Ovarian and omental tumor samples were collected intra-operatively before and after infusion. Samples were analyzed for histology and glucocorticoid receptor expression by immunohistochemistry. SGK1 and MKP1/DUSP1 mRNA levels were determined using quantitative real-time PCR. Ten patients were evaluable. At 30 min postinfusion, tumor samples from five patients receiving dexamethasone revealed an average SGK1 mRNA induction of 6.1-fold (SEM, +/-2.6) compared with only 1.5-fold (SEM, +/-0.4) in tumor samples from five patients receiving normal saline (P = 0.028). Average MKP1/DUSP1 mRNA expression was increased by 8.2-fold (SEM, +/-2.9) following dexamethasone versus 1.1-fold (SEM, +/-0.4) following normal saline (P = 0.009). All samples expressed glucocorticoid receptor. Glucocorticoid administration to patients is associated with rapid up-regulation of SGK1 and MKP1 expression in ovarian tumors. This finding supports the hypothesis that pharmacologic doses of glucocorticoids may decrease chemotherapy effectiveness in ovarian cancer patients through increased anti-apoptotic gene expression.

Omental immune aggregates and tumor metastasis within the peritoneal cavity

The omentum, an important peritoneal tissue, is studded with a high number of immune aggregates, or "milky spots," the number, function, and phenotype of which is largely unknown. We have analyzed the immune composition on the normal omentum and also have shown that both free immune cells and tumor cells in the peritoneal fluid bind preferentially to these immune aggregates. This binding may be mediated by the network of collagen I fibers, which overlay these areas. In addition, we have shown that not only do omental vessels express vascular endothelial growth factor receptor 3 (VEGFR3), a receptor that is only found on angiogenic blood vessels, but that tumor cells co-localize with these vessels, possibly increasing the ability of tumor to induce neovascularization and therefore thrive.

Fibroma of the Omentum Resembling an Ovarian Tumor in the Pelvis

We would like to report the case of a patient with fibroma of the omentum that resembled an ovarian tumor in the pelvis. Since primary tumours of the omentum are rare, there is a paucity of information about the biology of such tumors in the basic texts and literature. An ultrasound examination of the patient revealed a mass, likely of ovarian origin, which consisted of liquid and solid components. It was suspected to be a malignant ovarian tumor. However, laparotomy demonstrated it was an omental tumor. This case shows that it can be difficult to pre-operatively diagnose omental fibromas because of their close resemblance to ovarian tumors.

Tumor-Penetrating Microparticles for Intraperitoneal Therapy of Ovarian Cancer

Intraperitoneal chemotherapy prolongs survival of ovarian cancer patients, but its utility is limited by treatment-related complications and inadequate drug penetration in larger tumors. Previous intraperitoneal therapy used the paclitaxel/Cremophor EL (polyethoxylated castor oil) formulation designed for intravenous use. The present report describes the development of paclitaxel-loaded microparticles designed for intraperitoneal treatment (referred to as tumor-penetrating microparticles or TPM). Evaluation of TPM was performed using intraperitoneal metastatic, human ovarian SKOV3 xenograft tumor models in mice. TPM were retained in the peritoneal cavity and adhered to tumor surface. TPM consisted of two biocompatible and biodegradable polymeric components with different drug release rates; one component released the drug load rapidly to induce tumor priming, whereas the second component provided sustained drug release. Tumor priming, by expanding interstitial space, promoted transport and penetration of particulates in tumors. These combined features resulted in the following advantages over paclitaxel/Cremophor EL: greater tumor targeting (16-times higher and more sustained concentration in omental tumors), lower toxicity to intestinal crypts and less body weight loss, greater therapeutic efficacy (longer survival and higher cure rate), and greater convenience (less frequent dosing). TPM may overcome the toxicities and compliance-related problems that have limited the utility of intraperitoneal therapy.

Intussusception caused by metastatic cervical cancer

Intussusception inadultsisuncommon.Itisprimarily observed in children, with 95% of cases occurring before the age of 17 years. In contrast to children, where intussusceptions presentwiththe classictriad of abdominalpain, vomiting, and currant-jelly stools, adultspresent with nonspecific symptoms such as abdominal pain, nausea, vomiting, and constipation (1,2). The majority of adult intussusceptions are secondary to tumor and require surgery for reduction and/or resection. A predisposing pathologic cause or lead point is found in up to 90%of adultintussusceptions, whereasmostchildintussuscep- tions are idiopathic (3). A 34-year-old woman presented with abdominal bloating 14 months after radical hysterectomy and lymph node dissection for FIGO stage IB1 cervical adenocarcinoma with negative lymph nodes. A computed tomography (CT) scan revealed an omental tumor and ascites. The patient under- went 6 cycles of chemotherapy with a complete clinical response. Seven months later the patient was admitted with nausea and poor oral intake. An abdominal X-ray suggested a small bowel obstruction and a CT scan revealed multiple hepatic lesions, confirmed by biopsy as recurrence. The patient was discharged after 9 days of conservative manage- ment and chemotherapy was reinitiated. The patient presented 2 months later with nausea, vomiting, and abdominal distension despite normal bowel

Glomus tumor of the omentum: A case report

Computed tomography revealed a well-enhanced omental mass. Magnetic resonance imaging demonstrated a mass with low signal intensity on T1-weighted images (WI) and high signal intensity on T2-WI. Resected specimens immunohistochemically showed positive results for alpha-smooth muscle actin, muscle-specific actin (HHF35) and vimentin, and negative results for S-100 protein, CD34, desmin, EMA, keratin, calretinin, HBME1, and c-kit. This is the first case of an omental glomus tumor reported in the English literature.

Primary omental Gastrointestinal stromal tumor (GIST)

BackgroundWe report herein a rare case of primary omental gastrointestinal stromal tumor (GIST).Case presentationA 65 year-old man was referred to our hospital with a huge abdominal mass occupying the entire left upper abdomen as shown by sonography. On computed tomography (CT), this appeared as a heterogeneous low-density mass with faint enhancement. Abdominal angiography revealed that the right gastroepiploic artery supplied the tumor. With such an indication of gastric GIST, liposarcoma, leiomyosarcoma or mesothelioma laparotomy was performed and revealed that this large mass measured 20 × 17 × 6 cm, arising from the greater omentum. It was completely resected. Histopathologically, it was composed of proliferating spindle and epithelioid cells with an interlacing bundle pattern. Immunohistochemically, the tumor was positive for myeloid stem cell antigen (CD34), weakly positive for c-KIT (CD117) and slightly positive for neuron-specific enolase (NSE), but negative for cytokeratin (CK), alpha-smooth muscle actin (SMA) and S-100 protein. A mutation was identified in the platelet-derived growth factor alpha (PDGFRA) juxtamembrane domain (exon 12, codon561) and the tumor was diagnosed as an omental GIST. The postoperative course was uneventful. The patient is treated by Glevec® and is alive well with no sign of relapse.ConclusionOur case demonstrated a weak immunohistochemical expression of c-kit (CD117) and a point mutation in PDGFRA exon 12 resulting in an Asp for Val561 substitution. Imatinib therapy as an adjuvant to complete resection has been carried out safely. Because of the rarity of primary omental GISTs, it is inevitable to analyze accumulating data from case reports for a better and more detailed understanding of primary omental GISTs.

Omental Chemotherapy Effects as a Prognostic Factor in Ovarian Cancer Patients Treated With Neoadjuvant Chemotherapy and Delayed Primary Surgical Debulking

We sought to assess the prognostic significance of chemotherapy effect on upper abdominal metastatic disease. Retrospective chart reviews were carried out from 1997 to 2005 to identify ovarian cancer patients treated with neoadjuvant chemotherapy. Pathologic examinations of resected omental and ovarian tumors for the presence of chemotherapy effect were performed. Cox proportional hazard models were built to model time to progression and death by using predictor variables of age, tumor grade, amount and location of largest residual disease, and the presence of chemotherapy effects on resected tumors. Sixty-six patients with available slides and clinical information were identified. The presence of omental chemotherapy effects was observed in 58 patients (88%). Identified independent statistically significant predictors for progression-free survival included presence of omental chemotherapy effect (hazard ratio [HR], .38; 95% confidence interval [95% CI], .17-.89; P = .026) and suboptimal tumor residuals in upper abdominal location compared with pelvic location (HR, 2.41; 95% CI, 1.06-5.48; P = .035). The presence of omental chemotherapy effect was the only statistically significant predictor of disease specific survival (HR, .21; 95% CI, .068-.639; P = .006). The estimated median survival for the group with positive omental chemotherapy effect was 84.45 months (95% CI, 69.63-99.28). The corresponding statistic in patients with no observed response to chemotherapy was 31.15 months (95% CI, 21.84-40.47). Upper abdominal disease location and its response to chemotherapy were independent prognostic factors for progression-free survival. Aggressive upper abdominal debulking procedures are recommended to improve oncologic outcomes.

Pseudotumor of the omentum with a fishbone nucleus

A 23-year-old Japanese man was admitted with a chief complaint of abdominal pain. He was previously healthy, and his past medical history was unremarkable. Local tenderness and rebound tenderness at McBurney's point were elicited. Abdominal roentgenography was non-diagnostic. Ultrasonography and computed tomography showed a tumor with a central core. Based on a diagnosis of appendicitis with omental inflammation or an omental tumor, laparotomy performed. Intraoperatively, no site of gastrointestinal perforation was detected; however, a 5-cm omental granuloma was identified that proved to have a fishbone nucleus on pathological examination. The postoperative course was uneventful, and upper gastrointestinal endoscopy and barium enema were unremarkable. A large solitary omental pseudotumor is rare, and the clinical course in this case was atypical compared with the usual course of intestinal perforation by a foreign body and formation of an intra-abdominal granuloma.

Clinicopathologic study of 275 cases of gastrointestinal stromal tumors: the experience at 3 large medical centers in Mexico

It is important to distinguish gastrointestinal (GI) stromal tumors (GISTs) from other GI mesenchymal tumors (GIMTs) because of the availability of molecular-targeted therapy for GISTs. The aim of the study was to reclassify GIMTs and to determine the clinicopathologic features of GISTs in Mexico. Cases of GIMT identified from the database of 3 large diagnostic centers in Mexico between 1995 and 2004 were reclassified according to current criteria. Hematoxylin and eosin-stained sections and clinical histories were reviewed, and immunohistochemistry was performed using anti-CD117, CD34, smooth muscle actin, and S-100 protein. A total of 275 GISTs were identified. The tumors were located in the stomach (40%), small intestine (35%), colorectum (12%), abdominal cavity (11%), and esophagus (2%). There were equal numbers of men and women with a mean age at diagnosis of 61 years. The tumors ranged in size from 3.5 to 34 cm (mean, 9.1 cm); 95 tumors (34%) were larger than 10 cm. Colorectal and omental tumors were the largest. The cell types included pure spindle (68%), pure epithelioid (16%), and mixed epithelioid/spindle (14%). Whereas 17.8% of tumors were regarded as low risk, 43% of tumors were in the high-risk category. CD117 positivity was detected in most of the tumors (96%). In addition to CD117, 255 cases (92%) were positive for CD34, 82 cases (32%) were positive for smooth muscle actin, and 13 cases (4.7%) were positive for desmin. Gastrointestinal stromal tumors in Mexico have the same clinicopathologic and immunohistochemical features as those reported in other countries. It is not always easy to distinguish GISTs from other soft tissue lesions. The diagnosis can be difficult even for experienced pathologists.

Accumulation of Tc-99m MDP by Omental Tumor in Metastatic Cecal Cancer

Soft tissue metastases from epithelial tumors often accumulate radiopharmaceutical at methylene diphosphonate (MDP) scintigraphy. Although this is most commonly seen in the liver, peritoneal disease can sometimes be appreciated. Malignant ascites may demonstrate either a diffuse intraabdominal accumulation of radiopharmaceutical or U-shaped flank activity with relative central photopenia as a result of mesentery and bowel loops. We present a case of extensive omental tumor in a patient with metastatic cecal cancer incidentally discovered at bone scintigraphy. Soft tissue activity in both flanks and lower abdomen was initially attributed to uptake in ascites, but solid tumor was identified at subsequent CT scanning.

Endodermal Sinus Tumor of the Omentum: Case Report

We report a case of primary endodermal sinus tumor of the omentum in a 46-year-old woman. The patient had been referred to our hospital for pain in the right abdomen. CT scan revealed a right-sided abdominal mass. At laparotomy, a large omental tumor extending to the bowel, uterus, ovaries and peritoneum was found, and it was totally resected. The tumor displayed the typical histological patterns observed in endodermal sinus tumor, and the immunohistochemical findings confirmed the diagnosis. Serum AFP level was 21.550 ng/ml prior to laparotomy, and decreased to 13.845 ng/mL after surgery, whereas the level of serum beta human chorionic gonadotropin was normal. Post-surgery, the patient received combination chemotherapy consisting of cisplatin, etoposide and bleomycin every 3 weeks for a total of 6 cycles. At the end of the treatment, all the findings, including AFP level, were normal.

Pneumoperitoneum does not influence trocar site implantation during tumor manipulation in a solid tumor model

The purpose of this study was to assess tumor implantation at abdominal wound sites following manipulation of a solid abdominal tumor. GW-39 human colon cancer cells were injected into the omentum of golden Syrian hamsters. At 2 weeks, an omental tumor was harvested and animals were randomized to bivalve (A), crush (B), strip (C), or excision (D), with or without pneumoperitoneum. Four 5-mm trocars were inserted into the abdomen, and the tumor was reinserted through the midline, swept through four quadrants, and removed. The incision was closed and pneumoperitoneum at 7 mmHg was maintained for 10 min. Tumor implantation at wound sites was documented at 7 weeks. Implantation at trocar sites was 53 and 49% with and without pneumoperitoneum in the manipulated groups (A, B, C), respectively (p = 0.993). Implantation at trocar sites was reduced in the control group (D) at 9 and 10% with and without pneumoperitoneum, respectively (p < 0.001). Tumor implantation at trocar sites is due to spillage of tumor during manipulation and not to pneumoperitoneum.