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Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant tumor syndrome. This hereditary cancer is caused by germline variants in MEN1. Two patients with MEN1 were identified via whole exome sequencing and gene expression profile analysis, conducted for 5,063 patients with various types of cancers. We obtained multiple tumors from each patient; tumors derived from these two MEN1 patients had a loss of the normal MEN1 allele and frequently chromosomal copy number changes. Thus, we investigated whether structural variants were present in the MEN1 patient genomes. Whole-genome sequencing revealed no catastrophic rearrangements, and the tumor samples had very low somatic variants. The two patients had germline variants in MEN1 and some chromosomal copy number changes including on chromosome 11. The only pathogenic variant detected was the MEN1 germline variant, and chromosomal rearrangements led to tumorigenesis in somatic cells. Furthermore, the MEN1 tumor samples displayed a specific signature characterized by T:A>C:G transition. Studies of multiple tumors obtained from single patients are rare in hereditary cancer syndromes, and our results provide insights that the second hit of the tumor suppressor gene MEN1 may be caused by a gross genome rearrangement, not a small insertion and deletion, nor a change in epigenetic regulation.

The accuracy and reproducibility of the World Health Organization (WHO) 2015 classification of bronchopulmonary neuroendocrine neoplasms (BP-NENs) is disputed. The aim of this study is to classify and grade BP-NENs using the WHO 2019 classification of digestive system NENs (DiS-NEN-WHO 2019), and to analyze its accuracy and prognostic impact. Two BP-NEN cohorts from Japan and Germany, 393 tumors (88% surgically resected), were reviewed and the clinicopathological data of the resected tumors (n = 301) correlated to patients’ disease-free survival (DFS). The DiS-NEN-WHO 2019 stratified the 350 tumors into 91 (26%) neuroendocrine tumors (NET) G1, 52 (15%) NET G2, 15 (4%) NET G3, and 192 (55%) neuroendocrine carcinomas (NEC). NECs, but not NETs, were immunohistochemically characterized by abnormal p53 (100%) and retinoblastoma 1 (83%) expression. The Ki67 index, which was on average 4 times higher than mitotic count (p < 0.0001), was prognostically more accurate than the mitotic count. NET G3 patients had a worse outcome than NET G1 (p < 0.01) and NET G2 patients (p = 0.02), respectively. No prognostic difference was detected between NET G3 and NEC patients after 5 year DFS. It is concluded that stratifying BP-NEN patients according to the DiS-NEN-WHO 2019 classification results in 3 prognostically well-defined NET groups, if grading is solely based on Ki67 index. Mitotic count alone may underestimate malignant potential of NETs.

The clinicopathological features of lung neuroendocrine neoplasms (NEN) with a high proliferative index at the border area between atypical carcinoid and neuroendocrine carcinoma have not been investigated so far. The aim of this study was, therefore, to search for lung NENs which are well differentiated but show Ki67 values that overlap with those of poorly differentiated (PD)-NENs. Resected lung NENs from 244 Japanese patients were reviewed, and Ki67 indices were assessed in all tumors. The data were then correlated to clinicopathological parameters and patient outcome. Among 59 (24%) well-differentiated (WD)-NENs and 185 (76%) lung PD-NENs, 7 were defined as WD-NENs with Ki67 indices > 20%. The Ki67 indices of these tumors (mean 29%, range 24–36) were significantly lower than those of PD-NENs (mean 74%, range 34–99). All WD-NENs with Ki67 > 20% lacked abnormal p53 and loss of retinoblastoma 1 (Rb1) expression. In contrast, many PD-NENs expressed p53 (48%) and showed loss of Rb1 (86%). The 2- and 5-year disease-free survival rates in WD-NEN patients with Ki67 > 20% were lower than those of WD-NEN patients with Ki67 ≤20% (p < 0.01 for disease-free and overall survival). No statistical differences were detected between outcome of WD-NEN patients with Ki67 > 20% and those of PD-NEN. It is concluded that WD-NEN patients with Ki67 > 20% share the morphological and immunohistochemical features of WD-NEN patients with Ki67 ≤20%, but they have a worse prognosis, suggesting that this tumor group requires particular attention in future classifications and probably new therapeutic regimes.

A cell fine of human medullary carcinoma of the thyroid, abundantly producing calcitonin (Ct) and related hormones, has proved remarkably useful as an endocrine tumor model for the study of the secretion mechanism. This cell line (TT cell) was used in studies to elucidate the dynamics of the release of Ct and chromogranin (Cg) to culture medium. The studies evaluated the intracellular concentration of Ct and Cg and the concentration changes elicited by the protein kinase C activator, phorbol ester (TPA); the adenylate cyclase-associated protein kinase A activator, forskolin; and the calcium ionophore, A23187. In addition, immunogold labeling of Ct and Cg was carried out to investigate the ultrastructural changes resulting from the stimulations. All these secretagogues effected the release of Ct and Cg into the medium in a dose-dependent manner, and the rate of the increase in the Ct secretion was consistently and markedly higher than that of Cg in more than certain dosages of the secretagogues. Most cells contained secretory granules immunolabeled for both Ct and Cg, and a considerable decrease was noted in the poststimulation count of the granules containing both substances, with the cells retaining more Cg than Ct. The discordance may be explained by different secretory pathways of the two proteins or different rates of synthesis.

BackgroundMultiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant tumor syndrome with neuroendocrine tumorigenesis of the parathyroid and pituitary glands and pancreatic islet cells. This hereditary cancer is caused by germline mutations in the MEN1, located on chromosome 11q13. Among the approximately 3,000 cancer patients, in which multi-omics analysis was performed, we had a patient with multiple tumors including pancreatic neuroendocrine tumor, thymic carcinoid and adenoma parathyroid, who showed no family history of MEN1.MethodsWe performed whole genome sequencing (WGS) of peripheral blood samples and three isolated tumor tissues (pancreas, thymus, and parathyroid). Sanger sequencing was used to validate MEN1 mutations; meanwhile, MEN1 mRNA levels on tumor samples were obtained by microarrays. MEN1 copy numbers and protein expression levels were determined by real-time PCR, and immunohistochemistry, respectively.ResultsMEN1 mRNA levels of pancreas and parathyroid tissues from patient-derived tumor samples were remarkably reduced, compared to those of 3,095 tumor and normal tissue samples. WGS data indicated the thymus sample with MEN1 nonsense mutation (W203*), while no MEN1 mutations were observed in the other two samples. WGS also identified MEN1 gross deletion of 18.5 kbp (chr11:64569322 – chr11:64587796; GRCh37/hg19 assembly) in peripheral blood samples and all the three tumor tissues. In addition, no MEN1 copy numbers on pancreas and parathyroid tumors were detected, whereas peripheral blood and the thymic carcinoid had one copy. Immunostaining of all the tissues detected very low levels of the MEN1 protein, Menin.ConclusionWe detected a hemizygous MEN1 germline deletion in blood sample of the MEN1 proband. All the three tumor samples had second hit with a deleterious mutation or normal alleles lacked to generate loss of heterozygosity at the MEN1 locus, suggesting loss of tumor suppressive function for MEN1.

In the light of novel cancer immune therapies, the status of antitumor inflammatory response and its regulation has gained much attention in patients with lung cancer. Ample datasets exist for non-small-cell lung cancer, but those for pulmonary neuroendocrine tumors are scarce and controversial. Here, tumor-associated inflammation, CD8+ cell infiltration and PD-L1 status were evaluated in a cohort of 57 resected carcinoids and 185 resected neuroendocrine carcinomas of the lung (58 large cell carcinomas and 127 small cell carcinomas). Data were correlated with clinicopathological factors and survival. Moderate or high tumor-associated inflammation was detected in 4 carcinoids (7%) and in 37 neuroendocrine carcinomas (20%). PD-L1 immunoreactivity was seen in immune cells of 73 (39%) neuroendocrine carcinomas, while tumor cells were labeled in 21 (11%) cases. Inflammatory cells and tumor cells in carcinoids lacked any PD-L1 expression. In neuroendocrine carcinomas, PD-L1 positivity in immune cells, but not in tumor cells, was associated with intratumoral CD8+ cell infiltration (P P P P

Objective High-grade neuroendocrine carcinoma of uterine cervix (HGNCUC) has been recognized as a highly malignant tumor. Therapeutic strategy specific to neuroendocrine (NE) tumors needs to be considered, but some cases wouldn't allow simple final diagnoses. Insulinoma-associated protein 1 (INSM1), which is a zinc-finger transcription factor related to NE differentiation, is frequently expressed in NE tumors. We investigated the association between INSM1 and HGNCUC, and the possibility of INSM1 as a useful NE marker. Methods Thirty-seven cases of formalin-fixed and paraffin-embedded HGNCUCs were evaluated immunohistochemically for conventional NE markers and INSM1. We also surveyed polymerase chain reactions and examined the frequency and the genotype of human papillomavirus (HPV) infections. Results In HGNCUC, chromogranin A, synaptophysin and neural cell adhesion molecule (NCAM) were expressed in 86%, 86% and 68%, respectively. In addition, INSM1 was detected in 95%. Positivity for INSM1 was clearly evaluated histologically, because the intensity of nuclear staining on positive cells was high and nonspecific reactions were minimal. In uni- and multivariate analyses of prognostic factors on stage I and II surgical cases, the association between INSM1 expression and prognosis was insignificant. We confirmed 72% of 29 examined cases had high risk HPV infections (type 16, 14%; type 18, 86%). Conclusions This study has clarified that INSM1 is closely related to the development of HGNCUC, and a useful new NE marker in conducting its correct and rapid diagnosis.

The clinicopathological features of lung neuroendocrine neoplasms (NEN) with a high proliferative index at the border area between atypical carcinoid and neuroendocrine carcinoma have not been investigated so far. The aim of this study was, therefore, to search for lung NENs which are well differentiated but show Ki67 values that overlap with those of poorly differentiated (PD)-NENs. Resected lung NENs from 244 Japanese patients were reviewed, and Ki67 indices were assessed in all tumors. The data were then correlated to clinicopathological parameters and patient outcome. Among 59 (24%) well-differentiated (WD)-NENs and 185 (76%) lung PD-NENs, 7 were defined as WD-NENs with Ki67 indices20%. The Ki67 indices of these tumors (mean 29%, range 24-36) were significantly lower than those of PD-NENs (mean 74%, range 34-99). All WD-NENs with Ki6720% lacked abnormal p53 and loss of retinoblastoma 1 (Rb1) expression. In contrast, many PD-NENs expressed p53 (48%) and showed loss of Rb1 (86%). The 2- and 5-year disease-free survival rates in WD-NEN patients with Ki6720% were lower than those of WD-NEN patients with Ki67 ≤20% (p0.01 for disease-free and overall survival). No statistical differences were detected between outcome of WD-NEN patients with Ki6720% and those of PD-NEN. It is concluded that WD-NEN patients with Ki6720% share the morphological and immunohistochemical features of WD-NEN patients with Ki67 ≤20%, but they have a worse prognosis, suggesting that this tumor group requires particular attention in future classifications and probably new therapeutic regimes.

Introduction During surgical resection of a peripherally located high-grade neuroendocrine carcinoma (HGNEC), we unexpectedly discovered prominent bronchial intraepithelial tumor spread up to the surgical end of the bronchus. Because bronchial intraepithelial tumor spread of peripherally located HGNEC has been rarely reported, we conducted a retrospective analysis at our hospital. Methods We histologically reviewed surgically resected HGNEC cases to assess bronchial intraepithelial spread of tumor cells. HGNECs with bronchial intraepithelial tumor spread were further studied by immunohistochemistry for neuroendocrine markers, and their clinicopathological characteristics were evaluated. Results Of 1778 cases of surgically resected lung cancer in our hospital, 47 cases of HGNEC were evaluated. Bronchial intraepithelial tumor spread was observed in nine cases (19.1%); eight of these cases were large-cell neuroendocrine carcinoma (LCNEC) or small-cell lung carcinoma with an LCNEC component. Moreover, bronchial intraepithelial tumor spread was continuous from the primary tumor to the resected end of the bronchus in four cases, and all these cases had an LCNEC component. Furthermore, HGNEC with bronchial intraepithelial tumor spread was associated with a higher recurrence rate than no bronchial intraepithelial tumor spread. Conclusion The results of this study suggest that bronchial intraepithelial tumor spread is commonly observed in cases of peripherally located HGNEC and may be a unique form of tumor invasion, especially tumors with LCNEC morphology. Therefore, surgeons and pathologists should be cognizant of bronchial intraepithelial tumor spread in peripherally located HGNEC, as well as its potential role as an indicator of HGNEC aggressiveness.

Background The pathological criteria of early-stage mucinous adenocarcinoma of the lung have recently been defined; however, its characteristic radiologic imaging findings are still poorly understood. Thus, this study aimed to clarify the radiologic and pathological findings of early-stage mucinous adenocarcinoma. Materials and methods In this study, we clinicopathologically reviewed 22 cases of surgically resected mucinous adenocarcinoma in situ (AIS) and minimal invasive adenocarcinoma (MIA), and attempted to elucidate the characteristic radiologic features of early mucinous adenocarcinomas using high-resolution computed tomography (HRCT). Results Radiologically, the mean value of the maximum diameter of 22 tumours was 2.1 cm (range, 1.0–2.9 cm). Based on the HRCT findings, the tumours were divided into part-solid ground glass nodules (n = 11) and solid nodules (n = 11). The mean CT attenuation value was 25.7 HU (range, 17–35 HU). All tumours, except 3 tumours pathologically diagnosed as AIS, showed air-containing features. According to the preoperative CT findings, 7 (35%) cases were diagnosed as inflammatory nodules. Of these, 4 cases had lobular-bounded margins, and 3 showed vaguely outlined ground glass shadows. Conclusion The characteristic HRCT findings of mucinous AIS and MIA were solid or part-solid nodules with air-containing spaces. However, some AIS and MIA nodules showed lobular-bounded margins or marginally vaguely outlined ground glass shadows, and were difficult to differentiate from inflammatory nodules.

We analyzed serum ProGRP levels in patients with Ewing sarcoma, and found that 5 out of 9 patients had elevated levels; the values range equally with those of patients with limited disease of small-cell lung carcinoma. Serum ProGRP levels in patients with bone and soft tissue malignancies other than Ewing sarcoma are not elevated. Immunohistochemical studies demonstrated that ProGRP-like immunoreactivities were detected in Ewing sarcoma tissues obtained from 2 patients with elevated serum ProGRP levels, suggesting that ProGRP is a product of tumor cells of Ewing sarcoma. These results indicate that serum ProGRP could serve as a specific tumor marker for Ewing sarcoma. Since ProGRP is a major hormonal product of tumor cells of small-cell lung carcinoma, a typical neuroendocrine carcinoma, it is reasonable to postulate that the present study provides an evidence for Ewing sarcoma to possess neuroendocrine differentiation.

We report a case of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). We performed immunohistochemical analysis of 17 neuropeptides and human gonadotropin-alpha (hCGα), a trophoblastic peptide that promotes the proliferation of neuroendocrine cells. A 51-year-old woman with no history of smoking was found to have a nodule in the right middle lobe. Upon examination, the nodule was found to comprise diffuse linear and nodular neuroendocrine cell hyperplasia (NECH), numerous pulmonary tumorlets merging with one peripheral carcinoid, and an additional central carcinoid. Immunohistochemical analysis revealed diffuse but intense expression of the general neuroendocrine markers CD56, synaptophysin, and chromogranin A, together with gastrin-releasing peptide (GRP), calcitonin, and hCGα throughout the carcinoids, tumorlets, and NECH. Positive staining was also noted for adrenocorticotropic hormone, corticotropin-releasing hormone, met-enkephalin, vasoactive intestinal polypeptide, neurotensin, and growth hormone-releasing hormone in a few isolated cells of the carcinoids and the tumorlets, but staining for these proteins was entirely negative in the NECH lesions. The presence of these neuropeptides in neuroendocrine tumors might explain the presence of neuropeptide-producing tumors of the lungs, cases of which have been reported over the last 30 years. The preoperative serum proGRP level was high but returned to normal after surgical intervention, indicating that GRP was produced and secreted by carcinoids, tumorlets, and/or NECH lesions. It is also probable that neuroendocrine cells secreted GRP into the interstitium in a paracrine manner, leading to the development of dense fibrosis around the tumorlets. During the preoperative and postoperative periods, no evidence of bronchiolitis obliterans was noted, in contrast to some previously reported cases of DIPNECH.

Since the World Health Organization histological criteria were published in 1999, several studies have focused on adenosquamous carcinoma of the lung. Therefore, we aimed to clinicopathologically re-evaluate this tumor using immunohistochemical methods. In our hospital, there have been 21 surgically resected adenosquamous carcinomas. The frequency of adenosquamous carcinoma was 1.9% and the clinical data including the patient prognosis data obtained in this study were similar to those reported previously. A fluorodeoxyglucose positron emission tomography study first revealed that the median maximum standardized uptake value of adenosquamous carcinoma was 9.3 and ranged from 2.0 to 24.5. According to the results of immunohistochemical staining for thyroid transcription factor-1 (TTF-1) and p63, adenosquamous carcinomas were divided into four subgroups: group 1, TTF-1+ and p63+ (10 cases); group 2, TTF-1- and p63+ (six cases); group 3, TTF-1+ and p63- (three cases); and group 4, TTF-1- and p63- (two cases). Of the six group 2 tumors, three were composed of unique solid nests with mucin-filled cysts and showed characteristic p63 expression, which might suggest a special type of adenosquamous carcinoma. Immunohistochemical analysis of TTF-1 and p63 expression shows that adenosquamous carcinoma is composed of diverse tumor groups, for which the biological and histogenetic nature further needs to be clarified.

The earliest pathological events in the development of malignant pleural mesothelioma (MPM) are not understood. The aim of the present study was to elucidate the early histopathological features of MPM. A total of 16 extrapleural MPM pneumonectomy patients were investigated. Early stage mesothelioma was arbitrarily defined as a tumor < or =5 mm in thickness regardless of the nodal status or other organ involvement. Eight of these patients (six with epithelioid, two with biphasic) had early stage mesothelioma by this definition. Macroscopically there was no visible tumor, but the parietal and visceral pleura were thickened and there was focal adhesion between them. Microscopically, the mesothelioma lesions were multifocal and discontinuous on the pleura. In extremely early cases of epithelioid mesothelioma, tumor cells were generally arrayed in a single layer, but papillary proliferation was observed elsewhere. In sarcomatoid mesothelioma, mesothelioma cells proliferated, forming multiple small polypoid nodules on the pleura. Epithelial membrane antigen was helpful to distinguish reactive from neoplastic mesothelium, but glucose transporter-1 was not. Mesothelioma cells disseminate diffusely throughout the parietal and visceral pleura and mediastinal fat tissue before becoming visible. Stage Ia mesothelioma (neoplasm limited to the parietal pleura) would not be observed in daily practice.

A 75-year old man initially complained of pollakiuria and low abdomlnal pain, and died of massive bleeding from an exacerbated gastric ulcer. The dlagnosis of primary cardiac lymphoma was made postmortem. The tumor involved only the epicardium and myocardium, which met the criteria of primary cardiac lymphoma as defined by the Armed Forces Institute of Pathology. The lymphoma consisted of large cells and expressed the B cell marker, CD20. Although chronic inflammation due to chronic renal failure was observed in the pericardium around the lymphoma, polymerase chain reaction (PCR) was conducted to detect monoclonality at the DNA level in lymphoma cells, which were shown to comprise a monoclonal population. Acta Pathol Jpn 42: 667–671, 1992.

Matrix-producing carcinoma of the breast is a well-established entity in the group of metaplastic carcinoma, which is histologically characterized by myxochondroid matrix formation and is extremely rare. We describe here four additional cases of matrix-producing carcinoma of the breast. All cases of matrix-producing carcinoma show nest-like, sheet-like, and cord-like growth of tumor cells with cellular atypia, in addition to scattered cancer cells within myxoid or myxohyalinous stroma. Three of four cases showed an acellular or oligocellular matrix-rich zone in the center of the tumor. Immunohistochemically, cancer cells of all cases were positive for cytokeratins and epithelial membrane antigens and partially positive for sox9 and p63. Aggrecan and type II collagen, which are cartilage-specific matrix molecules, were deposited in the stroma of all cases. Type I and type IV collagens were also deposited on the stroma of all cases. These findings suggest that, although cancer cells of matrix-producing carcinoma of the breast are epithelial, they transdifferentiate to chondrocyte-like cells and produce cartilage-specific matrix molecules, which are useful markers for diagnosing matrix-producing carcinoma.

Alveolar soft part sarcoma (ASPS) is a rare mesenchymal neoplasm of uncertain origin. In this article, we report a case of ASPS occurring in the larynx, an extremely rare location for this rather unusual tumor.The patient was a 34-year-old Japanese woman who requested an examination for hoarseness. The tumor showed a proliferation of large polygonal cells with periodic-acid-Schiff-positive diastase-resistant intracytoplasmic granules, arranged in an alveolar growth pattern. The cytoplasm of the tumor cells was eosinophilic. Tumor cells were positive for vimentin and titin. Nuclear immunoreactivity for TFE3 was observed, and the Ki-67 labeling index was 14.7%. Ultrastructurally, electron-dense rod-shaped crystals were infrequently observed in the cytoplasm. This case was finally diagnosed as ASPS of the larynx.We discuss the histogenesis and differential diagnosis of ASPS with immunohistochemical and ultrastructural findings. TFE3 immunohistochemistry was found to be a very useful marker for the diagnosis of ASPS.

Dedifferentiation of salivary gland neoplasms is a rare event, unlike bone and soft part sarcomas, which was first described by Stanley et al. in 1988. An additional case of dedifferentiated epithelial-myoepithelial carcinoma (EMC) is reported here. The patient was a 70-year-old Japanese man who requested examination of the rapid growth of a mass in the right parotid region, which he had first noticed 25 years previously. Clinical examination showed an ill-circumscribed, 6.8 x 4.7 x 7.0-cm lesion. Histologically, most parts of the lesion were high-grade carcinoma (HGC) with sheetlike and nestlike growth of markedly atypical cells and comedonecrosis, whereas the minor part consisted of typical EMC. The outer clear cells of EMC were positive for alpha-smooth muscle actin (ASMA), p63, cytokeratin (CK) 14, and vimentin, and the inner ductal cells of EMC were positive for CKs and epithelial membrane antigen. HGC was negative for ASMA, CK14, and vimentin, but diffusely positive for p53 protein and cyclin D1. The Ki-67 labeling index of EMC was 11.5%, whereas that of HGC was 67.1%. These findings and a review of literature indicate that HGC arose from preexisting EMC, and this phenomenon is the dedifferentiation of EMC. Dedifferentiated EMC is extremely rare.

During surgical resection of a peripherally located high-grade neuroendocrine carcinoma (HGNEC), we unexpectedly discovered prominent bronchial intraepithelial tumor spread up to the surgical end of the bronchus. Because bronchial intraepithelial tumor spread of peripherally located HGNEC has been rarely reported, we conducted a retrospective analysis at our hospital.We histologically reviewed surgically resected HGNEC cases to assess bronchial intraepithelial spread of tumor cells. HGNECs with bronchial intraepithelial tumor spread were further studied by immunohistochemistry for neuroendocrine markers, and their clinicopathological characteristics were evaluated.Of 1778 cases of surgically resected lung cancer in our hospital, 47 cases of HGNEC were evaluated. Bronchial intraepithelial tumor spread was observed in nine cases (19.1%); eight of these cases were large-cell neuroendocrine carcinoma (LCNEC) or small-cell lung carcinoma with an LCNEC component. Moreover, bronchial intraepithelial tumor spread was continuous from the primary tumor to the resected end of the bronchus in four cases, and all these cases had an LCNEC component. Furthermore, HGNEC with bronchial intraepithelial tumor spread was associated with a higher recurrence rate than no bronchial intraepithelial tumor spread.The results of this study suggest that bronchial intraepithelial tumor spread is commonly observed in cases of peripherally located HGNEC and may be a unique form of tumor invasion, especially tumors with LCNEC morphology. Therefore, surgeons and pathologists should be cognizant of bronchial intraepithelial tumor spread in peripherally located HGNEC, as well as its potential role as an indicator of HGNEC aggressiveness.

Mucoepidermoid carcinoma is a common neoplasm of the salivary glands. Salivary gland-type neoplasms are very rare in the nasopharynx, and there are only few reports on mucoepidermoid carcinoma of the nasopharynx. Two additional cases of mucoepidermoid carcinoma arising from the nasopharynx are reported here. Case 1: the patient was a 57-year-old Japanese woman who had bloody sputum. Case 2: the patient was a 51-year-old Japanese woman who underwent resection of a nasopharyngeal tumor. Histologically, both tumors were also low-grade mucoepidermoid carcinomas with clear cells. Histochemically, the gland-like nests and mucous cells were positive for mucin staining. Immunohistochemically, the lesions were positive for cytokeratins (CKs), p63, and MUC1, but negative for alpha-smooth muscle actin and EBER mRNA. The Ki-67 labeling indices of the two tumors were 10.4% and 4.3%, respectively. The two present cases and a review of the English literature indicate that salivary gland-type neoplasms arising from the nasopahrynx are extremely rare. The prognosis of salivary gland-type carcinomas of the nasopharynx is still unknown.

Background: Telomeres are important for chromosome structure and function, protecting them against degradation. However, few studies have examined telomeres in pulmonary neuroendocrine (NE) tumors. Methods: We investigated deparaffinized sections obtained from 70 primary NE lung tumors [34 typical carcinoids (TCs), 10 atypical carcinoids (ACs), 16 large cell neuroendocrine carcinoma (LCNECs) and 10 small cell lung carcinomas (SCLCs)]. Results: Positive expressions of human telomerase mRNA component (hTERC) and human telomerase reverse transcriptase (hTERT) mRNA were recognized, respectively, in 58% and 74% of TCs, and in 100% and 100% of ACs, LCNECs and SCLCs. Alteration of telomere length was greater in both LCNECs and SCLCs than in TCs. Telomerase activity was detected in LCNECs, but not in TCs. By the reverse-transcriptase polymerase chain reaction (RT-PCR), hTERC mRNA was detected in 100% of LCNECs and TCs examined, while hTERT mRNA was detected in 67% of LCNECs, but not at all in TCs. Conclusions: These results suggest that alterations in telomere length, telomerase activity, and the expression of hTERT mRNA may (i) play roles in pathogenesis in pulmonary neuroendocrine tumors, and (ii) be a useful tool for differential diagnosis between TCs and LCNECs.

Background: Radicular cysts are the most common cysts in human jaw bones. These lesions induce bone remodeling of the surrounding alveolar bones, which was termed ‘condensing osteitis’, and was suggested to be related to cells of the osteoblastic lineage. The Runx2 (core-binding protein [cbfa]1/polyoma enhancer-binding protein [pebp]2αA) was shown to be a DNA-binding transcriptional molecule expressed in osteoprogenitor cells. Methods: We confirmed the specificity of anti-Runx2 antiserum, using Western blotting analysis. We investigated the expression and localization of Runx2 in 32 radicular cyst cases with bone tissue fragments, immunohistochemically. Results: Signals for Runx2 were seen in 18 cases (56.3%) of radicular cysts with bone formation. These signals were immunolocalized in the nuclei of the spindle-shaped osteoprogenitor cells in the cyst walls, whereas only a few signals were seen in the cuboidal osteoblastic cells near the fibrous bones. Signals for type I collagen were immunolocalized in the dense collagen fibers in the cyst walls and in the matrix of the fibrous bone around the radicular cysts, whereas no signals were seen on the inner portions with inflammatory cell infiltration of the cyst walls. Very weak signals for transforming growth factor (TGF)-β1 were infrequently seen in the osteoblasts of the fibrous bone, whereas signals for TGF-β2 were observed in young osteocytes in the fibrous bones, in B-cell lymphocytes infiltrating into the inner portions, and on the cellular membranes of the lining epithelium. Conclusions: The nuclear expression of Runx2 in spindle-shaped cells in the outer portions may play an essential role in the induction of fibrous bone tissue around radicular cysts. TGF-β2 may play a role in the production of type I collagen, which acts as a template for pathologic new bone formation, in radicular cysts.

The current histologic classifications of gastric cancers define only carcinoids and small cell carcinomas in the neuroendocrine (NE) category. This study aimed to characterize the histologic and clinical features of high-grade gastric NE carcinomas of nonsmall cell type, tentatively named large cell neuroendocrine carcinoma (LCNEC). Tumors with histologic features suspicious of NE differentiation were selected by a histologic review of 2835 resected gastric cancers, and those with a NE phenotype in50% and 1% to approximately 50% tumor cells assessed by expressing chromogranin A and/or synaptophysin were defined as LCNEC and adenocarcinoma with neuroendocrine differentiation (ACNED), respectively. One hundred ninety-nine tumors were selected and of the 109 positive for chromogranin A and/or synaptophysin, 42 and 44 met the criteria for LCNEC and ACNED, respectively. Generally, LCNECs demonstrated less predominant NE morphology than carcinoids, and could be roughly divided into solid (30 cases), tubular (7 cases), and scirrhous (5 cases) subtypes with reference to their main growth pattern. The prognosis of LCNECs was significantly worse than that of conventional adenocarcinomas (P0.0001). Thus, this study shows that the spectrum of gastric NE tumors is broader than has previously been recognized and LCNEC is not only a distinct histopathologic entity, but also a distinct clinical entity. Furthermore, the prognosis of ACNEDs was also significantly worse than that of adenocarcinomas (P0.0001), and some ACNEDs might actually have been LCNECs, and survival analysis showed that20% positivity of NE markers could be enough to characterize LCNEC, as long as light microscopic NE morphology was present in the tumor.

Purpose Neuroendocrine (NE) tumors of the lung include typical carcinoid (TC), atypical carcinoid (AC), large-cell NE carcinoma (LCNEC), and small-cell lung carcinoma (SCLC). Their clinicopathologic profiles and relative grade of malignancy have not been defined. Patients and Methods From 10 Japanese institutes, 383 surgically resected pulmonary NE tumors were collected. The histologic diagnosis was determined by the consensus of a pathology panel consisting of six expert pathologists as TC, AC, LCNEC, or SCLC on the basis of the WHO classification, and its relationship to clinicopathologic profiles was analyzed. Results Of the 383 tumors, 18 were excluded because of an improper specimen. The pathology panel reviewed the remaining 366 tumors, and a diagnosis of NE tumor was made in 318 patients (87.4%); 55 patients had TC, nine had AC, 141 had LCNEC, and 113 had SCLC. The 5-year survival rates of patients with all stages were as follows: 96.2% for TC, 77.8% for AC, 40.3% for LCNEC, and 35.7% for SCLC. There was significant prognostic difference between TC and AC as well as between AC and LCNEC+SCLC. However, there was no difference between LCNEC and SCLC, and their survival curves were superimposed. The multivariate analysis indicated that histologic type, completeness of resection, symptoms, nodal involvement, and age were significantly prognostic. Conclusion The grade of malignancy of NE tumors was upgraded in the following order: TC, AC, LCNEC, and SCLC. No prognostic difference was noted between LCNEC and SCLC. The high-grade NE histology uniformly indicated poor prognosis regardless of its histologic type.

Pituicytoma is a rare tumor in the sellar or suprasellar region with distinct histological characteristics of glial neoplasm. A 42-year-old woman presented with a history of amenorrhea and vertigo, and a 62-year-old woman presented with mild headache. Both patients had mild hyperprolactinemia and one had mild anterior pituitary dysfunction. They underwent transcranial partial resection of a suprasellar tumor. The tumors were characterized by storiform pattern of elongated cells immunoreactive for S-100 protein and glial fibrillary acidic protein. Ultrastructural study showed abundant cytoplasmic intermediate filaments and tumor/blood vessel basal lamina, but no desmosomes between tumor cells. The residual tumors showed no changes in size without adjuvant therapy at 56 and 18 months after surgery. Pituicytoma is a glial neoplasm of adults with low proliferative activity. Patients often present with visual symptoms or anterior pituitary dysfunction. Symptoms and signs of neurohypophysis are rare. Neuroimaging reveals an intra- or suprasellar mass with non-specific features. The prognosis and role of adjuvant therapy remain unclear for this discrete noninfiltrative glioma.

E-cadherin, which expressed in various epithelial tissues, is important for the maintenance of normal epithelial phenotypes. However, the distribution of N-cadherin in normal human tissues has not been defined systemically. In the present study, we employed a sensitive, reliable immunohistochemical detection system for N-cadherin on formalin-fixed, paraffin-embedded tissue sections, and succeeded in demonstrating N- and E-cadherin protein expressions and their distribution in normal human tissues. E-cadherin immunoreactivity was detected in all the epithelial tissues examined, except for the adrenal cortical cells and granulosa cells. N-cadherin was selectively expressed on epithelial cells of the thymus, pituitary, pancreas, liver, adrenal, endometrium of the uterus, ovary, and stomach as well as in neuronal tissues. Double immunostaining revealed that N-cadherin expression was closely associated with the hormone-producing ability of cells in the pancreas and pituitary. Thus, this study indicated the possibility that N-cadherin is selectively expressed in relation to hormonal regulation in some organs and plays different functions in different situations. The method presented here should prove useful for the further investigation of the N-cadherin expression and function in several disease conditions on formalin-fixed, paraffin-embedded archival tissues.

The rdw rat was initially reported as having hereditary dwarfism caused by pituitary dysfunction. Subsequent studies on the rdw rat, however, have demonstrated that the primary cause of rdw dwarfism is present in the thyroid gland but not in the pituitary gland. The primary cause of rdw rat disorders is a missense mutation of the thyroglobulin (Tg) gene by a one-point mutation. In the present study, we attempted to rescue the dwarfism of the rdw rats using a diet supplemented with thyroid powder (T-powder) and a thyroid graft (T-graft). The infants of the rdw rat were successfully raised to a mature stage body weight, accompanied by elevation of serum growth hormone (GH) and prolactin (PRL), by the T-powder. Furthermore, the T-graft successfully increased the body weight with fertility. The serum GH and PRL levels in the T-graft rdw rat significantly increased. The serum thyroid-stimulating hormone (TSH) levels in the T-graft rdw rat were significantly decreased but were significantly higher than those in the control rat. The GH and PRL mRNA expression in the rdw rat with the T-graft was virtually the same as that of the control, but the TSH beta mRNA differed from that of the control rats. Thus, the dwarfism in the rdw rat is rescued by thyroid function compensation, such as that afforded by T-powder and T-graft.

We report an 80-year-old man who presented with non-islet cell tumor hypoglycemia (NICTH) in association with hepatic recurrence of gastric cancer. His serum potassium was reduced from 3.9 to 3.1 mmol/l 5 weeks after gastrectomy, and he subsequently developed hypoglycemic coma. He was diagnosed as having NICTH because of the presence of serum big IGF-II and positive staining for IGF-II in gastric cancer cells obtained at surgery. A computed tomography showed multiple liver metastases. His hypoglycemia was refractory to steroid therapy. This case suggested that NICTH could develop in association with hepatic metastases of gastric cancer. Unexpected hypokalemia may be a manifestation of occult NICTH.

Extraskeletal myxoid chondrosarcoma is a rare soft tissue sarcoma of uncertain histogenetic origin. Because recent reports have indicated neural-neuroendocrine differentiation in some extraskeletal myxoid chondrosarcomas, we investigated 25 tumors for expressions of microtubule-associated protein-2 and Class III beta-tubulin, which are major components of microtubules and specifically localized in neurons and their derivatives. Immunohistochemical expression of microtubule-associated protein-2 and Class III beta-tubulin was studied in extraskeletal myxoid chondrosarcomas using formalin-fixed, paraffin-embedded tissues. Cytoplasmic expressions of microtubule-associated protein-2 and Class III beta-tubulin were detected in 21 (84%) and 13 (52%) of the 25 extraskeletal myxoid chondrosarcomas, respectively, although the number of positively stained tumor cells varied. Expression of the Class III beta-tubulin gene was also assessed in two immunohistochemically positive cases by in situ hybridization using an oligonucleotide probe specific for its transcript, and both cases showed expression of Class III beta-tubulin transcript. Another case was examined with immunoelectron microscopy, and immunogold particles for Class III beta-tubulin were localized to microtubular aggregates. Our data indicate that microtubules in extraskeletal myxoid chondrosarcoma are similar to those found in neurons, further supporting the concept that neural-neuroendocrine differentiation occurs in a significant number of extraskeletal myxoid chondrosarcoma.

Purpose: Cyclin A is known as an S- and G2-M phase regulatory protein and its abnormal expression has been reportedly implicated in cellular proliferation. This study was designed to investigate the correlation of cyclin A expression with tumorigenesis of the endometrium and clinicopathological variables. Methods: Immunohistochemical staining using labeled streptavidin-biotin complex was performed on formalin-fixed, paraffin-embedded tissue of normal endometrium (15 cases), endometrial hyperplasia (23 cases), and endometrial adenocarcinoma (endometrioid type) (112 cases). Results: Immunohistochemistry showed that the nuclei of the cells were positive for cyclin A. In normal endometrium, only proliferative phase was focally positive for cyclin A. Cyclin A was also positive for endometrial hyperplasia. Its expression in hyperplasia was significantly more frequent than that of proliferative phase and less than that of endometrioid adenocarcinoma. The labeling index (LI) of cyclin A in endometrioid adenocarcinoma was 16.3±6.9 in well-differentiated, 18.3±8.8 in moderately differentiated, and 30.2±11.8 in poorly differentiated adenocarcinoma, respectively. Cyclin A expression increased significantly more in high histological grades. The area of squamous metaplasia in endometrioid adenocarcinoma was negative for cyclin A. The LI of cyclin A was positively correlated with that of Ki-67 and cyclin-dependent kinase 2. Cyclin A expression was significantly associated with carcinoma without coexisting endometrial hyperplasia and lymphovascular space involvement (LVSI), but not with FIGO stage, myometrial invasion, lymph node metastasis, estrogen receptor, progesterone receptor, and menopause as well as recurrence. Conclusions: Cyclin A expression was involved in the progression to malignancy of the endometrium and was correlated with proliferative activity and prognostic features including histological grade, without coexisting endometrial hyperplasia and LVSI.

An examination was made of the incidence of the Epstein-Barr virus (EBV) genome and its exact localization in 39 cases of nasopharyngeal carcinoma (NPC) in Japanese patients by means of in situ hybridization (ISH) with a digoxigenin-labeled Epstein-Barr virus-encoded small nuclear RNA 1 (EBER1) oligonucleotide probe. Hybridization signals were observed in the nucleus of tumor cells in all 39 NPCs, including keratinizing carcinomas. The signals varied greatly in intensity from case to case and even from cell to cell in the same tumor, but were recognized in most tumor cells in each case. Signals could occasionally be seen in limiting number of infiltrating small lymphocytes but were absent in all tumors of the tongue, midpharynx and hypopharynx. Combined immunohistochemistry-ISH studies indicated that EBER1 signals were restricted to tumor cells positive for cytokeratin. As a result of this study, it is now possible to perform large-scale retrospective analyses using routine formalin-fixed, paraffin-embedded tissue sections and to combine ISH for the EBV genome with immunohistochemistry for cytokeratin to determine the epithelial features of EBV genome-possessing cells. All NPCs were clearly shown to be EBV-infected, thus indicating that EBV is essential for the oncogenesis of NPCs.

To obtain an adequate quality and quantity of DNA from formalin-fixed and paraffin-embedded tissue, six different DNA extraction methods were compared. Four methods used deparaffinization by xylene followed by proteinase K digestion and phenol-chloroform extraction. The temperature of the different steps was changed to obtain higher yields and improved quality of extracted DNA. The remaining two methods used microwave heating for deparaffinization. The best DNA extraction method consisted of deparaffinization by microwave irradiation, protein digestion with proteinase K at 48 degrees C overnight, and no further purification steps. By this method, the highest DNA yield was obtained and the amplification of a 989-base pair beta-globin gene fragment was achieved. Furthermore, DNA extracted by means of this procedure from five gastric carcinomas was successfully used for single strand conformation polymorphism and direct sequencing assays of the beta-catenin gene. Because the microwave-based DNA extraction method presented here is simple, has a lower contamination risk, and results in a higher yield of DNA compared with the ordinary organic chemical reagent-based extraction method, it is considered applicable to various clinical and basic fields.

Summary We examined the proliferative activity and the differentiation line of tumor cells in a case of “hyalinizing spindle cell tumor with giant rosettes” (HSCGR). A 6 cm tumor within the right deltoid muscle of a 58-year-old female was found by physical and radiographical examinations. A biopsy revealed the histological features of a spindle cell tumor with rosette-like structures. Wide excision was done under the diagnosis of HSCGR. The tumor presented as a gray-whitish, solid mass with focal pseudocystic degeneration. Immunohistochemically, the tumor cells were diffusely positive for vimentin and were also focally positive for S-100, but negative for desmin and α-smooth muscle actin. The cells stained positively for Ki-67 with even distribution, there being a correlation with the cellularity of the areas, with a labeling index ranging from 0.3 to 0.5%. In addition, flow cytometry revealed an almost normal diploid DNA pattern and 5.8% S-phase fraction, indicating low proliferative activity. Ultrastructurally, many tumor cells displayed discontinuous basal lamina, pinocytotic vesicles, dilated rough endoplasmic reticulum, and microfilaments with focal dense bodies. The main component of the rosette was collagenous fibrils with normal diameter and normal periodic banding. We interpreted this case of HSCGR as a low grade fibrosarcoma with remarkable differentiation of myofibroblastic lineage, and with focally accumulated, morphologically normal collagenous fibrils.

There has been accumulating histological observation of leiomyoma and leiomyosarcoma of the external soft tissue regarding their differential diagnosis. The definitive diagnostic tools have not been established, however, nor have the pathological mechanisms of cell proliferation in these tumors been clarified. Herein, expression of the cyclin-dependent kinase inhibitors (CKIs), p21, p27 and p57 and their associated kinase activities were examined in 61 cases of soft tissue smooth muscle tumors. Immunohistochemical staining showed that all 3 inhibitor proteins were expressed in all cases of leiomyoma and leiomyosarcoma, but that the mean values of their labeling indices (LIs) were higher in the cases of leiomyosarcoma. In addition, the LIs of p21 and p27 were inversely correlated in total cases. Immunoblotting revealed that these proteins are expressed at higher levels in tumors, in particular, in leiomyosarcoma. When CKIs were immunoprecipitated from tissue extracts, cyclin/cdk protein complexes associated with, at least, 1 CKI were detectable only in tumor tissues. Furthermore, cdk2 or cdk4 kinase activity manifested by these cyclin/cdk/CKI complexes (CKI-associated kinase activity) was detectable exclusively from leiomyosarcoma, but not from leiomyoma. Among the cases of leiomyosarcoma, cdk2 activity was generally found associated either with p21 or p27, but not both. Statistical analysis indicated that p21- and p27 LIs are predictive of positive or negative clinical outcome, respectively. In conclusion, the participation of CKIs in active cyclin/cdk complexes in a reciprocal and redundant manner and subsequent CKI- associated kinase activity are the characteristic profiles of malignant phenotype in these tumors. Moreover, immunohistochemical detection of CKIs may provide a useful tool for evaluating patients' prognosis. © 2001 Wiley-Liss, Inc.

Histological differentiation between benign and malignant adrenocortical tumors is currently based on the criteria of Weiss et al. (Weiss criteria) and vimentin immunostaining, but the prognostic values of the criteria in pediatric cases are still unclear. We analyzed the histological features, immunostaining status of p53, vimentin, Ki67 and cyclin-A, and clinical outcomes of four pediatric adrenocortical carcinomas diagnosed based on the Weiss criteria. One child developed metastases and recurrence, and died of the disease six months after tumor resection. The other three were disease free two to nine years after surgery. Tumor necrosis, and vascular and capsular invasion, three items of the Weiss criteria, and large tumor size seemed to be correlated with worse prognosis. On the other hand, mitotic count and atypical mitosis, two major factors of the Weiss criteria, and tumor proliferating fraction (TPF), as well as the immunostaining status of vimentin, seemed irrelevant to the clinical outcomes. In conclusion, some pediatric adrenocortical carcinomas diagnosed according to the Weiss criteria may behave benignly, and diagnostic criteria for pediatric adrenocortical tumors remain to be defined.

We describe a novel rapid double histochemical staining method for in situ hybridization (ISH) and immunohistochemistry (IHC) of formalin fixed, paraffin embedded tissue sections. For this purpose, 3 cases of Epstein-Barr virus (EBV) positive gastric carcinoma tissues and 5 cases each of pulmonary adenocarcinoma and squamous cell carcinoma tissues were used. The method employs the Micro Probe System, which is based on capillary action, to sequentially supply, incubate, and remove liquid reagents, including antibodies, probe solution, and substrates for histochemical staining of tissue sections. The method consists of ISH with EBV-encoded small RNA (EBER-1) or epidermal growth factor receptor (EGFR) for the first cycle, and IHC with anti-pan keratin antibody (AEl/AE3), anti-T cell (CD45R0, UCHL-1), or anti-B cell (CD20, L26) antibody or antibody to Ki-67 antigen for the second. To block cross reactivity, probes and protein reagents bound to tissue were removed by microwave oven heating with citrate...

Adenocarcinoma of the lung is a common malignancy. Frequently, this tumor can cause calcification within a primary tumor. However, an extremely rare occurrence in lung carcinomas is ossification within a primary tumor, and to our knowledge only three cases have been reported. We report a case of pulmonary adenocarcinoma with ossification, and discuss the pathogenesis of intratumoral ossification with a review of the literature.

An increase of intracellular cAMP mediated by prostaglandin E2 (PGE2) has been shown to delay spontaneous apoptosis of neutrophils. It has been demonstrated that a selective agonist for PGE2 receptor subtype 3 (the EP3 receptor) is capable of decreasing cAMP and stimulating phosphoinositide turnover in various types of cells. We investigated the effect of a selective EP3 receptor agonist, ONO-AE-248, on neutrophil viability. ONO-AE-248 rapidly caused a unique form of neutrophil death. The agonist primarily induced morphological changes of the nucleus, including fusion of the lobules, decreased compactness of the chromatin, and blebbing and rupture of the nuclear membrane. This was followed by an increase of plasma membrane permeability and cell lysis. During these processes, neither apoptotic changes such as nuclear condensation, DNA fragmentation, and expression of phospholipid phosphatidylserine on the plasma membrane nor necrotic changes such as chromatin clumping and organelle destruction were apparent in the treated neutrophils. The fatal effect of the agonist might be specific for neutrophils because it failed to promote the rapid death of other types of cells. Although activation of neutrophils by ONO-AE-248 was not evident, experiments using metabolic inhibitors demonstrated that the agonist caused neutrophil death via the activation of protein kinase C in the presence of intracellular ATP. These findings indicated that EP3 receptor-mediated signals might promote a novel form of neutrophil death, which differs from typical apoptosis or necrosis.

Total amounts of nm23 protein and relative levels of H1 and H2 isoforms were studied in 27 fresh-frozen samples of pulmonary adenocarcinoma and adjacent non-neoplastic tissues that were obtained at surgery. Semiquantitative immunoblotting with a monoclonal antibody (Pan-242) against nm23 protein demonstrated both isoforms, recognized as 20.5 kDa for H1 and 18.5 kDa for H2, to be present in all cases. Both H1 and H2 levels in neoplastic tissues were higher than in the corresponding non-neoplastic samples. Expression of H2 was usually greater than of H1. The H2/H1 ratio varied from 1.9 to 14.1 (mean value 5.2) in non-neoplastic tissues and 1.0-5.9 (mean value 2.5) in neoplastic tissues, although this ratio did not correlate with any prognostic factor like tumor size, nodal status or distant metastasis (TNM tumor stage). H1 and H2 levels were significantly lower (mean values 4.3 and 2.4) in well-differentiated than in moderately and poorly differentiated adenocarcinomas (8.3 and 3.0) (P < 0.03 and P < 0.05, respectively). These data indicate that H1 and H2 isoform levels correlate with histological differentiation, but not the metastatic potential or stage of pulmonary adenocarcinoma.

Parathyroid hormone-related protein (PTHrP) is frequently produced in pancreatic endocrine tumors. PTHrP is synthesized as the precursor pro-PTHrP and undergoes a series of posttranslational processing reactions, among which cleavage of a 12 amino acid sequence from its precursor is crucial for the biological activation of PTHrP. This cleavage is catalyzed by furin, a proprotein-processing endoprotease that cleaves the consensus sequence-Arg-X-(Lys/Arg)-Arg ↓ X-. We previously reported that furin is highly expressed in rat pancreatic islets during the perinatal stage and that the expression of furin in pancreatic β cells induces faster cell growth. From this, we postulated that furin may be co-expressed with PTHrP in insulinomas. We immunostained insulin, PTHrP, and furin in 21 human pancreatic endocrine tumors: 10 insulinomas, 5 VIPomas, 4 gastrinomas, and 2 somatostatinomas. Of these 21 endocrine tumors, furin was positively stained in all 10 insulinomas. Likewise, PTHrP was detected in the same insulinomas. We found one VIPoma and one gastrinoma contained a few insulin-positive cells scatteringly, which were also positive for furin and PTHrP. But other non-insulinoma endocrine tumors did not display furin and PTHrP positivity. We conclude that furin and its substrate pro-PTHrP are co-expressed specifically in insulinomas.

Cardiac dendritic cells are considered to play an important role in the immunoresponse of the heart. However, it is unclear whether these cells occur in human myocarditis and whether they function in similar ways to those in rats. Cardiac samples were obtained from 22 autopsied patients with myocarditis, and compared with 20 age- and sex-matched controls. Formalin-fixed hearts were immunostained by the LSAB method. Cardiac dendritic cells were detectable even in the control hearts (1.5 cells/high power field (HPF)). In the acute phase of myocarditis, the number of cardiac dendritic cells increased up to 12.6 cells/HPF (p

症例は63歳女性で, 検診にて胸部異常陰影を指摘され当院に受診となった. 画像上, 右肺底部に発生した肺腫瘍を考え, 気管支鏡検査を施行したが可視範囲内に異常なく, 生検にても確定診断が得られず開胸術を施行した. 術中の迅速病理診断にて悪性黒色腫と診断され, 右下葉切除術及びリンパ節郭清を施行した. 病理組織学的には, 腫瘍は肺末梢領域に発生しており, 近傍の気管支上皮内には腫瘍性メラノサイトから成るin situ component (いわゆるjunctional change) がみられた. 術後皮膚, 眼など再度全身検索を行ったが, 原発と思われる病変部位は見出せなかったため, 肺末梢に発生した肺原発悪性黒色腫と診断した. 原発性肺腫瘍の中では稀な悪性腫瘍とされており文献的考察を含め報告した.

A pituitary adenoma with neuron-like differentiation in the sella turcica is reported. Sections of the tumor showed a mixture of adenoma cells, ganglionic cells, and neuropil-like structures by light microscopy. Both pituitary adenoma cells and large cells recognized as ganglionic cells by H&E were strongly immunoreactive for both growth hormone (GH) and prolactin (PRL), which indicated that these large cells had properties similar to those of pituitary adenoma cells. Furthermore, electron microscopy (EM) revealed characteristic low electron-dense secretory granules as well as GH-type large electron-dense secretory granules in adenoma cells, neuropils, and swollen bulbs of neuronal endings, which indicated that these three populations may be of the same origin. Furthermore, we could not find typical cell bodies of ganglionic cells by EM. These results are consistent with a hypothesis that attempts to explain the origin of the neuronal components by the neuronal differentiation of adenoma cells. Thus, the best designation of our tumor may be “pituitary adenoma with neuron-like differentiation.”

Apoptosis induced by serum withdrawal in pheochromocytoma PC12 cells is promoted by overexpression of cyclin-dependent kinase 4 (CDK4). We compared CDK4-promoted apoptosis with that induced by serum withdrawal alone in PC12 cells. Protein synthesis inhibitors did not prevent apoptosis in parental cells, but prevented the promotion of apoptosis by CDK4 overexpression. Nerve growth factor, basic-fibroblast growth factor, and Bcl-2 proteins protected both parental and CDK4-overexpressing cells from apoptosis. However, insulin-like growth factor-I and Bcl-X(L) protein only partially inhibited apoptosis in the CDK4-overexpressing cells. Bcl-2 or Bcl-X(L) had no significant effect on CDK4 kinase activity in both cell lines. These results suggest a novel CDK4-mediated apoptotic cascade which is normally restrained, but which is activated by CDK4 overexpression. This apoptotic cascade should eventually converge with the cascade induced by serum withdrawal in normal PC12 cells. We discuss the interactions among these apoptotic cascades and the points where anti-apoptotic agents act.

Aims We present an unusual case of leiomyoma with a clear and granular cell pattern in which there was immunohistochemical evidence of transformation to a histiocytic phenotype. Methods and results A 64-year-old man presented with mild scrotal swelling and pain. A local excision was performed after the clinical diagnosis of epidermal inclusion cyst. In the pathological specimen, another tumour nodule was identified which was composed predominantly of clear cells, with an occasional mixture of granular cells. Immunohistochemical analysis demonstrated positive staining for vimentin, lysozyme, CD68 and HAM56, but complete negativity for desmin, α-smooth muscle actin, HHF35, S100 protein, neurone-specific enolase and CD34. Ultrastructural study revealed dilated rough endoplasmic reticulum, glycogen granules, abundant vacuolar structures and also thin microfilaments with subplasmalemmal dense bodies. Conclusions Based on these findings, we have interpreted it to be a rare case of leiomyoma with extensive clear cell and granular cell degeneration (combined clear and granular cell leiomyoma). This complete transformation of the immunohistochemical profile into the histiocytic phenotype has not been previously described in the literature.

Growth hormone-releasing hormone (GHRH) stimulates growth hormone (GH) gene transcription, synthesis, and secretion of growth hormone via growth hormone-releasing hormone receptor (GHRH-R). In a previous study using reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blotting, GHRH-R mRNA was detected in all types of pituitary adenomas. On the other hand, in a recentin situ hybridization (ISH) study of 16 adenomas, including GH (n=8), PRL (n=1), ACTH (n=2), gonadotroph (n=4), and null-cell (n=1) adenomas, GHRH-R mRNA expression was observed only in GH adenomas and one gonadotroph adenoma. Thus, the extent of GHRH-R mRNA in pituitary adenomas is not clear. To clarify these different findings, we investigated the expression of GHRH-R mRNA in various types of human pituitary adenomas, including GH (n=7), PRL (n=4), ACTH (n=3), gonadotroph (n=8), and null-cell adenomas (n=13) using conventional ISH and the CARD-ISH technique, which is more sensitive than previous nonisotopic ISH techniques. By conventional ISH, GHRH-R was found in 71% of GH, 50% of PRL, 67% of ACTH, 12% of gonadotroph, and 8% of null-cell adenomas. By catalyzed reporter deposition-in situ hybridization (CARD-ISH), GHRH-R mRNA was expressed in 100% of GH, 50% of PRL, 67% of ACTH, 62% of gonadotroph, and 70% of null-cell adenomas. Hybridization with the control sense probe was consistently negative. These results show that GHRH-R mRNA is expressed in all types of adenomas with GH adenomas showing the strongest signal for GHRH-R mRNA, suggesting that GHRH-R has a role mainly in the function of GH adenomas, but may also play a role in tumor growth and/or function of other types of adenomas. These experiments also show that CARD-ISH can be used to detect low copy numbers of specific mRNAs because of the increased sensitivity of this technique.

To elucidate the mechanism of tumor extension in human pulmonary adenocarcinoma, we immunohistochemically investigated the expression of cell cycle regulator proteins in 54 small adenocarcinomas less than 3 cm in diameter. The Ki-67-labeling index was significantly higher in the periphery of the tumor nodule than in the center. This proliferative potential correlated well with coexpression of cdk2 and cyclin A. p27, one of the cdk inhibitors, was highly expressed in normal bronchial epithelial cells. Peripherally located tumor cells expressed p27 at an intermediate level, but at a higher frequency and level than those in the center. Expression of p21 was also predominant in the periphery. Furthermore, the expression patterns of p21 and p27 were reciprocal. In vitro kinase assays further demonstrated higher cdk2 kinase activity in the periphery. These results suggest that: (i) within an emerging extension made up of peripherally located tumor cells, their high proliferative potential gradually wanes as their relative topographical position becomes more central in the expanding tumor; (ii) peripherally located tumor cells maintain their proliferative potential by higher cyclin A-cdk2 complex activity; and (iii) intermediate expression of p21/p27 in the peripherally located cells promotes higher cyclin A-cdk2 kinase activity, whereas high p21/p27 expression in nonneoplastic cells inhibits kinase activity.

Langerhans cell histiocytosis (LCH) has been thought to be a disorder of immune regulation, and increasingly, evidence showing that the tissue damage in LCH involves lymphokines and pro-inflammatory cytokines is reported. We detected human cytomegalovirus (HCMV)-DNA in LCH cells in the foci of LCH lesions by immunohistochemistry, in situ hybridization and PCR. HCMV was detected in the nuclei and/or cytoplasm of LCH cells in 9 of 27 LCH cases by immunostaining. HCMV was probably an early antigen. In situ hybridization revealed signals for HCMV-DNA only in the nuclei of LCH cells in 10 of the 27 LCH cases. PCR analysis was performed in 20 of the LCH cases, and HCMV-DNA was detected in 7 of these. All 7 positive cases were also positive for HCMV by ISH and IHC. These findings suggested that early phase infection or reactivation of HCMV occurred in the LCH lesions. HCMV infection may be accompanied by impaired cytokine production. Our study also suggested a relationship between HCMV infection and expression of TNFalpha. In tissues affected by LCH, dermatopathic lymphadenopathy or malignant fibrous histiocytoma and in normal tissues no signals for Epstein-Barr virus-RNA were detected. These findings suggest that in some cases LCH is associated with HCMV infection.