Biphasic synovial sarcoma of the peritoneal cavity with t(X;18) demonstrated by reverse transcriptase polymerase chain reaction

A case of a biphasic synovial sarcoma, arising on the inner surface of the anterior abdominal wall of a 13-year-old girl, is reported. Although the tumor showed rather typical histological and immunohistochemical features for synovial sarcoma, its unusual clinical presentation and anatomical location caused diagnostic difficulty, especially with regard to differentiation from a malignant mesothelioma. Applying reverse transcriptase polymerase chain reaction (RT-PCR) analysis, the SYT-SSX2 chimeric gene transcripts that result from the translocation, t(X;18)(p11.2;q11.2), found in most synovial sarcomas could be demonstrated. Thus, this RT-PCR approach is a reliable method for confirming the diagnosis of synovial sarcomas in unusual locations.

Metastatic malignant mesothelioma presenting as colonic polyps

A 66-year-old male engineer diagnosed with malignant pleural mesothelioma 4 years previously had thoracotomy, radiotherapy, and chemotherapy. He was followed regularly with chest computed tomography (CT) scan and had been asymptomatic. During one of his physical examinations, routine sigmoidoscopy showed incidental colonic polyps which were biopsied. Subsequently, recurrence of pleural mesothelioma and peritoneal involvement by mesothelioma was documented. Two of the polyps showed metastatic malignant mesothelioma in the lamina propia which strongly resembled adenocarcinoma histologically causing difficulty in making definitive diagnosis. Review of the literature disclosed no previously documented similar occurrence. This case shows the importance of clinical history and ancillary laboratory procedures such as immunohistochemistry and electron microscopy to avoid diagnostic pitfalls.

Malignant epithelial mesothelioma of the peritoneum: observations on a problem case

A 71-year-old asbestos-exposed male with symptoms suggestive of asbestosis for the previous 8 years presented with abdominal distension and ascites. Clinically, a diagnosis of mesothelioma carcinoma was made. Light microscopy of an omental biopsy failed to advance the diagnosis: The tumor was a solid, papillary, and glandular neoplasm lacking mucin and hyaluronidase-sensitive Alcian blue staining material. Immunohistochemistry gave positive results for Ber-EP4, LeuM1, and CEA, markers, favoring carcinoma. Electron microscopy revealed processes in channels and lumina, which were long, slender, and uncoated with a length: diameter ratio of 19.7. A few possessed small rootlets. A glycocalyx and glycocalyceal bodies were not seen. Other features included tonofibrils, a basal lamina, and desmosomes. The patient died 3 months following the onset of abdominal symptoms. Autopsy findings included solid and papillary tumor throughout the peritoneum, but no intrinsic tumor of the gastrointestinal tract or elsewhere. Arriving at a final diagnosis was complicated by immunohistochemistry, which favored carcinoma, and ultrastructure, which suggested mesothelioma. Taking into account all lines of evidence, it was concluded that the tumor was probably a mesothelioma but one with some features developed to an extent more typical of carcinoma.

Morphogenesis of inclusion bodies of urothelial carcinoma: a case study

The morphogenesis of inclusions of urothelial carcinoma (K. Donhuijsen et al.: Hum Pathol 23:860, 1992) is described in a case of a 51-year-old man with poorly differentiated urothelial carcinoma. Peritoneal fluid preparations contained numerous dyscohesive, large, anaplastic cells with abundant dense amphophilic cytoplasm often compartmentalized into multiple, variably sized, intracytoplasmic lumina, each containing "bull's eye"-like inclusions, with a periodic acid Schiff-positive refractile central core and an alcian blue/mucicarmine-positive rim. Ultrastructurally, the progression of osmiophilic substance from membrane-bound exocrine-type secretory granules, via exocytosis, to a presence in both intracytoplasmic lumina and extracellular space has been documented. Immunohistochemically, the periodic acid Schiff-positive refractile cores, as well as the minute periodic acid Schiff-positive granules in the cytoplasm, stained positively for secretory component and peanut agglutinins, whereas the alcian blue-positive mucinous material, which coated the refractile cores as well as the lining of the intracytoplasmic lumina, stained strongly for epithelial membrane antigen and leu M1. Ultrastructurally, protein A-gold probes, immunolabeled for peanut agglutinin and secretory component, were localized to the osmiophilic substance.

Endometrial stromal sarcoma with focal smooth muscle differentiation: recurrence after 17 years: a follow-up report with discussion of the nomenclature

In 1977, a case report was published describing a 28-year-old women with an endometrial stromal tumor that showed foci of myogenic differentiation. The term "stromomyoma" was introduced to encompass both this type of neoplasm as well as "uterine neoplasms resembling ovarian sex-cord tumors" (UTROSCTs). More than 17 years later, the tumor recurred, involving the right ovary, sigmoid colon, small bowel, abdominal wall and omentum. The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed. Applying the recent classification and diagnostic criteria of endometrial mesenchymal neoplasms, we have concluded that this tumor was a low-grade endometrial stromal sarcoma (LGSS). The formerly proposed term "stromomyoma" implies a benign tumor, in contrast to the obviously malignant nature of this particular tumor. Focal myogenic differentiation of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarcomas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.

Multinucleated giant stromal tumor of the omentum: report of a case with immunohistochemical and ultrastructural investigation

Multinucleated giant stromal cells (MGSC) have been described in a variety of lesions of various anatomical sites. They are generally believed to be derived from fibroblasts or myofibroblasts. Their size and bizarre appearance may lead to an erroneous interpretation of infiltrating malignant cells, but they are regarded as reactive in nature. MGSC also seem to participate in a neoplastic process and form a part of tumors called giant cell fibroblastomas (GCF). In GCF, multinucleated giant cells are sparsely scattered throughout the tumor, which is composed of loosely arranged spindle cells. Thus far, no tumor composed of MGSC entirely, to the best of the authors' knowledge, has been reported. This study involved an 80-year-old female with an omental tumor, which is believed to represent the first case of tumor of MGSC. The patient developed abdominal pain; a large abdominal tumor measuring 18 x 15 x 5 cm by computerized tomography was found located between the left lobe of the liver, the transverse colon, and the greater curvature of the stomach. Although the tumor was adherent to the above organs and infiltrating the omentum, it was resectable. Grossly, the tumor was highly vascular and the surface was shaggy with no recognizable capsule. The cut surfaces were red to tan with frequent cystic spaces containing bloody material. Microscopically, the tumor cells were large and multinucleated (2-6 nuclei) with prominent nucleoli. The cytoplasm was abundant and stained amphophilic. These tumor cells formed moderately cellular sheets filling the spaces between the varying sized vessels. There was prominent vascularity throughout the tumor. DNA study by image analysis revealed aneuploidy peaks. On immunohistochemistry, the tumor cells were strongly positive for vimentin, moderately positive for actin along the periphery of the cytoplasm, and negative for cytokeratin, EMA, myoglobin, S-100, CEA, Factor XIIIa, HMB-45, and HAM56 and KP-1. Ultrastructurally, the cytoplasm contained rich profiles of RER with scattered lysosomes. The cell borders were slightly irregular with occasional subplasmalemmal densities facing loosely arranged collagenous stroma. The light microscopic, immunohistochemical, and electron microscopic features of tumor cells were remarkably similar to MGSC. The tumor size and gross appearance suggested a malignancy, but it was a diploid tumor and the patient remains disease free 5 years after a complete resection.

Localized and diffuse mesotheliomas of the genital tract and peritoneum in women. A clinicopathologic study of nineteen true mesothelial neoplasms, other than adenomatoid tumors, multicystic mesotheliomas, and localized fibrous tumors

Peritoneal mesotheliomas are rare in women, compared to serous epithelial neoplasms with which they are often confused. We evaluated the clinicopathologic features of 19 true mesothelial neoplasms affecting the genital tract or peritoneum of women (other than adenomatoid tumors, benign multicystic mesotheliomas, and localized fibrous tumors) to characterize their clinicopathologic features and to determine their clinical behavior. Six tumors were localized to one anatomic site at presentation, and 13 involved more than one anatomic site. The six localized tumors were solitary, small (0.8-2.0 cm), polypoid or nodular lesions, five of which were incidental findings. All had a predominantly tubulopapillary pattern, either pure or mixed with adenomatoid-like or small solid foci. Nuclear grade ranged from 0 to 2. Mitotic figures (MF) were absent in two tumors. The mitosis count in the other four tumors was < 1 MF/10 high-power microscopic fields (HPF) (average method) and ranged from 1 to 3 MF/10 HPF (highest count method). Five patients were alive without recurrence after postoperative intervals ranging from 19 months to 9 years (median, 5 years); one patient died of metastatic gastric carcinoma at 14 months. Thirteen tumors involved more than one anatomic site and were classified as diffuse mesothelioma. Typically, these tumors were symptomatic and accompanied by ascites. The tumors had either a plaque-like or endophytic configuration. Eleven were purely epithelial mesotheliomas, and two had a minor sarcomatoid component. Tubulopapillary patterns were present in 10 tumors, usually admixed with focal adenomatoid-like or solid patterns, and three had a purely solid pattern. All 13 tumors had grade 3 nuclei. The mitosis count ranged from < 1 to 2 MF/10 HPF (average count method) with a range of 1-4 MF/10 HPF by the highest count method. Immunohistochemically, 13/13 tumors stained for cytokeratin (AE1/AE3). None were immunoreactive for polyclonal carcinoembryonic antigen (CEA), Leu-M1, or B72.3. One diffuse mesothelioma stained focally for Ber-EP4, and electron microscopy confirmed the mesothelial nature of this tumor. Nine patients died of tumor after postoperative intervals ranging from 1 month to 6 years. Eleven patients had received postoperative adjuvant intraperitoneal or systemic chemotherapy. One patient died with increased abdominal girth 8 years after operation and one course of intraperitoneal chemotherapy, though the role of mesothelioma in her death was uncertain. One patient was alive with diffuse tumor and persistent ascites 25 months after six courses of intraperitoneal chemotherapy. One patient was alive without evidence of disease 4 months after two courses of systemic chemotherapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Mucinous borderline and malignant tumors of the ovary. A clinicopathologic and DNA ploidy study of 92 cases

BACKGROUND

The morphologic spectrum of ovarian mucinous tumors is well known, but the features that predict aggressive behavior are still controversial.

METHODS

Ninety-two cases of primary ovarian mucinous tumors with atypical epithelial proliferation and/or stromal invasion were analyzed histologically and by DNA flow cytometry, and the results were correlated with clinical findings.

RESULTS

The authors reviewed 57 intestinal mucinous borderline tumors (IMBT), 3 endocervical-like mucinous borderline tumors (EMBT), 21 noninvasive mucinous carcinomas (NIMC), and 11 invasive mucinous carcinomas (IMC). The 5-year survival rate for Stage I tumors was: IMBT 100%, EMBT 100%, NIMC 94% and IMC 60%. The 5-year survival of Stage II-IV tumors was: IMBT 50%, NIMC 33% and IMC 0%. Forty-four IMBTs were diploid, and 4 were aneuploid. All six high stage IMBTs were diploid. Two EMBTs were diploid, and one was aneuploid. There were seven diploid, four polyploid, and six aneuploid NIMCs. Two of the three lethal NIMCs were aneuploid. Four IMCs were diploid, and four were aneuploid. Of these, only the diploid Stage I IMCs were nonlethal. All NIMCs that recurred or presented with metastases had been sampled inadequately. High stage tumors with pseudomyxoma peritonei (PP)-type lesions often were associated with pseudomyxoma ovarii of the cellular type.

CONCLUSIONS

Mucinous tumors with stromal invasion or presenting with PP had a definite malignant behavior. All other atypical mucinous tumors, when confined to the ovary and optimally sampled, had an excellent prognosis. DNA ploidy analysis may prove useful in determining the risk of progression, especially in Stage I IMCs.

Intra-abdominal desmoplastic small round cell tumor of the peritoneum in a young man

The desmoplastic small round cell tumor (DSRCT) has a predilection for involvement of the peritoneal surfaces of young adult men. The tumor has an extremely poor prognosis: despite aggressive therapy the patients usually die of disease within the first 2 years following diagnosis. The present report details the pathologic features of a pelvic tumor, which proved to be a DSRCT, arising in a previously healthy 24-year-old man. The light microscopic features were typical of a DSRCT--the tumor cells were small and round, had inconspicuous cytoplasm, and were grouped into distinctive islands and cords that were dispersed in a fibrous stroma. The immunohistochemical features were likewise characteristic of DSRCT in that the tumor cells were positive for cytokeratin, vimentin, epithelial membrane antigen, and desmin. Ultrastructurally, the tumor cells were distinguished by an abundance of intercellular junctions, cytoplasmic lipid droplets, cytoplasmic intermediate filaments, and an absence of surface microvilli. Recognition of this tumor type is important in view of both its clinical features (extremely poor prognosis despite therapy) and its potential to shed some light on the nature of the family of lesions that has traditionally been classified by light microscopists as small round cell tumors.

Two cases of "multicystic peritoneal mesothelioma": description and critical review of the literature

Two cases of multicystic peritoneal mesothelioma (MPM) are reported. Ultrastructural and immunohistochemical techniques confirmed the mesothelial nature of the lesion. The biologic and clinical behaviour, pathogenesis and differential diagnoses of this rare pathology are discussed. Although regarded as a neoplasm, many analogies seem to link MPM to fibromatoses and other non-neoplastic lesions, suggesting a reactive hyperplastic process. The relationships between mesothelium and the secondary Müllerian system, to date not fully investigated, are stressed and a classification of the coelomatic reactive and neoplastic processes, both metaplastic (müllerian metaplasia) and non-metaplastic, is suggested.

Malignant peritoneal mesothelioma: a case report

Malignant peritoneal mesothelioma is a rare disease, not previously reported in Taiwan. The reported case concerns a 64-year-old veteran who had suffered from abdominal pain and distension for several days. After exploratory laparotomy, segmental resection of the small intestine, excised a mesenteric mass. A characteristic biphasic pattern resulting from the admixture of gland-like area and a sarcomatous stroma presented in the histologic section. A series of histochemical, immunohistochemical and ultrastructural studies proved this to be a malignant peritoneal mesothelioma. The patient died after a course of post-operative chemotherapy. History of asbestos exposure, with which the tumor is usually intimately associated, could not be traced with certainty. Poor prognosis is the rule of the disease; almost all patients die within two years of diagnosis. An effective therapeutic modality is still unavailable. Here the clinical and pathologic characteristics of the tumor are described, with a brief review and discussion of the pathogenesis as well as the obscured therapeutic problem.

A study of surface property changes in rat mesothelial cells induced by asbestos using aqueous two-phase polymer solutions

Intraperitoneal (i.p.) injection of crocidolite asbestos was used to induce mesotheliomas in rats. The morphological changes of the mesothelial cells were studied by light and electron microscopy and by cytologic examination of peritoneal washings. After injection, the asbestos fibres stimulated an acute inflammatory response and were rapidly phagocytosed by the mesothelial cells and incorporated into the submesothelial tissues. At 7 days, the normal microvillous surface of the mesothelium was replaced with a syncytium of proliferating mesothelial cells showing extensive loss of microvilli. Nine months or so later, multifocal mesothelial tumours arose within the peritoneal cavity. The surface thermodynamic properties of normal, asbestos-stimulated mesothelial cells and of mesothelial tumour cells in culture were studied using an aqueous two-phase system containing 4% Dextran T-2000 and 4% poly (ethylene glycol) (PEG) w/w. After asbestos stimulation, there was a significant (P < 0.01) increase in contact angle between the dextran-rich phase and the mesothelial cell surface. These changes were even greater for the mesothelial tumours. The results indicate that the work of adhesion for asbestos-stimulated mesothelial cells and mesothelial tumours is lower than in normal tissue. These findings may be relevant to the process of tumour spread in the serosal cavities and to the development of distant metastases.

Abnormal renovascular impedance in patients with hepatic cirrhosis: detection with duplex US

The purpose of this study was to determine whether duplex ultrasound (US) can allow detection of early impairment of renal function in patients with hepatic cirrhosis. The authors calculated the pulsatility index (PI) and resistive index (RI) by using duplex US in 17 patients with cirrhosis and ascites but with normal renal function (group A), in 16 patients with cirrhosis but no ascites (group B), in 20 with chronic hepatitis (group C), in six with peritoneal carcinomatosis (group D), and in 16 healthy control subjects (group E). All patients had normal renal function on the basis of blood urea nitrogen and serum creatinine values. PI and RI were higher (P < .001) in group A patients than in others. Cirrhotic patients with ascites had renal vasoconstriction even in the absence of clinically apparent renal impairment and full-blown hepatorenal syndrome. Impaired renal perfusion plays a key role in sodium and fluid accumulation in patients with liver disease. On the basis of these results, duplex US is useful in pathophysiologic and clinical studies in such patients.

Intra-abdominal desmoplastic small round cell tumor

A rarely encountered but distinctive type of aggressive malignant tumor of childhood and adolescence has been recently described as occurring predominantly or exclusively intrabdominally. It is characterized by a generally diffuse pattern of growth of small cells with hyperchromatic nuclei, scanty cytoplasm, patchy epithelial differentiation, immunohistochemical co-expression of keratin and desmin intermediate filaments and a focal but pronounced desmoplastic stromal component. It is regarded as yet another variant in the group of small round cell tumors (SRCT) of infancy and childhood. This case report of a mass in the greater omentum of a 15 yr-old girl adds to the 33 cases already described in the English literature.

Morphometric differentiation between responsive tumor cells and mesothelial hyperplasia in second-look operations for ovarian cancer

We developed a procedure based on computerized image analysis to establish objective criteria for the differential diagnosis between mesothelial hyperplasia and cancer in peritoneal tissue samples obtained at second-look operations for ovarian cancer. The tumor tissue after chemotherapy was classified as "nonresponsive" if it was found by histologic criteria to be roughly similar to the tumor before chemotherapy and as "responsive" if it was found to be different (small clusters of bland-looking cells with no mitotic activity). Eighty-five samples of tissue had been classified previously by a pathologist into one of the four following groups: ovarian tumor prior to chemotherapy, "responsive" tumor, "nonresponsive" tumor, or mesothelial hyperplasia. Cell profiles of the tissue samples were studied by computerized image analysis using 21 morphometric descriptors derived from the manual tracings of tumor nuclei, including nuclear perimeter, nuclear area, maximal chord, circularity factor, and standard deviations of these descriptors. Size distribution curves of nuclear areas and maximal chords were included in the analysis. A multivariate discriminant analysis confirmed the separation into the four diagnostic groups, accomplished with consideration of the physical descriptors alone, except for some overlapping between groups 1 and 3. The separation between carcinoma and mesothelial hyperplasia was clear in all cases.

Disseminated leiomyomatosis peritonealis: report of a case in a postmenopausal woman

Disseminated leiomyomatosis peritonealis (DLP) is a rare condition that to date has been reported only in premenopausal women. The author reports a case of DPL occurring in a postmenopausal woman who had undergone total hysterectomy 30 years before and had received no hormonal therapy subsequently. The lesions were multiple and consisted of smooth-muscle cells that proliferated from medium-sized blood vessels. The author concludes that the patient's lesions likely represent a histologic variant of DLP.

Multicystic peritoneal mesothelioma in a Fischer-344 rat

A spontaneous multicystic peritoneal mesothelioma was detected in a 108-wk-old male Fischer-344/DuCrj rat. Grossly, a tumor containing numerous, semi-transparent, variously sized, thin-walled cysts was found on the splenic serosal surface. Microscopically, each cyst was surrounded by variable amounts of loose connective tissue. The luminal and free surfaces of the cysts were covered by a single layer of flattened or cuboidal mesothelial cells. No metastases were detected in any of the other organs. Diagnosis was supported by immunohistochemistry and ultrastructural features.

Intra-abdominal desmoplastic small-cell tumours with divergent differentiation. Report of two cases and review of the literature

Two intraabdominal desmoplastic small cell tumours presenting in young adult males and involving the entire peritoneum, with no evident single primary site, have been studied. The histological pattern was suggestive of a metastatic small cell epithelial neoplasm, but immunohistochemical study revealed strong reactivity for cytokeratins, vimentin and desmin indicating synchronous epithelial and myogenous differentiation. In addition epithelial membrane antigen and neuron specific enolase were also positive. Electron microscopy showed fairly undifferentiated tumour cells with striking desmosome-like junctions, containing prominent paranuclear whorls of intermediate filaments, and a typical myofibroblastic stroma around neoplastic islands. Although the histogenesis of these recently described and rare tumours still remains uncertain, it seems that they constitute a reproducible entity which requires differential diagnosis from other small cell tumours of childhood and young adulthood.

Diagnostic criteria for human diffuse malignant mesothelioma

Diffuse malignant mesothelioma is a rare tumor in the general population, yet is unique in that it is caused almost exclusively by exposure to asbestos with long-term latency (15 years and over). Pathologists are required to provide a reliable diagnosis of the tumor for clinicians who are responsible for the treatment of affected patients. Pathological diagnosis of diffuse malignant mesothelioma is not always easy; however, it has improved over the last few decades. Currently, comprehensive analysis, including gross appearance, histology, histochemistry, immunocytochemistry and electron microscopy is recommended as the best approach to an accurate diagnosis of diffuse malignant mesothelioma.

Primary round cell liposarcoma of the omentum. A case report

Liposarcomas are the most common of the malignant soft tissue tumors arising in the mediastinum and retroperitoneum. We have treated patients for round cell liposarcoma, an unusual histologic subtype, which is reported to be histologically mistaken for Ewing's sarcoma, lymphoma and other round cell neoplasms. The successful resection of a 2,300-g round cell liposarcoma of the omentum was recently performed at our hospital. Ultrastructural observations of this tumor are characterized by massive proliferation of the mitochondria in addition to the presence of lipid vacuoles in tumor cells. To our knowledge, no description of substantial mitochondrial proliferation in round cell liposarcoma has appeared previously in the literature; therefore, this is the first case report of histopathologic, cytopathologic and electron microscopic observations on this extremely rare tumor.

Quantitative analysis of nucleoli and nucleolar organizer regions in cultured primary human normal, reactive and malignant mesothelial cells

The number and the size of silver-stained intranuclear granules, which correspond to the nucleolus and nucleolar organizer regions, have been determined by means of quantitative methods in cultured primary human mesothelial cells obtained from normal, reactive and malignant mesothelium. The mean values per nucleus of the number, the total area, the average area, and the relative area of the silver-stained granules and the mean nuclear area were determined for each of the three conditions. Normal, reactive and malignant mesothelial cells differed significantly in all the features. These findings at the optical level reflect the differing rate of the nucleolar biosynthetic activity related to the different biological properties of the three cell types, and the features can be useful morphometric descriptors in the diagnostic pathology of the mesothelium.

Primary papillary serous tumor of the peritoneum. Report of a case

In the present report we describe a rare papillary serous tumor of the peritoneum occurring in a woman without evidence of ovarian neoplasia. Histochemical, immunohistochemical and ultrastructural findings are reported, with particular emphasis on electron microscopic results and on their importance in the differential diagnosis with malignant mesotheliomas.