Biomedical subjects

Masazumi Tsuneyoshi

Publications and source records attributed to Masazumi Tsuneyoshi.

At least 127 records · Page 7Linked to original sources

PubMed2002

Intracellular distribution of intermediate filaments in vimentin-positive gastric carcinomas: confocal laser scanning microscopy using formalin-fixed paraffin-embedded specimens.

Intermediate filaments are known as cytoskeletal elements. Recently, additional vimentin expression has been reported in some carcinomas; however, the function of such expression remains unclear. We studied the intracellular distribution of low-molecular weight cytokeratin and vimentin by immunohistochemistry in 17 vimentin-positive gastric carcinomas using confocal laser scanning microscopy. All materials were formalin-fixed and paraffin-embedded. Low-molecular weight cytokeratin expression showed a membranous pattern with a prominent deposition just below the cytoplasmic membrane in both tubular and solid components of the carcinomas. This unique membranous deposition was frequently absent in diffuse components. On the other hand, vimentin expression showed a fibrillary pattern in all components and also showed a unique basal distribution in the tubular components. We also recognized an aggregate pattern of the intermediate filament expression in diffuse components. We conclude that the significance of vimentin expression in carcinoma cells cannot be explained as a simple substitution for low-molecular weight cytokeratin because the distribution of vimentin and low-molecular weight cytokeratin is different.

Adenocarcinoma↗

PubMed2002

Phenotypic expression of gastrointestinal differentiation markers in colorectal adenocarcinomas with liver metastasis.

AIM: The purpose of the present study was to clarify the correlation between phenotypic expression of gastrointestinal differentiation markers and colorectal cancer behaviour, particularly invasion and hepatic metastasis. METHODS: Thirty-one cases of advanced colorectal adenocarcinoma (CRC) with liver metastasis were selected. Phenotypic patterns were evaluated immunohistochemically by means of antibodies to CD10, MUC2, and human gastric mucin (HGM). RESULTS: The incidence of MUC2 (45.2%) and HGM (16.1%) expression in CRCs with liver metastasis did not differ from non-metastatic CRCs. In contrast, the incidence of CD10 expression was significantly higher in CRCs with liver metastasis (58.1%) than in control CRCs (21.7%). Phenotypic expression in the liver metastasis carcinomas was similar to that of the primary lesions. CONCLUSIONS: The findings suggest that cases of CRC with CD10 expression are at increased risk of liver metastasis. Even if there is no liver metastasis at laparotomy for CRC, careful follow-up is recommended for CRCs with CD10 expression.

Adenocarcinoma↗

PubMed2002

Malignant transformation of renal angiomyolipoma: a case report.

We report a case of renal angiomyolipoma (AML) with malignant transformation. A 28-year-old woman developed large bilateral renal masses 5 months before admission to our hospital. She was diagnosed with tuberous sclerosis when she was 4 years old. Total nephrectomy of the left kidney was performed, but she died during the operation. Although the focal region of the resected tumor had the appearance of a classic AML, most of the lesion showed a diffuse proliferation of atypical epithelioid cells resembling that in renal cell carcinoma. The epithelioid cells had extremely pleomorphic and hyperchromatic nuclei with frequent mitotic figures, including atypical forms. Immunohistochemical analysis revealed that the atypical epithelioid cells and the typical AML lesions were both positive for HMB-45 but that the former were negative for epithelial and myogenic markers. The smooth muscle cells and thick-walled vessels were focally positive for muscle-specific actins. Furthermore, the atypical epithelioid cells were immunoreactive for p53, whereas the foci of the typical AML were negative. Examination of the microdissected paraffin-embedded tissues revealed p53 mutations in the malignant epithelioid areas in AML but not in the renal parenchyma or typical AML areas. In this case it is proposed that p53 mutation may play an important role in malignant transformation of renal AML.

Actins↗

PubMed2002

Molecular analysis of p53, MDM2, and H-ras genes in osteosarcoma and malignant fibrous histiocytoma of bone in patients older than 40 years.

Some investigators have reported that the histological features of osteosarcoma (OS) arising in elderly patients are different from those in younger patients; however, a molecular biologic study of OS in elderly patients has not been documented. In this study, 23 cases of OS (15 osteoblastic and 8 MFH-like types) and 18 cases of MFH of bone in patients 40 years of age or older were analyzed for mutation of the p53 gene, amplification of the MDM2 gene, and mutation of the H-ras gene, using formalin-fixed paraffin-embedded materials. We also examined the expression of p53, MDM2, and p21WAF1 protein immunohistochemically and assessed the proliferative activities using the monoclonal antibody MIB-1. p53 immunoreactivity was recognized in 5 of 23 OS cases (22%), whereas p53 gene mutations were also detected in 5 of 23 OS cases (22%; osteoblastic [4/15; 27%] and MFH-like [1/8; 18%] types) and in 4 of 18 cases of MFH of bone (22%). There was a statistically significant correlation between p53 immunoreactivity and p53 mutation status in OS (P =.0482). All those cases of osteoblastic OS and MFH of bone that had p53 mutations, with the exception of one case of MFH of bone that had a silent mutation, showed aggressive biologic behavior (dead of disease within 12 mo), in contrast to the MFH-like OS cases (alive without disease at 22 mo). Three cases of OS (13%) and three cases of MFH of bone (17%) showed immunoreactivity for MDM2. As for gene alteration, three cases of OS (13%) and 3 cases of MFH of bone (17%) demonstrated MDM2 amplification. MDM2 amplification showed a significant correlation with the expression of MDM2 protein in OS (P =.0344). p21WAF1 expression was detected in three cases of OS (13%) and in six cases of MFH of bone (33%). MDM2 alteration and p21WAF1 expression were not observed in any of the cases of MFH-like OS. MIB-1-LI showed a statistically significant correlation with p53 immunoreactivity and MDM2 immunoreactivity in OS (P =.0307 and P =.0358, respectively). H-ras mutation at Codons 12 and 13 was not recognized in any of the cases of OS or MFH of bone. In conclusion, although treatment differences during the time of study make it difficult to compare survival analysis, in the current study, p53 mutation in osteoblastic OS and MFH of bone in elderly patients seemed to be closely associated with the progression of the tumor, which was not the case in MFH-like OS. Furthermore, MDM2 alteration and p21WAF1 expression were demonstrated only in osteoblastic OS and MFH of bone, whereas they were not recognized in MFH-like OS. Although the number of patients in this analysis was small, it would appear that MFH-like OS may have some characteristic biologic aspects when compared with osteoblastic OS and MFH of bone in elderly patients.

Adult↗

PubMed2002

The utility of keratin 903 as a new prognostic marker in mass-forming-type intrahepatic cholangiocarcinoma.

The cytokeratins phenotype is largely preserved during neoplastic transformation and tumor development. We evaluated the immunoreactivity of biliary epithelial markers keratin 903 and cytokeratin 7 and 19 for intrahepatic cholangiocarcinoma, and compared the results with those for biliary dysplasia and hepatocellular carcinoma. Reactivity with keratin 903 was weakly expressed and increased after the expression of cytokeratin 7 and 19 during human intrahepatic bile duct development. More than 80% of cases of biliary dysplasia showed positive reactivity with keratin 903. Of the 30 cases of hepatocellular carcinoma, 3 (10%), 6 (20%), and 1 (3%) showed positive reactivity with Keratin 903 and cytokeratin 7 and 19, respectively. Among the 73 cases of intrahepatic cholangiocarcinoma, 54 (74%), 66 (90%), and 61 (84%) showed positive reactivity with keratin 903 and cytokeratin 7 and 19, respectively. On clinicopathologic examination of intrahepatic cholangiocarcinomas, reduced keratin 903 reactivity was significantly higher in tumors with an expansive growth pattern (P <.0001), in those with medullary-type stromal reaction (P =.0327), in those without perineural invasion (P =.0001), and in those without lymph node metastasis (P =.0015). In addition, the reactivity with Keratin 903 was directly correlated with expression of cytokeratin 7 and 19 (P =.0153 and P <.0001, respectively). Cases showing reduced keratin 903 reactivity were characterized by a distinctive morphology indicating an hepatocellular carcinoma-like pattern. Multivariate analysis of overall survival revealed that keratin 903 reactivity was a significantly independent prognostic factor. In conclusion, patients with intrahepatic cholangiocarcinoma showing reduced keratin 903 reactivity had a favorable prognosis. Remarkably, the cytokeratin phenotype of intrahepatic cholangiocarcinoma was correlated with the morphologic appearance of intrahepatic cholangiocarcinoma.

Aged↗

PubMed2002

The role of thymidine phosphorylase and thrombospondin-1 in angiogenesis and progression of intrahepatic cholangiocarcinoma.

Thymidine phosphorylase (TP), an important regulator of angiogenesis, is correlated with progression, metastasis, and prognosis in various types of tumor. In contrast, both positive and negative effects of thrombospondin-1 (TSP-1) on angiogenesis have been reported. In the present study, we examined the expression of TP and TSP-1 in carcinoma cells in 67 primary intrahepatic cholangiocarcinomas (ICCs) immunohistochemically and its correlation with angiogenesis, clinicopathological features, and prognosis. Twenty-six (38.8%) cases were classified as exhibiting positive TP expression. TP expression showed a significant correlation with vascular invasion, lymphatic permeation, perineural invasion, and lymph node metastasis. Thirty-four (50.7%) cases were classified as exhibiting positive TSP-1 expression. TSP-1 expression was significantly correlated with only lymphatic permeation. The microvessel count in positive TP expression cases was significantly higher than that in negative cases. In contrast, the microvessel count in negative TSP-1 expression cases was significantly higher than that in positive cases. Survival in patients who were positive for both TP and TSP-1 expression was significantly poor. Our results suggest that the increased TP expression and decreased TSP-1 expression contribute to angiogenesis, but that the role of angiogenesis in ICC is not closely related to tumor aggressiveness. The TP and TSP-1 expression in ICC may enhance tumor aggressiveness.

Bile Duct Neoplasms↗

PubMed2002

Detection of angiotensin-converting enzyme gene insertion/deletion polymorphism from paraffin-embedded tissues: the Hisayama study.

Previous studies have suggested that archival materials from formalin-fixed paraffin-embedded blocks are unsuitable for most molecular techniques because the extracted DNA can be severely degraded. Therefore, the present study was designed to investigate the accuracy of genotyping for the insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene from paraffin-embedded tissues of autopsy cases from Hisayama Town, Japan. The genotype was determined using the double polymerase chain reaction method and to test the accuracy of the method, the polymorphism was investigated using paraffin-embedded tissues from 18 cases whose ACE genotypes (6 cases for each genotype) were known in advance from analysis of fresh-frozen tissue samples. Genotyping using paraffin-embedded tissues was then determined for 968 autopsy subjects. The genotype could be determined in 16 of the 18 test samples (88.9%) and there was no discrepancy with the results obtained from the fresh-frozen tissues. Of the 968 autopsy cases, the frequency of the DD, ID, and II genotypes was 12.4%, 47.3%, and 40.3%, respectively, a distribution that did not deviate from the Hardy-Weinberg equilibrium (chi(22df )= 0.67, p=0.72). These findings suggest the accuracy of the present method of ACE genotyping from paraffin-embedded tissues.

Autopsy↗

PubMed2002

Severe pulmonary hypertension in a patient with systemic lupus erythematosus and minimal lupus activity.

Pulmonary hypertension (PH) sometimes occurs in patients with systemic lupus erythematosus (SLE). We report a case of 51-year-old-woman with PH associated with SLE. She had been diagnosed as SLE on the basis of pericardial effusion, hematological disorder, positive antinuclear antibody, and hypocomplementemia. Despite minimal lupus activity, she had marked elevation of pulmonary arterial pressure (101/53 mmHg) and decreased cardiac index (1.5 l/min/m2). Symptoms related to PH were progressive under treatment with oral corticosteroids, oxygen, calcium antagonists, and warfarin. After 17 months of epoprostenol treatment, she died of pulmonary infarction. SLE-associated PH is often severe and progressive even in association with minimal activity.

Anticoagulants↗

PubMed2002

Beta-catenin accumulation and gene mutation in exon 3 in dedifferentiated liposarcoma and malignant fibrous histiocytoma.

CONTEXT: beta-Catenin is an adhesion molecule that also plays a role in the Wnt signaling pathway. Objective.-To analyze beta-catenin mutation and accumulation in a series of liposarcomas and malignant fibrous histiocytomas. DESIGN: beta-Catenin mutation in exon 3 was studied using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing analysis in 30 formalin-fixed, paraffin-embedded liposarcomas. The tumors included 12 dedifferentiated liposarcomas, characterized by both high-grade anaplastic components and well-differentiated liposarcoma components, plus 18 well-differentiated liposarcomas (10 lipoma-like and 8 sclerosing-type cases). The 2 components of dedifferentiated liposarcomas were analyzed independently. beta-Catenin accumulation in the nuclei or cytoplasm and Ki-67 expression (cell-proliferation marker, MIB-1 labeling index) were examined immunohistochemically. Nine storiform-pleomorphic-type malignant fibrous histiocytomas were also studied. RESULTS: Dedifferentiated liposarcomas showed mutation in 2 cases (17%) and accumulation in 5 cases (42%). One of the 2 cases that showed mutations had a mutation in the well-differentiated component; this mutation was silent. The other case had mutations that differed between the 2 components. In well-differentiated liposarcomas, mutation was not seen in any of the cases (0/18; 0%); however, accumulation was seen frequently in the sclerosing-type cases (5/8; 63%), but not in the lipoma-like cases (0/10; 0%). Malignant fibrous histiocytomas showed mutation and accumulation in 5 (56%) and 4 (44%) cases, respectively, without any exact correlation between the cases. Cases with accumulation had a higher MIB-1 labeling index than those without, among both the sclerosing-type well-differentiated liposarcomas (P <.05) and the malignant fibrous histiocytomas. CONCLUSIONS: Our results suggest the possible involvement of beta-catenin activation caused by beta-catenin mutation in liposarcoma and malignant fibrous histiocytoma, but the contribution would seem to be different, depending on the tumor type. beta-Catenin accumulation is also thought to be related to cell proliferation in some of the cases.

Adult↗

PubMed2002

ATP-binding cassette superfamily transporter gene expression in human primary ovarian carcinoma.

PURPOSE: The purpose of this study is to attempt to characterize patients with unfavorable clinical outcome by the relative mRNA levels of ABC transporter expression in their tumor samples and to examine whether relative mRNA levels of each of the ABC transporters can be a useful predictor of progression-free survival in advanced ovarian carcinoma. EXPERIMENTAL DESIGN: We examined tumor samples taken from 30 patients with primary serous papillary adenocarcinoma of the ovary for the expression of MDR1 and MRP1, MRP2, and MRP3 mRNA by using real-time reverse transcription-PCR, and we evaluated its correlation with clinical outcome. All 30 patients were divided into three groups according to clinical outcome after debulking surgery and platinum-based chemotherapy: 8 patients were classified into the unfavorable group; 11 were classified into the favorable group; and 11 were classified into intermediate group. RESULTS: The relative mRNA levels of MRP1 and MRP3 were significantly different among the three groups, and the mRNA levels of MRP1 and MRP3 in the unfavorable group were significantly higher than those in the favorable group by multiple comparison. The relative mRNA levels of MRP1 expression were significantly correlated with those of MRP3 expression. In the 30 patients with serous papillary adenocarcinoma, univariate and multivariate analysis demonstrated that the high relative mRNA levels of MRP1 expression were significantly correlated with a short period of progression-free survival. CONCLUSIONS: In patients with advanced ovarian serous papillary adenocarcinoma, these results suggest that patients with an unfavorable clinical outcome are characterized by increased levels of coordinated MRP1 and MRP3 mRNA expression in their tumor samples. Furthermore, a higher level of MRP1 mRNA expression can be a candidate for a useful predictor of a shorter period of progression-free survival.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

The Incidence of Apoptosis During Colorectal Tumorigenesis.

Epithelial homeostasis in colorectal tumorigenesis is dependent not only on the rate of cell production but also on the rate of apoptosis, a genetically programmed process of autonomous cell death. Ideally, an analysis of cell kinetics should be carried out for both cell proliferation and death. We investigated the incidence of apoptosis in 35 colorectal neoplasms (15 adenomas and 20 carcinomas) using the DNA nick end labeling method (TUNEL). The expression of Ki-67 as a marker of proliferating activity and some kinds of oncogene products were analyzed immunohistochemically. When the TUNEL labeling index (TI) and the Ki-67 labeling index (KI) were determined, TI was found to be significantly higher in adenomas with high-grade dysplasia (TI: 2.5%) than in adenomas with low-grade dysplasia (TI: 0.6%) or carcinomas (TI: 1.4%). In contrast, KI increased with the progression of colorectal tumorigenesis. Moreover, TI of the carcinomas was significantly higher in c-Myc-positive cases than in c-Myc-negative cases (p<0.05). The results indicate that apoptosis plays an important role in the early stage of the adenoma-carcinoma sequence, permitting us to speculate that the increased tumor cell proliferation is negated by increased apoptosis at the stage of adenoma with high-grade dysplasia (or intramucosal carcinoma), while cell proliferation overwhelms cell death at the stage of invasive carcinoma. Int J Surg Pathol 8(2):123-132, 2000

Journal Article↗

PubMed2000

Extraskeletal Myxoid Chondrosarcoma with Rhabdoid Features, with Special Reference to Its Aggressive Behavior.

The presence of rhabdoid cells has been reported in various types of malignant neoplasms. Thirty-six cases of extraskeletal myxoid chondrosarcoma (EMC) were reviewed, and three of them revealed rhabdoid features. These cases contained cells having prominent eosinophilic globular cytoplasm, but were otherwise typical of EMC. Immunohistochemically, cytokeratin (CAM 5.2) was positive in three of 20 cases (15%), including two of the three with rhabdoid features. The rhabdoid cells were also immunostained with vimentin. The 5-year survival rate in the 26 cases with follow-up information was 73%, and the 10-year survival rate was 63%. The cases with rhabdoid features had a significantly poorer prognosis (p=0.0271). This study suggests that presence of rhabdoid features is a predictor of aggressive behavior in EMC, as it was shown to be in other mesenchymal neoplasms. Int J Surg Pathol 8(2):145-152, 2000

Journal Article↗

PubMedDate not supplied

Synovial sarcoma of the thyroid. Report of a case with aspiration cytology findings and gene analysis.

BACKGROUND: Synovial sarcoma, generally known as a soft tissue tumor, can also occur in the head and neck region, including the thyroid gland. Cytologic findings are important to differentiate the tumor from other types of neoplasms arising in the thyroid gland. CASE: A 60-year-old man complained of hoarseness. A palpable neck tumor was detected, and a computed tomography scan showed a thyroid tumor accompanied by destruction of the thyroid and cricoid cartilage. The results of a preoperative fine needle aspiration biopsy showed numerous spindle cells with pale cytoplasm and oval nuclei with fine, granular chromatin, all of which suggested a medullary carcinoma. The extirpated thyroid tissue weighed approximately 120 g, and a grayish white, elastic, solid tumor (6.8 x 6.5 cm) was present in the left lobe. Histologically, fasciculation of spindle cells that had proliferated solidly and densely was observed. Also, the expression of a chimera gene, SYT-SSX, was detected in the tumor tissue. CONCLUSION: Synovial sarcoma of the thyroid is extremely rare, and its diagnosis by fine needle aspiration biopsy is generally considered very difficult. The detailed cytologic findings observed here might be helpful with the differential diagnosis of thyroid neoplasms.

Biomarkers, Tumor↗

PubMedDate not supplied

GRAFT infection of thoracic aorta due to group C beta-hemolytic streptococcus--a case report.

A fatal case of late-onset graft infection of the thoracic aorta due to group C beta-hemolytic streptococcus is described. A 37-year-old male patient, who had a history of total aortic arch replacement for acute aortic dissection 8 years before, was admitted to the department. He suffered from toxic shock syndrome, disseminated intravascular coagulation (DIC), and acute renal failure. Group C beta-hemolytic streptococcus was detected from his blood; however, echocardiography, computed tomography (CT), and magnetic resonance imaging (MRI) failed to detect the focus of the infection. In spite of intensive care, including antibiotic therapy, artificial ventilation, and continuous hemodiafiltration, he died on the 18th day of hospitalization. Autopsy revealed that a small abscess was present at the proximal anastomotic segments of the patient's graft. A bite inflicted by his dog, 14 days before admission, was suspected to be the source of this bacterium. A rare case of graft infection of thoracic aorta in terms of causative organism, long period from graft replacement to graft infection, and site of infection is presented and discussed.

Abscess↗

PubMedDate not supplied

C-met and hepatocyte growth factor expression in combined hepatocellular and cholangiocarcinoma.

The membranous tyrosine kinase receptor c-met and its natural ligand hepatocyte growth factor are prominent mitogens, motogens and morphogens for hepatocytes and many other cell types in vitro as well as in vivo. To clarify the significance of the c-met/hepatocyte growth factor system in the development and spread of combined hepatocellular and cholangiocarcinoma, surgical specimen from 30 patients, consisting of 4 double cancers, 20 combined types and 6 mixed types, were examined immunohistochemically. Immunoreactivity for HGF was significantly correlated with the differentiation degree of cholangiocellular components, being highest in well and moderately differentiated and lowest in poorly differentiated components (p=0.0119). No significant association was observed between expression of c-met or HGF and the presence of liver cirrhosis, vascular invasion, perineural invasion, lymphatic permeation, intrahepatic metastasis or lymph node metastasis. HGF may have an important impact on the differentiation of certain cHCC-CC. Other clinicopathologic factors related to tumor development and spread may not be influenced by c-met or HGF, at least not on the protein level.

Adult↗

PubMedDate not supplied

Overexpression of p53 protein and point mutation of K-ras genes in primary carcinoma of the small intestine.

Primary carcinoma of the small intestine is rare and represent about 0.5% of all gastrointestinal malignancies. The aim of this study was to examine the biological characteristics of primary carcinoma of the small intestine by immunohistochemical and nested polymerase chain reaction methods. Thirty-five primary carcinomas (12 in the duodenum and 23 in the jejunum or ileum) from 35 patients were studied clinicopathologically and examined for overexpression of p53 protein. In 22 of these 35 cases, point mutation at codon 12 of the K-ras gene was detected by the nested polymerase chain reaction and restriction fragment length polymorphism method. All the duodenal carcinomas were well-differentiated type and the rate of these carcinomas was significantly higher than that of jejunal or ileal carcinomas (100% vs. 65%). Fourteen cases showed overexpression of p53 (40%), and p53 tended to be expressed more frequently in poorly-differentiated type (71%) compared to well-differentiated type (30%). Only 2 out of 22 carcinoma cases showed K-ras gene mutation, and both were duodenal carcinomas. These findings suggest that p53 plays a major role in the progression of carcinoma of the small intestine, whereas the role of K-ras mutation is much less significant.

Adenocarcinoma↗

PubMedDate not supplied

Morphologic approach to hepatocellular carcinoma development in man: de novo or the so-called 'dysplastic nodule-carcinoma' sequence?

The so-called dysplastic nodule-carcinoma sequence in the liver is generally accepted because hepatocellular carcinoma is not an uncommon finding in precancerous lesions. In order to evaluate the existence and frequency of de novo hepatocarcinogenesis we studied 112 surgically resected early well-differentiated hepatocellular carcinomas showing replacing growth without less differentiated component in themselves. They were divided into two groups: carcinoma in dysplastic area (type A) and carcinoma without dysplastic area (type B) and were analyzed clinicopathologically. We encountered 77 cases of type A (68.8%) and 35 of type B (31.2%). The frequency of type A in cirrhotic group (74.7%) is statistically higher than that of non-cirrhotic group (54.5%) (p=0.0453). Using multivariate analysis, the occurrence of type A was related with higher age, the presence of cirrhosis and hepatitis B surface antigen positive. The tumor size and the presence of fatty change in the tumor tended to relate with type A. We propose two pathways morphologically in early hepatocarcinogenesis, one of which has a close relation to hepatitis B virus and/or cirrhosis.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Mucinous cystic tumor of the pancreas: immunohistochemical assessment of "ovarian-type stroma".

The new histopathological classification of exocrine pancreatic tumors by the World Health Organization, now includes "ovarian-type stroma" ("OS") in the definition of mucinous cystic tumor of the pancreas (MCT-P). This study investigated the clinicopathological findings of the MCT-P according to WHO classification and scrutinize the function of "OS" in MCT-P immunohistochemically. Thirty-four cases of MCT-P (28 adenomas, 2 borderline tumors and 4 adenocarcinomas) were examined clinicopathologically. The "OS" of 34 MCTs-P were studied immunohistochemically and compared with the stroma of 10 mucinous cystic tumors of the ovary (MCTs-O), 10 conventional pancreatic carcinomas and 6 normal ovaries. Almost all 34 MCTs-P were located in the body-tail of the pancreas of middle-aged women. Histologically the "OS" cells exhibited luteinization in 11/34 (32.4%). Immunohistochemically, both "OS" cells and the stromal cells in MCT-O showed similar positivity rates; calponin (34/34 and 9/10), h-caldesmon (28/34 and 8/10), alpha-inhibin (29/34 and 9/10), estrogen-receptor (21/34 and 6/10) and progesterone-receptor (28/34 and 9/10, respectively). Some neoplastic epithelial cells of MCT-P were positive for human chorionic gonadotropin (hCG) (21/34, 61.8%). This study indicates the predominance of MCT in the distal pancreas of middle-aged women. Furthermore, the immunohistochemical and histological results demonstrate that the "OS" of MCT-P and the stroma of MCT-O share the same characteristics. The results also suggested that the hCG produced by the neoplastic epithelium probably plays an important role in the luteinization of the stroma of MCT-P. We therefore conclude there is a possibility that MCT-P originates from the left remnant primordial gonadal cells which migrated to the pancreatic anlage during the early development of the fetus.

Adenocarcinoma, Mucinous↗