福嶋 敬宜

Intraductal papillary neoplasm of bile duct (IPNB) was described as a preinvasive neoplastic lesion of the biliary tract in the 2010 World Health Organization (WHO) classification. Although a number of studies have since been conducted on IPNBs, controversy remains, particularly regarding the standardization of its definition. Meetings by Japanese and Korean expert pathologists were held twice to resolve the pathological diagnostic aspects of IPNB. Through round-table discussions and histological reviews, we reached the common understanding that IPNBs diagnosed according to the criteria of WHO 2010 are characterized by intraductal predominant papillary or villous biliary neoplasms covering delicate fibrovascular stalks and are classified into two types pathologically. One type (type 1 IPNB) is histologically similar to intraductal papillary mucinous neoplasms of pancreas, and typically develops in the intrahepatic bile ducts, while the other (type 2 IPNB) has a more complex histological architecture with irregular papillary branching or with foci of solid-tubular components and typically involves the extrahepatic bile ducts. This report states the diagnostic pathologic features of IPNB proposed by WHO 2010. Since currently, the concept of IPNB is still confusing, the proposed diagnostic pathologic features stated here will be of use for future clinicopathological and molecular analyses toward consensus building of IPNB.

In 1998, a 61-year-old female was found to have multiple liver tumors. She was admitted to our hospital for further evaluation of the tumors in 2001. Based on histological examination, the tumors were diagnosed as epithelioid hemangioendothelioma (EHE) because the tumor cells were positive for markers of vascular endothe-lium, including CD31, factor VIII, and CD34. The tumors were located in both hepatic lobes, and multiple lung metastases were suspected. Furthermore, the tumors had no indication of partial hepatectomy and liver transplantation. In addition, specific chemotherapy and molecular-targeted agents were not available then. Thus, we carefully monitored the patient without administering any specific treatment. During the observation period, the tumor size and number remained unchanged. Follow-up CT revealed a ring enhancement noted in 2001 that disappeared by 2005. Remarkably, the patient survived for ＞20 years after being diagnosed with hepatic HEE and without being given any specific treatments for hepatic EHE.

The diagnosis of cardiac sarcoidosis (CS) has become easier due to advances in imaging modalities, but we sometimes encounter difficult-to-diagnose patients. We herein report the case of a 60-year-old Japanese woman who was diagnosed with isolated CS, although she also met the diagnostic criteria of arrhythmogenic right ventricular cardiomyopathy (ARVC). A histological examination by an endomyocardial biopsy of the right ventricle revealed the typical findings of granulomatous change for CS. Although she did not show any characteristics of systemic sarcoidosis, oral prednisolone treatment was introduced, and she achieved a good response. This case shows that the characteristics of CS can overlap with the diagnostic criteria of ARVC, and that a histological examination is essential for the correct diagnosis of CS.

Background and study aims Tumor seeding after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is rare. A 53-year-old man underwent transesophageal EUS-FNA for diagnosis of a 6-cm mass in the mediastinum as seen by computed tomography (CT). Four weeks later, repeat CT scan revealed a mass in the esophageal wall. Upper gastrointestinal endoscopy confirmed a lesion in the mid-esophagus, which was biopsied and found to be consistent with needle tract seeding after EUS-FNA. Tumor seeding in the gastrointestinal wall or peritoneum after EUS-FNA is rare, but may adversely affect the prognosis. Indications for EUS-FNA must be carefully considered.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a vascular disorder of unknown etiology characterized by severe asthma, eosinophilia, and granulomatous vasculitis. It is sometimes associated with gastrointestinal lesions, although perforations are uncommon. Corticosteroids are commonly used in the treatment of patients with EGPA; however, they may impair tissue repair and induce fibrotic changes in the vascular intima, which can lead to vascular occlusion, ischemia, and perforation. The anti-inflammatory properties of corticosteroids may mask symptoms of gastroduodenal ulcers or other intra-abdominal conditions, which can lead to a delay in diagnosis. From January 1, 2001 to December 31, 2014, 71 patients underwent surgery for small intestinal perforations. Of these, 4 operations were performed on 3 patients with EGPA who were receiving corticosteroids. We retrospectively reviewed the clinical and pathologic features of these patients. All 3 patients with EGPA were men, with a mean age of 56 years. The length of resected intestine ranged from 10 to 60 cm. Histopathologic examination revealed ulcers and perforations of the small intestine associated with vasculitis, compatible with EGPA. All patients had an uneventful postoperative course. Patients with EGPA presenting with abdominal pain must be carefully evaluated for possible intestinal perforation, especially those receiving corticosteroid therapy.

Unilateral multiple adrenocortical micronodules (UMNs) constitute a rare subset of primary aldosteronism (PA) characterized by the hypersecretion of aldosterone derived from multiple small nodules in the zona glomerulosa of the unilateral adrenal grand. This case study describes a 49-year-old man with PA and UMNs who presented with muscle cramps at rest due to hypokalemia. The patient had a 6-year history of hypertension treated with antihypertensive drugs. Imaging studies revealed bilateral adrenal nodules as large as 5mm. Adrenal venous sampling confirmed unilateral PA; therefore, the patient underwent the removal of the affected adrenal gland. Macroscopically, the removed adrenal gland exhibited irregular adrenocortical thickening accompanied by ill-defined, adrenocortical macronodules as large as 6mm. The zona glomerulosa was histologically hyperplastic. However, an immunohistochemistry test of the steroidogenic enzymes revealed that these macronodules and the hyperplastic glomerular layer tested negative for CYB11B2. Moreover, we observed adrenocortical micronodules as large as 0.5mm that tested immunohistochemically positive for CYP11B2 and HSD3B2 but negative for CYP17A1 and CYP11B1. Thus, UMNs were diagnosed. This case instructively indicates that a grossly or histologically detectable nodular lesion is not necessarily a culprit lesion for PA. Therefore, functional histopathology is indispensable for the correct subclassification of PA.

Pathological complete response (pCR) is considered to be a useful prognostic marker for neoadjuvant chemotherapy to improve the survival rate of patients with operable breast cancer. In the present study, we identified differentially expressed microRNAs (miRNAs) between pCR and non-pCR groups of patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer who received neoadjuvant chemotherapy with trastuzumab. Expression profiles were examined by miRNA microarrays using total RNA extracted from formalin-fixed, paraffin-embedded tissues from pretreatment biopsy specimens. Significant differences were observed in miRNAs associated with pCR between the luminal B-like (HER2-positive) and HER2posi-tive (nonluminal) subtypes, which were further classified according to their estrogen receptor (ER) status. Prediction models constructed with differentially expressed miRNAs performed well. In conclusion, the combination of miRNA profiles and ER status may improve the accuracy of pCR prediction in patients with HER2-positive breast cancer and enable the development of personalized treatment regimens.

INTRODUCTION: Pancreatic neuroendocrine tumors are rare. Treatment includes aggressive local management of the primary lesion and metastases, and systemic somatostatin. This is the first report of an isolated metachronous metastasis to the adrenal gland from a pancreatic neuroendocrine tumor that presented 90 months after the primary tumor.PRESENTATION OF CASE: The patient presented as a 53yo man with a left upper quadrant mass and synchronous metastases to the spleen and liver (pancreatic neuroendocrine tumor T4NOM1, Stage IV), which were resected (CD56-, synaptophysin+, chromogranin+, Ki-67 < 1%). Over the next 90 months, he underwent five procedures to treat hepatic recurrences (2 liver resections and 3 percutaneous radiofrequency ablations). Serum PIVKA levels were elevated prior to treatment of four of six lesions and returned to baseline after therapy. He presents now, asymptomatic, with a right adrenal mass found on routine imaging and no other lesions. Serum PIVKA was elevated to 44 mg/dL. The adrenal gland was resected and shown to be a metastasis (CD56+, synaptophysin+, chromogranin+, Ki-67 15-20%).DISCUSSION: This patient's clinical course reflects aggressive local therapy of the primary lesion and multiple metastatic lesions to three organs (liver, spleen, adrenal) over nearly eight years. The utility of serum PIVKA levels in patients with pancreatic neuroendocrine tumors is not previously reported and needs further investigation.CONCLUSION: This patient has a pancreatic neuroendocrine tumor with metastases to the spleen, liver and adrenal gland and elevated PIVKA levels with recurrent disease. These unique clinical features add to the diversity of clinical presentation of these rare tumors. (C) 2017 The Author(s). Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd. This is an open access article under the CC BY-NC-ND license.

Ovarian non-gestational choriocarcinomas co-existing with adenocarcinoma are extremely rare and have been reported as epithelial ovarian carcinomas of a "non-germ cell origin" with "choriocarcinomatous differentiation". Although the cellular origin of non-gestational choriocarcinoma may be post-meiotic ovarian germ cells or the dedifferentiation of epithelial ovarian carcinoma, detailed genetic evidence has not yet been obtained to support this. We herein present a case of ovarian non-gestational choriocarcinoma co-existing with adenocarcinoma in a 29-year-old woman. The tumor rapidly increased in size and lung metastases appeared soon after parturition. We genetically demonstrated that the cellular origin of ovarian non-gestational choriocarcinoma was a post-meiotic germ cell derivation using a short tandem repeat analysis. The co-existing adenocarcinoma component was also shown to be of the same germ cell origin. These tumors showed the same homozygous pattern. A molecular genetic approach may be important for understanding the clinicopathological features of such tumors.

Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy with poor prognosis and its incidence is increasing worldwide. Recently, several types of cells have been considered as the origin of ICC, namely cholangiocytes, liver progenitor cells, and hepatocytes. Here, we have established a novel mouse model of ICC by liver-specific Kras activation and Pten deletion. An activating mutation of Kras in combination with deletion of Pten was introduced in embryonic hepatic bipotential progenitor cells (so-called hepatoblasts) and mature hepatocytes using the Cre-loxP system. As a result, liver-specific Kras activation and homozygous Pten deletion cooperated to induce ICCs exclusively. In contrast, Kras activation in combination with heterozygous Pten deletion induced both ICCs and HCCs, whereas Kras activation alone resulted in HCCs but not ICCs. Furthermore, a cell-lineage visualization system using tamoxifen-inducible Cre-loxP demonstrated that the ICCs did not originate from hepatocytes but from cholangiocytes. Our data suggest that mice carrying liver-specific Kras activation in combination with homozygous Pten deletion should be useful for the investigation of therapeutic strategies for human ICC.

Purpose: Endocrine cell carcinoma, according to the Japanese classification criteria for colorectal cancer, corresponds to neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma (MANEC), as defined in the 2010 World Health Organization (WHO) classification. We retrospectively reviewed the clinical features of patients with these tumors diagnosed and treated at our institution. Methods: The clinicopathological features of endocrine cell carcinomas of the colon and rectum diagnosed by neuroendocrine markers from January 2000 to December 2012 were retrospectively evaluated in 12 patients. Results: Surgical specimens were obtained from eight of the 12 patients. MANEC was diagnosed in six patients and NEC in one. One tumor was unclassifiable. The tumors were not resected in four patients, and all died within 3 months. Of the eight patients who underwent resection, four received an R0 resection, two of whom underwent adjuvant chemotherapy and survived more than 5 years. One patient who underwent an R2 resection and continuous chemotherapy survived for 53 months. One patient with NEC underwent surgery and radiotherapy, and died 17 months later. Conclusion: Most endocrine cell carcinomas of the colon and rectum reviewed were MANECs. Though their prognosis was generally poor, chemotherapy may be effective in some patients.

Introduction Neuroendocrine tumors of the colon and rectum are relatively rare compared to sporadic colorectal carcinoma. There are few reports of neuroendocrine tumors of the colon and rectum in patients with ulcerative colitis. Presentation of case A patient with sigmoid colon carcinoma with focal neuroendocrine features is presented. A 32-year-old man, who had been followed for ulcerative colitis for 14 years, was found to have carcinoma of the sigmoid colon on routine annual colonoscopy, and he underwent laparoscopic total colectomy. Pathologic examination showed sigmoid colon adenocarcinoma with focal neuroendocrine features. Discussion Most colorectal carcinomas associated with inflammatory bowel disease are histologically similar to the sporadic type, and tumors with neuroendocrine features are very unusual. Conclusion Very rare case of sigmoid colon carcinoma with neuroendocrine features arising in a patient with UC was described.

We herein report an asymptomatic 65-year-old male with localized pleural amyloidosis mimicking malignant pleural mesothelioma. He had a history of exposure to asbestos and was admitted for investigation of an abnormal pleural thickness detected by chest radiography. Positron emission tomography showed elevation of standardized uptake value corresponding to the pleural thickness. Partial pleurectomy including the tumor was performed for the purpose of diagnosis and local disease control. The pathological examination showed that the tumor was pleural amyloidosis. The tumor was diagnosed as localized primary amyloidosis, because serum monoclonal protein concentration did not increase. Pleural amyloidosis should be considered as a differential diagnosis from pleural mesothelioma.

Although size criteria have been proposed to identify lymph node metastases in patients with rectal cancer, size may not be an accurate predictor. Specimens from consecutive rectal cancer patients who underwent curative-intent radical surgery were examined. The long and short axes of lymph nodes were measured on the glass slides using micrometer calipers. The pathologic diagnosis was used as the reference. The diagnostic accuracy of metastatic status according to lymph node size was evaluated. Overall, 1283 lymph nodes from 78 patients were reviewed. The metastatic rate correlates with the length of both the long and short axes. However, metastases were present even in 1-mm lymph nodes, and the metastatic rate exceeds 5 per cent in lymph nodes measuring 3 mm along both axes. Cutoff values of ≥4 mm and ≥3 mm for the long and short axes result in a sensitivity of 76 per cent and 79 per cent, and a specificity of 36 per cent and 33 per cent, respectively, for each axis. Size criteria alone do not accurately predict the N-stage of rectal cancer. Diminutive lymph nodes, which are not seen on imaging studies, can contain metastatic disease.

International experts met to discuss recent advances and to revise the 2004 recommendations for assessing and reporting precursor lesions to invasive carcinomas of the pancreas, including pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm, and other lesions. Consensus recommendations include the following: (1) To improve concordance and to align with practical consequences, a 2-tiered system (low vs. high grade) is proposed for all precursor lesions, with the provision that the current PanIN-2 and neoplasms with intermediate-grade dysplasia now be categorized as low grade. Thus, high-grade dysplasia is to be reserved for only the uppermost end of the spectrum (carcinoma in situ-type lesions). (2) Current data indicate that PanIN of any grade at a margin of a resected pancreas with invasive carcinoma does not have prognostic implications; the clinical significance of dysplasia at a margin in a resected pancreas with IPMN lacking invasive carcinoma remains to be determined. (3) Intraductal lesions 0.5 to 1 cm can be either large PanINs or small IPMNs. The term incipient IPMN should be reserved for lesions in this size with intestinal or oncocytic papillae or GNAS mutations. (4) Measurement of the distance between an IPMN and invasive carcinoma and sampling of intervening tissue are recommended to assess concomitant versus associated status. Conceptually, concomitant invasive carcinoma (in contrast with the associated group) ought to be genetically distinct from an IPMN elsewhere in the gland. (5) Intraductal spread of invasive carcinoma (aka, colonization) is recommended to describe lesions of invasive carcinoma invading back into and extending along the ductal system, which may morphologically mimic high-grade PanIN or even IPMN. (6) Simple mucinous cyst is recommended to describe cysts &gt;1 cm having gastric-type flat mucinous lining at most minimal atypia without ovarian-type stroma to distinguish them from IPMN. (7) Human lesions resembling the acinar to ductal metaplasia and atypical flat lesions of genetically engineered mouse models exist and may reflect an alternate pathway of carcinogenesis; however, their biological significance requires further study. These revised recommendations are expected to improve our management and understanding of precursor lesions in the pancreas.

Although size criteria have been proposed to identify lymph node metastases in patients with rectal cancer, size may not be an accurate predictor. Specimens from consecutive rectal cancer patients who underwent curative-intent radical surgery were examined. The long and short axes of lymph nodes were measured on the glass slides using micrometer calipers. The pathologic diagnosis was used as the reference. The diagnostic accuracy of metastatic status according to lymph node size was evaluated. Overall, 1283 lymph nodes from 78 patients were reviewed. The metastatic rate correlates with the length of both the long and short axes. However, metastases were present even in 1-mm lymph nodes, and the metastatic rate exceeds 5 per cent in lymph nodes measuring 3 mm along both axes. Cutoff values of &gt;= 4 mm and &gt;= 3 mm for the long and short axes result in a sensitivity of 76 per cent and 79 per cent, and a specificity of 36 per cent and 33 per cent, respectively, for each axis. Size criteria alone do not accurately predict the N-stage of rectal cancer. Diminutive lymph nodes, which are not seen on imaging studies, can contain metastatic disease.

We report a case of sarcomatoid carcinoma of the skin in a 63-year-old man who was treated with the carbon dioxide snow freezing method for a huge congenital pigmented nevus that extended from the right upper extremity to the right trunk during childhood. He had an exophytic red tumor on the nevus in the right upper extremity that grew slowly for 4years and rapidly recently. Histological and immunohistochemical studies revealed both epithelial and mesenchymal malignancy in the same tumor. The epithelial component was composed of basaloid cells forming multiple nests with peripheral palisading, positive for keratins and BerEP4, implying basal cell carcinoma. The mesenchymal component was composed of spindle-shaped cells negative for keratins and positive for vimentin, suggesting sarcoma. This is, to our knowledge, the first report of sarcomatoid carcinoma arising in the primary pigmented nevus that had been treated by the carbon dioxide snow freezing method.

Rosai-Dorfman disease (RDD) is a benign histiocytic proliferative disorder characterized by the accumulation of histiocytes in lymph nodes and various other organs. RDD seldom involves the central nervous system, and cases of purely intracranial RDD are particularly rare. We report a case of purely intracranial RDD involving the brainstem that was diagnosed at autopsy. A 68-year-old woman visited our hospital because of visual disturbances and loss of energy. Magnetic resonance imaging revealed an obscure mass in the brainstem. Despite exhaustive work-ups, the etiology of the intracranial mass remained unclear. The patient died of respiratory depression, and an autopsy was performed for pathological investigation. Macroscopically, a pink pale mass 2.5cm in diameter was found in the brainstem, with no attachment to the dura. Histologically, it was composed of histiocytic cells with incorporation of small lymphocytes (emperipolesis). Immunohistochemical staining revealed that the cells were positive for CD68 and S100 and negative for CD1a, consistent with a diagnosis of RDD. Purely intracranial RDD is extremely rare and considered benign. To date, nine cases (including ours) have been reported. To our knowledge, this is the first case of intracranial RDD with autopsy. Although generally considered benign, RDD involving the brainstem might be lethal.

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are primary pancreatic neoplasms that can act as precursors to invasive adenocarcinoma of the pancreas. The peritumoral stroma has been increasingly recognized to play an important role in many types of tumors. Therefore, to investigate the clinicopathological significance of the peritumoral stroma in IPMNs, we examined the histological features of the peritumoral stroma in each subtype and histological grade of IPMNs. Eighty-two patients with IPMN, who underwent surgical resection, were reviewed clinicopathologically. Intraductal papillary mucinous neoplasms (86 lesions in total) were histologically subclassified into gastric (n = 51), intestinal (n = 22), pancreatobiliary (n = 11), and oncocytic (n = 2) subtypes. Peritumoral histological features between the gastric and intestinal subtypes were evaluated by each histological grade. The results showed that subepithelial edema and inflammatory cell infiltration were more commonly observed in the gastric subtype (74% and 79%, respectively) than in the intestinal subtype (12% and 25%, respectively) of low-grade IPMNs. On the other hand, mucus lakes were more commonly observed in the intestinal subtype (100%) than in the gastric subtype (0%) of high-grade IPMNs. In addition, pancreatobiliary subtype IPMNs tended to exhibit acute inflammation such as neutrophil predominance. This study showed that peritumoral histological features differed among subtypes of IPMNs from low-grade tumors. These differences suggest the possibility that each subtype of IPMNs has a distinct mechanism from an early stage of tumor progression, which is reflected in the properties of the peritumoral stroma. (C) 2015 Elsevier Inc. All rights reserved.

Background: Blue nevus is a benign dermal melanocyte tumor that mainly arises from the skin. We report an extremely rare case of blue nevus in a pediatric patient with extensive progression from the middle ear and inner ear to the nasopharynx through the Eustachian tube. Case Report: A 2-year-old girl with blue tympanum was referred to our department. Computed tomography scans and magnetic resonance imaging were performed, followed by a tissue biopsy and histopathologic evaluations. Radiologic examinations revealed that the lesion had progressed beyond the middle ear into the inner ear and the nasopharynx through the Eustachian tube. Subsequent histopathologic examinations indicated dermal dendritic melanocytic proliferations, but no evidence of malignancy. Based on the clinical and histopathologic findings, we concluded that the lesion was consistent with blue nevus. Discussion: Blue nevus is a relatively common skin lesion. However, no prior reports have described the extension of blue nevus from the auditory organ to the nasopharynx in a pediatric patient. Despite the benign nature of the lesion, the patient experienced profound hearing loss in the affected ear, which necessitates continued monitoring as the lesion may expand with patient growth.

We hypothesized that a reduction in the size of the lymph nodes after neoadjuvant therapy for locally advanced rectal carcinoma would be associated with decreased lymph node metastases and/or a better prognosis. Between March 2006 and April 2012, 71 patients with primary rectal cancer received neoadjuvant chemoradiation therapy (CRT). For all lymph nodes 5 mm or larger in size, the major and minor axes were measured on CT scan images, and the product was calculated. The lymph node size was determined before and after CRT. The patients were divided into three groups based on the lymph node size before and after treatment. Group A exhibited a reduction in size of 60 % or more, Group B a reduction of less than 60 % and Group C had no lymph node enlargement before treatment. The incidence of lymph node metastases on pathological examination was 15 % in Group A and 50 % in Group B (p = 0.006). The five-year disease-free survival in Group A was 84 % compared with 78 % in Group B (log rank p = 0.34). The five-year overall survival in Group A was 92 % compared with 74 % in Group B (log rank p = 0.088). A reduction in the size of enlarged lymph nodes after neoadjuvant therapy may be a useful prognostic factor for recurrence and survival.

Intravascular large B-cell lymphoma (IVLBCL) is classified as a rare type of non-Hodgkin's B-cell lymphoma by the World Health Organization. It is characterized by the presence of lymphoma cells in the lumens of the small vessels of several organs, most notably the skin. Diagnosis of IVLBCL is difficult because of the lack of lymphadenopathy and because lesions need to be histologically confirmed via a biopsy of the affected organs. Random skin biopsy (RSB) of normal-appearing skin is a useful and apparently safe means of evaluating IVLBCL. However, patients with IVLBCL often exhibit thrombocytopenia, and we describe a case in which a patient with thrombocytopenia experienced hemorrhagic shock and died shortly after RSB. For this reason, we reviewed cases of RSB performed at our hospital and found that the middle adipose tissue contained a higher percentage of atypical lymphoid cells than other layers of the skin. On the basis of our findings, we propose a strategy for the safer performance of RSB in IVLBCL patients with thrombocytopenia and coagulation abnormalities.

Direct fast scarlet 4BS（以下，DFS）はアミロイド物質を特異的に染色するが，時としてアミロイドの染色不良や膠原線維への共染を経験する。これらの予防策として，塩を添加することによる染色液の調整法がこれまでいくつか報告されている。本検討では塩の種類・組み合わせに焦点を当て，DFS染色液調整法の検討を行った。DFS染色液に塩化ナトリウム，炭酸ナトリウム，硫酸ナトリウムの3種類の塩をそれぞれ添加した。さらに，これらの塩から任意の2種類を組み合わせて添加したもの，塩を添加しないコントロールを含む計7系列の染色液を作製した。全身性アミロイドーシス（AA型）と診断された剖検例の肝臓パラフィンブロックの連続切片を作製し，各系列のDFS染色液で染色した。染色した切片に対して，（1）アミロイドの染色性，（2）膠原線維への共染の程度を評価した。染色性の評価は，目視に加え，色の差を数値化す