Omental Lesions Research Articles

Diagnostic value of multidetector computed tomography in differentiation of benign and malignant omental lesions

ObjectiveTo assess the diagnostic value of multidetector computed tomography (MDCT) in differentiation of benign and malignant omental lesions. Patients and methodsMDCT scan was performed for 37 patients with omental lesions after administration of oral and intravenous contrast. The CT diagnosis was compared with the final histopathological findings. Sensitivity, specificity, and diagnostic accuracy of MDCT were calculated using surgical and histopathological findings as the gold standard. ResultsMDCT findings of all cases with omental torsion, cystic lymphangioma, and loculated fluid in the greater omentum correlated with the surgical and histopathological findings with 100% diagnostic accuracy. However, the diagnosis was missed in two patients from seven (2/7) with tuberculous peritonitis and in two patients from 21 (2/21) with peritoneal carcinomatosis with sensitivity, specificity and diagnostic accuracy of 73%, 92%, 85% and 90%, 95%, 93%, respectively. ConclusionMDCT is an excellent diagnostic tool for evaluating omental lesions, especially those present with nonspecific clinical manifestations.

P10.02 * UTERINE CARCINOSARCOMA WITH PARANEOPLASTIC CEREBELLAR DEGENERATION: CASE ANALYSIS WITH LITERATURE REVIEW

INTRODUCTION: Paraneoplastic neurologic syndromes (PNS), a heterogeneous group of oncologic immune-mediated neurologic disorders, often antedate cancer diagnosis. PNS recognition results in early cancer screening/treatment. Paraneoplastic cerebellar degeneration (PCD) is an aggressive/debilitating/fatal PNS characterized by pancerebellar symptoms – progressive ataxia/dysarthria/nystagmus/vertigo. PCD is predominantly associated with breast/gynecologic cancers. Though 12 onconeural antibodies are implicated in PCD, anti-Yo antibody is the most common/specific antibody seen in PCD. We present the first case of anti-Yo PCD associated with uterine carcinosarcoma. METHOD: Case analysis. CASE: 78yo female presented with month-long history of ataxia/gait instability/falls and abrupt onset diplopia/nausea/vomiting without fever/syncope/headache /dysarthria. Past medical history was significant for right breast T1 N0 invasive ductal carcinoma s/p partial mastectomy and adjuvant whole breast radiation that occurred 1 year prior to presentation. Neurologic exam revealed intact language/comprehension, left sixth cranial nerve palsy, truncal/limb ataxia, bilateral horizontal nystagmus, and symmetric 3+ deep tendon reflexes without focal deficits or dystonia noted. Routine blood work was unremarkable. Brain MRI with/without contrast noted no evidence of metastatic disease/demyelinating process/hemorrhage/infarction. She declined CSF studies. Within two months, she developed dysarthria/dysphagia and was unable to stand without assistance due to progressive ataxia. PNS laboratory evaluation yielded high titer of anti-Yo antibody (1/245,760) with positive Western blot assay as the only onconeural antibody. Chest/abdomen/pelvis CT scan demonstrated multiple soft tissue lesions in the omentum with bilateral sub-centimeter pulmonary nodules. Tumor marker analysis noted elevated CA-125/CA-27.29/CA-15.3. CT guided biopsy of omental lesions revealed poorly differentiated carcinosarcoma. Immunohistochemistry confirmed malignant stage IV uterine carcinosarcoma. Chemotherapy with IVIG was initiated. Though tumor burden size decreased, PCD progressed (bedbound, increased anti-Yo antibody titers). Rapid neurologic decline required hospice 8 months after PCD diagnosis associated with uterine carcinosarcoma. She died 1 month later. CONCLUSIONS: This case confirms anti-Yo PCD association with uterine carcinosarcoma. PCD requires early cancer screening/treatment and aggressive multi-modal immunotherapy interventions. Clinicians should have a low threshold for PCD. Double primary cancers must be considered. Prospective trials addressing anti-Yo PCD therapeutic interventions, illness progression, associated cancer, double primary, and survival are indicated. Clinicians require further education regarding PCD and other PNS.

18F-FDG PET Imaging in a Patient With Late Omental Infarction After Treatment of Pancreatic Adenocarcinoma

We report a case of late omental infarction visualized by F-FDG PET/CT during follow-up for pancreatic adenocarcinoma. The 65-year-old patient was referred for imaging 8 months after pancreaticoduodenectomy and 2 months after completion of a course of chemotherapy. PET/CT showed an FDG-avid omental lesion that suggested peritoneal carcinomatosis. The appearance and evolution at follow-up studies confirmed the diagnosis of omental infarction, a rare complication of pancreatic surgery. This case revealed the possibility of late FDG uptake in omental infarction.

Identification of Ovarian Cancer Metastatic miRNAs

Serous epithelial ovarian cancer (EOC) patients often succumb to aggressive metastatic disease, yet little is known about the behavior and genetics of ovarian cancer metastasis. Here, we aim to understand how omental metastases differ from primary tumors and how these differences may influence chemotherapy. We analyzed the miRNA expression profiles of primary EOC tumors and their respective omental metastases from 9 patients using miRNA Taqman qPCR arrays. We find 17 miRNAs with differential expression in omental lesions compared to primary tumors. miR-21, miR-150, and miR-146a have low expression in most primary tumors with significantly increased expression in omental lesions, with concomitant decreased expression of predicted mRNA targets based on mRNA expression. We find that miR-150 and miR-146a mediate spheroid size. Both miR-146a and miR-150 increase the number of residual surviving cells by 2–4 fold when challenged with lethal cisplatin concentrations. These observations suggest that at least two of the miRNAs, miR-146a and miR-150, up-regulated in omental lesions, stimulate survival and increase drug tolerance. Our observations suggest that cancer cells in omental tumors express key miRNAs differently than primary tumors, and that at least some of these microRNAs may be critical regulators of the emergence of drug resistant disease.

Abstract 5323: Fractalkine receptor CX3CR1 regulates peritoneal dissemination of ovarian carcinoma

Abstract Epithelial ovarian carcinoma (EOC) is the deadliest gynecologic malignancy largely due to the metastatic disease. EOC metastases spread by shedding the malignant cells off of the ovarian surface and seeding tissues and organs of the peritoneal cavity. Currently used therapies, a combination of chemotherapy and surgery, fail to keep most patients in the remission. Mechanistic understanding of the biology of EOC metastasis will facilitate development of new therapeutic approaches. Our previous data demonstrated that fractalkine receptor (CX3CR1) is expressed by EOC cells and can support cell migration and proliferation. Moreover, our previous data suggested that CX3CR1-positive EOC cells can adhere to the CX3CL1-postive peritoneal mesothelial cells in in vitro assay. Thus, we hypothesized that CX3CL1/CX3CR1 axis could be important for peritoneal dissemination of metastatic EOC. To test this hypothesis, we performed short-term ex vivo and in vivo adhesion assay, as well as long-term metastasis formation assay. Expression of CX3CR1 in EOC cells was downregulated in SKOV-3 using shRNA. Both CX3CR1 shRNA-expressing and scrambled shRNA-expressing EOC cells were seeded atop of mouse peritoneum and omentum tissues in the ex vivo assay and allowed to adhere for up to 24 h. CX3CR1 shRNA-expressing and scrambled shRNA-expressing EOC cells were intraperitoneally injected into abdomens of athymic nude mice for 4 h following sacrifice of the animals and examination of the peritoneal organs and tissues for green fluorescence. Data analysis has demonstrated that downregulation of CX3CR1 in EOC cells led to a significant decrease of adhesion in these assays. Furthermore, parental SKOV-3 as well as CX3CR1 shRNA-, scrambled shRNA-, and vector shRNA-expressing cells were intraperitoneally injected into athymic nude mice and allowed to form metastasis for 10 weeks. As a result, we observed very small omental metastatic lesions in three out of six animals injected with CX3CR1 shRNA-expressing cells. In opposite, all of the control groups developed gross intraperitoneal metastasis in many organs and tissues. Our data suggest that CX3CR1 may be one of the key factors that determine peritoneal dissemination of EOC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5323. doi:1538-7445.AM2012-5323

Value of diffusion-weighted imaging for assessing site-specific response of advanced ovarian cancer to neoadjuvant chemotherapy: Correlation of apparent diffusion coefficients with epithelial and stromal densities on histology

This study correlates apparent diffusion coefficients (ADCs) from Diffusion-weighted Imaging (DWI) in primary ovarian tumours and their omental metastases following neoadjuvant chemotherapy with epithelial and stromal densities in order to relate them to histological composition. Eight patients underwent DWI at 1.5 T with four b-values (0, 600, 900, and 1,050 s/mm(2))at baseline and after one and three cycles of platinum-based chemotherapy. Mean ADCs were calculated at each timepoint from solid tumour at ovarian and omental sites. Specimens from 15 corresponding lesions (8 ovarian, 7 omental), obtained at interval debulking surgery, were stained immunohistochemically to quantify epithelial and stromal components. End-of-treatment ADC was correlated with epithelial and stromal densities. Longitudinal changes in ADC with treatment were compared between primary and metastatic lesions using parametric tests. No baseline differences in ADC between primary and metastatic sites were seen. Mean ADC increased significantly from baseline after both first and third cycle (P < 0.001) in both ovarian and omental lesions. ADC and total epithelial plus stromal density (lesion cellularity) were negatively correlated in ovarian lesions (r= -0.79, P=0.02) but not in omental metastases or when both sites were considered together. However, ADC and epithelial density were negatively correlated in ovarian (r=- 0.78, P=0.02) and omental lesions (r=-0.75, P=0.04) and when both sites were considered together (r=-0.77, P< 0.001). There was no significant correlation between ADC and stromal density. Thus ADC reflects mainly epithelial content in advanced ovarian cancer and is not solely a function of lesion cellularity.

Non-islet cell tumour hypoglycaemia due to clear cell hepatocellular carcinoma

Background Hepatocellular carcinoma (HCC) is a common primary liver cancer worldwide with increasing incidence in Australia. 1 Methods and Results We report a case of a 72-year-old female who presented with profound, treatment-refractory hypoglycaemia and on subsequent investigation a liver mass and omental metastasis was found. Hormonal analysis was consistent with non-islet cell tumour hypoglycaemia (NICTH) mediated by insulin-like growth factor-II (IGF-II). Biopsy of the omental lesion showed extensive necrosis and areas of sclerotic stroma infiltrated by cohesive groups of neoplastic clear cells. An immunohistochemical (IHC) panel demonstrated staining of tumour cells with HepPar1, alpha fetoprotein, cytokeratins and canalicular staining for pCEA suggestive of HCC. The patient succumbed despite aggressive management. A post-mortem examination demonstrated a non-cirrhotic liver with a 23 cm mass in the left lobe, multiple intrahepatic metastases, and a 13 cm omental metastasis with histological and IHC features consistent with a primary clear cell HCC. Discussion NICTH resulting from tumour mediated overproduction of precursor IGF-II is an uncommon complication of malignancy. 2 It has only been rarely reported with clear cell HCC of the liver. 3 Moreover, clear cell HCC is infrequently described 4,5 and is rare in non-cirrhotic liver disease. 5,6

Color Doppler Ultrasonographic Flow Parameters in the Differentiation of Benign and Malignant Causes of Omental Thickening

The purpose of the study was to determine if color Doppler ultrasonographic (US) quantitative flow parameters are valuable to differentiate malignant peritoneal or omental involvement from benign causes. Twenty-six consecutive patients with peritoneal or omental thickening detected by gray scale US, computed tomography, and magnetic resonance underwent color Doppler US examinations. All the Doppler signal waveforms were recorded, and resistive (RI) and pulsatility indices (PI) were calculated automatically by the US machine. In the statistical analysis of RI and PI, unpaired t test was used. A P < 0.05 was considered significant. Nineteen of 20 malignant and 5 of 6 benign lesions had detectable color Doppler US pulsatile flow signals. The mean RI and PI values were 0.6260 and 1.36, respectively, for the benign group and 0.5384 and 1.4147, respectively, for the malignant group. For malignant lesions, mean RI was lower (P = 0.0796), and mean PI was higher (P = 0.9183) than benign lesions. However, these differences were not statistically significant. Overlapping RI and PI values in benign and malignant omental lesions limit the clinical value of flow parameters in the differentiation of benign and malignant involvement of the omentum.

Volcano Ulcers in Stomach – an Unusual Presentation of Metastatic Non Pigmented Melanoma

Purpose: Malignant melanoma is one of the most common malignancies to metastasize to the gastrointestinal (GI) tract. Metastases to GI tract can present at time of primary diagnosis or decades later as first sign of recurrence. Metastatic melanoma to GI tract is found during diagnostic workup in 1%-4% of patients with cutaneous primary and up to 60% of melanoma patients in autopsy. Methods: Our patient is a 45 year old white male with history of primary non-pigmented urinary bladder melanoma who presented with complaint of dyspepsia for 2 months. Patient had received full course of chemotherapy with Tamodar for 5 months with good response. He denied any nausea, vomiting, dysphagia or bleeding. He had no primary skin lesion found on extensive detailed physical exam. Whole body PET scan showed markedly thickened stomach walls with multiple omental lesions in the perigastric region. Upper endoscopy revealed two large, non-pigmented ulcerating masses in body of stomach on the greater curvature. These masses had “volcano appearance” with heaped up edges and central crater. Multiple biopsies were taken which were consistent with non pigmented metastatic melanoma confirmed by immunohistochemical stains. Patient was subsequently started on carboplatin and has had mild improvement in symptoms. Results: Conclusion: Gastrointestinal invasion by melanoma is a rare condition and is often associated with invasion of other visceral organs. The endoscopic classification of the gastric metastases comprises three main types: (a) melanotic nodules, often ulcerated at the tip; most common (b) submucosal mass, melanotic or not, elevated and ulcerated at apex; typical aspect of “bull's eye” lesion and (c) mass lesions with varying incidence of necrosis and melanosis. Gastric metastases may appear even as a simple ulcer. Majority of gastric metastases are reported to occur in body and fundus, most often on the greater curvature. Most frequent sites of melanoma metastases include small bowel, stomach, colon, and anorectum in decreasing order. Symptoms may include abdominal pain, dysphagia, small bowel obstruction and GI bleed. Diagnosis requires careful inspection of mucosa and biopsy with special immunohistochemical stains. Management may include surgical resection, chemotherapy, immunotherapy, observation, or enrollment in clinical trials. Surgery seems to be of limited value and should be performed in carefully selected patients and in patients with complications. Prognosis is poor, with median survival time in patients presenting with GI invasion being less than 1 year. Endoscopic “Volcano ulcers” in the stomach have been reported in many secondary neoplasms of the stomach and their presence should always raise suspicion for an underlying malignancy.

Treatment of an Advanced Ovarian Cancer Patient Receiving Hemodialysis

Treatment of patients with advanced ovarian cancer mainly involves aggressive cytoreductive surgery and administering adjuvant chemotherapy with carboplatin and paclitaxel. Carboplatin is metabolized by the kidney, and thus, a diminished dose of carboplatin is considered for patients with chronic renal failure to prevent further renal impairment resulting in secondary complications, such as anemia, hypertension, and thrombocytopenia [1,2]. Paclitaxel is metabolized by the liver, and less than 10% of the metabolite is eliminated renally [3]. So, we are able to administer a full dose of paclitaxel in renal insufficient patients, since its elimination does not depend on renal clearance [2]. Here, we present the course of treatment of a patient with advanced ovarian cancer who was receiving hemodialysis. A woman aged 69, gravida 2, para 2, had suffered from glaucoma for 12 years and chronic nephritis for 10 years and was receiving hemodialysis three times a week. The patient attended hospital because of the lower abdominal pain she had suffered for 4 months. Pelvic ultrasonography revealed a right adnexal tumor 12 × 10 × 9 cm in size and a left adnexal tumor 5.4 × 3.2 × 3 cm in size, which were partly solid and had an irregular septum. Multiple enlarged right axillary lymph nodes were also found. In addition to the aforementioned findings, pelvic computed tomography scan revealed an omental lesion. Laboratory findings were as follows: 1,603 U/mL CA125, 95 mg/dL blood urea nitrogen (BUN), and 7.7 mg/mL creatinine. Transperitoneal laparotomy confirmed that the bilateral ovarian tumor had invaded the bilateral fallopian tubes and the surface of the uterus and had metastasized to the greater omentum and peritoneum. The patient underwent total hysterectomy, bilateral salpingo-oophorectomy, omentectomy, pelvic lymphadenectomy, and right axillary lymphadenectomy. Pathologic findings indicated undifferentiated papillary serous adenocarcinoma. Pelvic lymph nodes were unaffected, but right axillary lymph nodes were affected by serous adenocarcinoma. The patient was diagnosed with stage IV ovarian cancer, according to the International Federation of Gynecology and Obstetrics (FIGO) staging system. After surgery, the patient was treated with carbo

The correlation of the AKT/mTOR/p70S6K1 pathway and VEGF in human epithelial ovarian cancer

16081 Background: The Akt/mTOR/p70S6K1 (Amp) pathway is activated in a proportion of epithelial ovarian cancers. The ribosomal protein pS6 and p4EBP1 are downstream targets and presumed representative for the pathway's activity. VEGF and angiogenesis in ovarian cancer play an important role as bevacizumab induces high response rates and prolongs progression-free survival in women with relapsed ovarian cancer in two phase II trials. The Amp pathway has proven to be correlated with HIF1alfa and VEGF A expression in vitro. Material and Methods: Our primary objective was to evaluate correlation between this pathway in human subject tissues and angiogenesis using VEGF A and pVEGFR2. Our second objective was to evaluate if different metastatic abdominal (peritoneal and/or omental) lesions show the same pathway hyperactivity and/or angiogenesis as the primary tumour, because relapses usually involve metastatic abdominal lesions. Epithelial ovarian cancer paraffin imbedded material from 1999–2004 was collected. A tissue micro array was build with three samples per paraffin block. Immunohistochemical staining was performed using pS6, p4EBP1, pAKT, VEGF and pVEGFR2. Results: 89 patients were collected with a median age of 69.8y. Patients were FIGO stage I in 21%, stage II in 4%, stage III in 62% and 11% stage IV. Histological examination showed in 53% serous papillary tumours, 25.8% endometroid tumours, clear cell carcinoma in 11.2% and mucinous tumours in 4.5%. 65 patients had available tissue material of both primary tumour as well as other (multiple) metastatic abdominal disease tissue. The results of the immunohistochemical staining as well as the correlation analysis will be presented. Conclusion: Although anti-angiogenesis seems to be very active against human epithelial ovarian cancer, it is at present associated with unacceptable treatment induced toxicities. Inhibiting the Amp pathway with mTOR inhibitors could potentially also inhibit angiogenesis in ovarian cancer with the potential of more manageable side effects. This study will provide some evidence on the relationship between the Amp pathway and the VEGF pathway in human epithelial ovarian cancer. No significant financial relationships to disclose.

An Unusual Case of Metastatic Gastric Adenocarcinoma in a 19-yr-Old with Gastric Outlet Obstruction Safely Managed by Tandem Enteral Wallstents with Excellent Outcome

A 19-year-old girl was referred by her pediatrician for post prandial vomiting and a weight loss of 11lbs over one month. On examination a 10 cm X 10 cm firm mass was felt in the epigastrium which was very tender. Laboratory data showed hematocrit of 29 and CA 125 of 65.4 (normal 35). CT abdomen had shown thickening of mid to distal stomach, with surrounding fat infiltration, peri-gastric lymph nodes, thickening of transverse colon and pelvic ascites. On EGD a thickened, nodular and infiltrated appearing stomach with narrowed antrum and near complete obstruction of the pylorus was seen. Endoscopic biopsies were inconclusive. An upper GI series revealed a 13 cm long stricture extending from the distal stomach to the duodenum. EUS showed thickening of stomach wall consistent with linnitis plastica, but FNA samples were inconclusive. On surgical exploration a large intramural mass in the distal stomach was noted along with omental lesions above the transverse colon, peritoneal implants on the fallopian tubes, and ascites. Pathology revealed a poorly differentiated gastric adenocarcinoma with abundant mucin or signet ring cell carcinoma. As the tumor was unresectable, a decision was made to bypass the gastric outlet obstruction with enteral stents. Two Wallstents (Microvasive) enteral endoprostheses measuring 90mm and 60mm in length were placed, in a tandem fashion with partial internal overlap to bypass the stricture. Patient was discharged home on a liquid and puree diet. Chemotherapy with 5-Flurouracil, Cisplatin and Tamoxifen was given as an outpatient. At a 20 week follow up, patient has good oral intake with weight gain. Outpatient follow up barium studies and CT scans have shown patent stents with good flow of dye. (figure 1)FigureGastric adenocarcinoma in young patients can present as advanced disease with metastasis and gastric outlet obstruction. Here we report one of the first cases of gastric outlet obstruction from metastatic gastric adenocarcinoma in a young patient managed with Wallstent showing feasibility, safety, and good long term patency.[figure 1]

Massive ascites secondary to ovarian schistosomiasis

Gynaecological schistosomiasis is of major public health importance and the associated clinical diagnostic difficulty has been emphasized. A case of ovarian schistosomiasis that presented with features of ovarian carcinoma was treated in our department and is here reported. A 28-year-old nulligravida presented with scanty periods anorexia weight loss and abdominal pain and distension. She looked ill and emaciated. The abdomen was grossly distended tender and contained free fluid. Abdominal-pelvic ultrasonography confirmed ascites and uterine fibroids. Laparotomy revealed multiple dark red-brown patches on the ovaries and utero-vesical peritoneum a left tubo-ovarian mass a nodular omental lesion and multiple uterine fibroids. Nine liters of ascitic fluid was drained the tubo-ovarian mass and omental lesion were removed and myomectomy performed. Complete cure was achieved after five 4- weekly courses of praziquantel (CysticideR Merck) 1600 mg in two divided doses 6 h apart and 6 months of treatment with danazol. (excerpt)

Subkostaler Einstich in der Medioklavikularlinie zur primären Insufflation und Inspektion im Rahmen der gynäkologischen Laparoskopie

Laparoscopy using subcostal insertion is particularly mentioned in the literature in connection with cholecystectomies and nephrectomies. Subcostal access was chosen for placement of the Veress needle and the primary trocar in 72 patients. The following indications have been considered: prior midline vertical abdominal incisions, previous described periumbilical adhesions, prior peritonitis, umbilical hernias, obesity. The location of the incision was subcostal of the 9th rib in the midclavicular line. 28 patients (43.1%) had periumbilical, 23 (32.0%) had subumbilical omental adhesions. Periumbilical bowl adhesions have been described for 12 patients (16.7%) and 20 (27.8) had subumbilical bowl adhesions. One patient required laparotomy. There have been no complications during the operation or postoperative in the remaining 71 patients. The subcostal insertion is a safe location for primary trocar placement and can possibly help to prevent serious omental or bowl lesions.

Malignant Peritoneal Mesothelioma Mimicking Mesenteric Inflammatory Disease

A case of malignant peritoneal mesothelioma mimicking mesenteric inflammatory disease (MID) is presented. The patient had mesenteric and omental lesions characterized at biopsy by extensive fibrosis of fat tissue with mild to moderate inflammation. One year later, post-mortem examination revealed a well-differentiated epithelial mesothelioma. Immunohistochemical stains for keratin and vimentin were diffusely positive, whereas EMA showed a membranous staining of scattered cells. CEA, Ber-EP4, B72.3 and Leu-M1 were negative. In addition, actin monoclonals decorated groups of cells pertaining to the tumoural component. Immunostains of sections from retrieved paraffin blocks of the previous biopsy showed that the bulk of the spindle-shaped and histiocytic-like cells present in the fibrous streams was strongly labeled by low-molecular-weight keratin, and coexpressed vimentin and actin. EMA showed a membranous staining of sporadic spindle and round cells. The other immunostains were invariably negative. This immunohistochemical pattern closely corresponded to the immunophenotype of the mesothelial tumour detected at autopsy and was very suggestive of myofibroblastic/submesothelial cell origin. The quantitative evaluation of silver nucleolar organizer regions (Ag-NORs) demonstrated high levels of cell proliferation in both surgical and autopsy tissue samples.

CT findings of hypervascular malignant peritoneal mesothelioma

A case of peritoneal mesothelioma is presented in which CT demonstrated abnormal regions of increased vascularity in the omentum corresponding to hypervascular omental lesions shown by angiography. This CT appearance has not been described in prior reports of CT in peritoneal mesothelioma.

346 Comparative lsctin- and immunohistochemical investigations with regard to hormone sensibility and proliperative activity of breast cancer

A case of malignant peritoneal mesothelioma mimicking mesenteric inflammatory disease(MID) is presented. The patient had mesenteric and omental lesions characterized at biopsy by extensive fibrosis of fat tissue with mild to moderate inflammation. One year later, post-mortem examination revealed a well-differentiated epithelial mesothelioma. Immunohistochemical stains for keratin and vimentin were diffusely positive, whereas EMA showed a membranous staining of scattered cells. CEA, Ber-EP4, B72.3 and Leu-M1 were negative. In addition, actin monoclonals decorated groups of cells pertaining to the tumoural component. Immunostains of sections from retrieved paraffin blocks of the previous biopsy showed that the bulk of the spindle-shaped and histiocytic-like cells present in the fibrous streams was strongly labeled by low-molecular-weight keratin, and coexpressed vimentin and actin. EMA showed a membranous staining of sporadic spindle and round cells. The other immunostains were invariably negative. This immunohistochemical pattern closely corresponded to the immunophenotype of the mesothelial tumour detected at autopsy and was very suggestive of myofibroblastic/submesothelial cell origin. The quantitative evaluation of silver nucleolar organizer regions (Ag-NORs) demonstrated high levels of cell proliferation in both surgical and autopsy tissue samples.