Immunoreactivity for epithelial and neuroendocrine antibodies are useful in the differential diagnosis of lung carcinomas

The histologic classification of pulmonary neoplasms can have important implications regarding appropriate management of patients. Although the histologic classification of lung tumors is predominantly based on morphology, ancillary studies such as immunohistochemistry can be used in difficult cases, and the diagnosis of large cell neuroendocrine carcinoma requires confirmation of neuroendocrine differentiation by immunohistochemistry or electron microscopy. We immunostained 142 lung tumors for B72.3, keratin 34betaE12, keratin 7, keratin 14, keratin 17, synaptophysin, and chromogranin to determine the utility of neuroendocrine markers and epithelial markers in the differential diagnosis. Among neuroendocrine carcinomas (small cell carcinoma and large cell neuroendocrine carcinoma), 84% (37 of 44) were chromogranin positive, 64% (21 of 36 small cell, 6 of 6 large cell neuroendocrine) were synaptophysin positive, 5% (2 of 43) were keratin 34betaE12 positive, 9% (4 of 44) were keratin 7 positive, and 5% (2 of 37) of small cell carcinomas and 50% (3 of 6) of large cell neuroendocrine carcinomas were B72.3 positive. Among non-neuroendocrine carcinomas, 5% (5 of 98) were chromogranin positive, 3% (3 of 96) were synaptophysin positive, and 97% (95 of 98) were positive for either keratin 34betaE12 or keratin 7 and 99% (97 of 98) were positive for either keratin 34betaE12, keratin 7 or B72.3. An antibody panel consisting of keratin 7, keratin 34betaE12, chromogranin, and synaptophysin separated 132 of 141 tumors (94%) into distinct groups. We conclude that immunostaining with both neuroendocrine markers and epithelial markers can be useful in the differential diagnosis of lung neoplasms.     

Neuroendocrine carcinomas (carcinoid tumor) of the thymus. A clinicopathologic analysis of 80 cases

We studied 80 cases of primary thymic neuroendocrine carcinomas. Most patients had symptoms; approximately one third were asymptomatic. All cases were treated by surgical excision. The tumors were divided according to histopathologic features into low- (n = 29), intermediate- (n = 36), and high-grade (n = 15) types. The tumors displayed a variegated histologic appearance and unusual cytologic features. Some cases showed transition from low to high grade within the same tumor mass. Mitotic activity ranged from fewer than 3 to more than 10 mitotic figures per 10 high-power fields, and most tumors displayed marked cellular atypia and areas of necrosis. In 73 patients, the tumor was confined to the anterior mediastinum. Positive immunohistochemical reaction was observed using antibodies for CAM 5.2 low-molecular-weight cytokeratins, broad-spectrum keratin, chromogranin, synaptophysin, and Leu-7. The clinical follow-up obtained in 50 patients correlated well with tumor differentiation. Therefore, the behavior of these tumors seems to correlate with histologic grade, which seems directly proportional to degree of differentiation. We propose replacing the term thymic carcinoid with thymic neuroendocrine carcinoma, which better reflects the aggressive biologic behavior of these tumors in the mediastinal location.     

Primary neuroendocrine tumor of the testis: a study of clinicopathological features

This study aimed to explore the clinicopathological characteristics and differential diagnosis of primary neuroendocrine tumor (G1) of the testis. In this paper, we analyze the clinical, histomorphological and immunohistochemical findings, treatment and prognosis of a patient with primary neuroendocrine tumor of the testis, and discuss the relevant literature. A 52-year-old man presented with a painless testicular swelling since 6 months. Histopathological examination showed that the tumor cells were arranged in island and beam patterns. The tumor cells were uniform, polygonal and had moderately eosinophilic cytoplasm and fine granular nuclear chromatin. Immunohistochemical staining showed that the tumor cells were positive for cytokeratin, CD56, synaptophysin and chromogranin A, and negative for inhibin, placental alkaline phosphatase and alpha-fetoprotein. Primary neuroendocrine tumor of the testis is a rare tumor with characteristic imaging features. Its accurate diagnosis depends on the morphological and immunohistochemical findings. These tumors should be differentiated from metastatic neuroendocrine carcinomas, teratomas with carcinoid, seminomas, Sertoli cell tumors and granulosa cell tumors. The treatment of most primary neuroendocrine tumors involves surgical resection combined with other therapies and usually results in a good prognosis.     

伴有神经内分泌分化的乳腺梭形细胞癌

目的探讨乳腺伴有神经内分泌分化的梭形细胞癌的病理形态学和免疫表型特点及鉴别诊断。方法复习2500例乳腺癌切片,找出以梭形细胞占主要优势（〉80％）的癌5例,其中2例梭形细胞型导管内癌和3例梭形细胞型浸润癌。采用HE、阿辛蓝（AB）／PAS和网织染色,以及用癌胚抗原（CEA）、上皮膜抗原（EMA）、细胞角蛋白（CK7、3413E12、AE1／AE3）、神经元特异性烯醇化酶（NSE）、突触素、嗜铬蛋白（cg）A、Lue-7、波形蛋白,S-100、平滑肌肌动蛋白（SMA）、calponin、雌激素受体（ER）、孕激素受体（PR）、c—erbB-2、E-钙黏素、Ki-67、p53抗体进行免疫组织化学观察。其中4例有随访信息。结果患者平均年龄在68岁。镜下：5例癌细胞形态主要为长梭形的上皮样细胞,3例有少数胞质内空泡状细胞,4例可见散在AB阳性细胞。免疫组织化学5例均表达AE1／AE3、EMA、CEA、E-钙黏素和突触素,CK7有4例表达,NSE阳性3例,CgA和Lue7阳性2例,ER阳性4例,PR阳性2例,1例表达c-erbB-2,1例有灶状波形蛋白阳性。免疫组织化学结果显示2例梭形细胞型导管内癌和1例梭形细胞型浸润性癌是梭形细胞型的神经内分泌癌,另外2例梭形细胞型浸润性癌是伴有神经内分泌分化的化生性癌。随访3例存活（24～58个月）,1例27个月内死亡。结论上皮样梭形细胞和细胞内黏液的出现是乳腺伴有神经内分泌分化癌的一个形态学特点。梭形细胞神经内分泌型导管内癌需要和普通导管增生及导管内乳头状瘤鉴别。梭形细胞型的神经内分泌癌和伴神经内分泌分化的梭形细胞浸润性癌需要与梭形细胞肌上皮肿瘤、恶性黑色素瘤及某些软组织肿瘤鉴别。     

Neuroendocrine differentiation in extrahepatic bile duct carcinomas and its prognostic significance

Neuroendocrine differentiation is known to be one of the prognostic factors in many carcinomas. However, the characteristics of neuroendocrine differentiation are not well elucidated in extrahepatic bile duct (EBD) carcinomas. One hundred ninety-four cases of EBD carcinomas were analyzed using immunohistochemistry with synaptophysin and chromogranin. The tumors were graded as degree 0, 1, and 2 when the positive tumor cells were 5% or less, 6% to 25%, and 26% or more, respectively. Immunohistochemical results were compared with clinicopathologic variables and survival rate. Synaptophysin and chromogranin were positive in 54 (27.8%) and 74 (38.1%) cases, respectively. Thirty-four cases (17.5%) were positive for both synaptophysin and chromogranin, 20 (10.3%) and 40 cases (20.6%) were positive only for synaptophysin and for chromogranin, respectively, and 100 cases (51.6%) were negative for both markers. There was a significant survival difference between overall synaptophysin-positive (median, 27 months) and synaptophysin-negative (38 months) groups (P < .05). However, there was no survival difference between chromogranin-positive and chromogranin-negative groups. There was a significant survival difference between the dual-positive expression to synaptophysin and chromogranin group (median, 21 months) and the dual-negative expression group (median, 35 months; P < .05). In summary, synaptophysin expression was an important prognostic factor because synaptophysin-positive cases showed a worse prognosis than synaptophysin-negative cases. The more tumor cells expressed chromogranin, the poorer the survival. Therefore, immunohistochemical studies for neuroendocrine differentiation may be helpful in routine pathological examinations for evaluating the survival and the prognosis of patients with EBD carcinomas.     

Small cell carcinoma of the cervix: a clinicopathologic and immunohistochemical study of 23 cases

Twenty-three patients with primary small cell carcinoma of the uterine cervix are presented. Their ages ranged between 23 and 63 years (average, 43 years). Blood spotting or vaginal bleeding was the most common clinical presentation. Histologically, the tumors were densely cellular and showed trabecular nesting or a sheet-like pattern. The neoplastic cells had scant cytoplasm, round nuclei, absence of nucleoli, and finely dispersed chromatin. Nuclear molding, single cell necrosis, and high mitotic activity were found in all tumors. There was a minor component of large cell neuroendocrine carcinoma in three cases, while foci of adenocarcinoma were identified in two cases. Immunohistochemical studies were performed in all 23 tumors which showed immunoreactivity for cytokeratin. Ten small cell carcinomas were immunoreactive for chromogranin, 13 for synaptophysin, and 10 expressed p53 protein. Treatment modalities included hysterectomy alone or combined with chemotherapy and/or radiation therapy. A few patients received chemotherapy and/or radiation alone. Follow-up information was obtained in 22 cases; 15 patients died of tumor between 6 and 43 months, while seven patients have remained alive 12 to 273 months. One patient was lost to follow-up. Small cell carcinoma of the cervix is a highly aggressive neoplasm. However, early diagnosis and combined therapeutic modalities may lead to longer survival in some patients. Although the use of immunohistochemistry may be helpful in the diagnosis, small cell carcinoma still remains a morphologic diagnosis.     

原发性浅表食管小细胞神经内分泌癌15例的临床病理学特征

目的 分析原发性浅表食管小细胞神经内分泌癌的临床病理学及免疫组织化学特征,以寻找浅表食管小细胞神经内分泌癌合适的诊断标志物及治疗方法.方法 回顾性分析15例原发性浅表食管小细胞神经内分泌癌的临床病理学特征,并采用免疫组织化学MaxVision方法检测嗜铬粒素A(CgA)、神经元特异性烯醇化酶(NSE)、突触素、CD56、甲状腺转录因子-1(TTF-1)、细胞角蛋白AE1/AE3、CK34βE12及CK10/13在食管小细胞神经内分泌癌中的表达.结果 原发性浅表食管小细胞神经内分泌癌的发病率占同期浅表食管癌的4.8％(15/312).患者中位生存时间19个月,平均生存时间23.7个月.1、2和5年生存的分别有10、5和1例.免疫组织化学标志物NSE、突触素、AE1/AE3均为阳性,CD56阳性14例,TTF-1阳性9例,CgA阳性8例,CK34βE12阳性1例,CK10/13均为阴性.结论 原发性浅表食管小细胞神经内分泌癌恶性度高,进展快速,预后很差.建立在放化疗联合外科切除基础上的系统性治疗或许有助于延长患者的生存期.NSE、突触素、AE1/AE3、CD56、TTF-1、CgA在食管小细胞神经内分泌癌中的高表达对其诊断及鉴别诊断具有一定应用价值.     

Peripancreatic paraganglioma mimics pancreatic/gastrointestinal neuroendocrine tumor on fine needle aspiration: Report of two cases and review of the literature

Cytologic diagnosis of extra‐adrenal paraganglioma presenting as a peripancreatic mass is challenging with a high error rate due to its rarity. We report two cases of peripancreatic masses identified by radiology. Endoscopic ultrasound‐guided fine needle aspiration (FNA) of the masses showed a moderately cellular tumor composed of small to medium sized neoplastic cells with round to oval nuclei, arranged singly and in loose clusters. Focal rosette‐like structures were present. The cells were positive for neuroendocrine markers (synaptophysin and chromogranin). A diagnosis of a neoplasm with neuroendocrine differentiation and neuroendocrine tumor was made respectively on FNA for each case. The subsequent surgical resection of the tumors revealed peripancreatic paraganglioma. Although paraganglioma has been reported in the literature, the detailed comparison of perpancreatic paraganglioma versus pancreatic/gastrointestinal neuroendocrine tumor is still lacking. Therefore using these two cases with literature review, we wish to illustrate the differential diagnosis between these two entities based on cytomorphology and immunohistochemical study.     

Neuroendocrine differentiation in pure type mammary mucinous carcinoma is associated with favorable histologic and immunohistochemical parameters.

Mucinous carcinoma of the breast is a specific good prognostic type malignancy occurring in elderly patients. Neuroendocrine differentiation has long been described in mucinous carcinoma, but the significance of such finding is uncertain. We evaluated the neuroendocrine differentiation profiles of 38 cases of pure mucinous carcinoma and compared the clinicopathological differences between those with and those without neuroendocrine differentiation. The parameters assessed included patients' age, tumor size, nuclear grade, axillary lymph node status at time of diagnosis, percentage area of intratumoral mucin, and the expression of estrogen and progesterone receptors, cerbB2 oncoprotein, and three neuroendocrine markers, namely neurone-specific enolase, chromogranin, and synaptophysin by immunohistochemistry. Patients' outcome and follow-up period were also documented. Of the 38 cases of pure mucinous carcinoma, 28, 11 and six cases showed positive staining for 1, 2 and 3 of the neuroendocrine markers. For all the groups with variable neuroendocrine differentiation and compared to those without such differentiation, they all showed older patients' age, higher proportion of tumors with lower nuclear grade, lower incidence of axillary lymph node metastasis, a higher progesterone receptor, and lower cerbB2 oncoprotein expression. No difference was detected between tumor size, intratumoral mucinous area, and estrogen receptor status. In all, 37 patients did not have distant metastases or local recurrences at the end of follow-up period, while one patient with coexisting high-grade ductal carcinoma in situ at time of diagnosis died of breast carcinoma. Our findings suggest that the identification of neuroendocrine differentiation in pure mucinous carcinoma is associated with more favorable histologic and immunohistochemical parameters.     

Tumor of the liver (hepatocellular and high grade neuroendocrine carcinoma): a case report and review of the literature

We describe a rare hepatic collision tumor composed of a hepatocellular carcinoma and a high-grade neuroendocrine carcinoma. The patient, a 50-year-old man, underwent a partial hepatectomy because of a 5.0-cm mass. The tumor had two distinctive patterns. The majority of the tumor was a high-grade neuroendocrine carcinoma with features of a small cell carcinoma that was positive for chromogranin, synaptophysin, and cytokeratin 19 and negative for hepatocellular antigen and alpha-fetoprotein (AFP). The second component was a moderately differentiated hepatocellular carcinoma that was positive for hepatocellular antigen and AFP and negative for neuroendocrine markers. The two tumors were separated by fibrous bands. In areas where they collided, there was no transition or intermingling of cells between the two components, thus, it is different from the combined type of tumors. After removal of the tumor, the patient had intrahepatic and mesenteric recurrences within a follow-up period of 16 months.     

Primary hepatic carcinoid and neuroendocrine carcinoma: Clinicopathological and immunohistochemical study of five cases

Primary hepatic carcinoid and neuroendocrine carcinoma (NEC) are rare tumors. We experienced three carcinoids and two NEC originating in the liver during the past 25 years and attempted to elucidate the clinicopathological and immunohistochemical features of these tumors. The patients had no endocrine symptoms despite two of them having elevated plasma serotonin. Three of the five patients died of the tumor after operation with an average survival time of 20.6 months. All tumors were large (up to 26 cm in diameter), four of them solitary and one multinodular, and were not associated with liver cirrhosis. The carcinoid tumors showed insular, trabecular or glandular arrangement of argyrophilic cells, whereas in the NEC this histological pattern was distorted. Immunohistochemically the tumors showed expression of chromogranin A (all cases), chromogranin B (three cases), pancreastatin and chromostatin (four cases, respectively), prohormone convertase PC3 (three cases), carcinoembryonic antigen (CEA) and CA19-9 (two cases), cytokeratin 56 kDa (three cases), 160 kDa neurofilament (two cases) and neuron-specific enolase (two cases). Serotonin and glucagon were sporadically detected in two tumors. The most useful marker to confirm the diagnosis was chromogranin A, which was cleaved to pancreastatin and chromostatin in the tumor tissue, and was more reliable than other markers of neuroendocrine differentiation.     

CD56 expression in basaloid anal squamous cell carcinoma – A potential diagnostic pitfall

Anal squamous cell carcinoma (SqCC) is a morphologically heterogeneous entity. Basaloid and non-keratinizing anal SqCC may be confused with other tumors including neuroendocrine carcinoma due to morphologic overlap, and expression of neuroendocrine markers is not well-studied in anal SqCC. Prompted by a case of anal SqCC that was initially misdiagnosed as neuroendocrine carcinoma on the basis of morphology and CD56 expression, we retrospectively examined the expression of neuroendocrine markers CD56, synaptophysin, and chromogranin in 48 cases of basaloid anal SqCC, with clinicopathologic correlation. HPV16 was identified in 46 cases, HPV33 in one case, and one case was HPV-negative. Three (6.3%) cases demonstrated CD56 expression, including two with diffuse and one with focal expression. Two CD56-positive cases demonstrated basaloid morphology with peripheral palisading and the other demonstrated adenoid cystic/cylindroma-like morphology. None of the cases showed significant synaptophysin or chromogranin expression. The three cases expressing CD56 were HPV16-positive, and one demonstrated a CTNNB1 mutation. There was no difference in clinicopathologic features including stage, outcome, or HPV status, between CD56-positive and negative groups. Our findings support that CD56 expression is infrequently expressed in anal SqCC and is not indicative of neuroendocrine differentiation in the absence of expression of more specific neuroendocrine markers such as synaptophysin and chromogranin. Pathologists should be aware that CD56 expression may occur in basaloid anal SqCC and is a diagnostic pitfall due to morphologic overlap with neuroendocrine carcinoma and other tumors including basal cell carcinoma.     

Neuroendocrine carcinoma of the liver associated with dermatomyositis: autopsy case and review of the literature

Reported herein is an autopsy case of primary hepatic neuroendocrine carcinoma associated with dermatomyositis. A 71-year-old Japanese man, who was diagnosed with dermatomyositis 5 months before death, had multiple tumors within a non-cirrhotic liver. Histopathologically, the tumors were composed of small- and medium-sized round cells with clear cytoplasm arranged in nests, sheets or rosettes. Immunohistochemically, the tumor cells were positive for chromogranin A, neuron-specific enolase and CD56 and were negative for synaptophysin. This tumor was diagnosed as a primary hepatic neuroendocrine carcinoma with metastasis to the lung, gallbladder and lymph nodes around the pancreas and aorta; no primary lesions were detected in any other organ. The tumor cells were also positive for cytokeratin 7, cytokeratin 19 and epithelial membrane antigen but were negative for anti-hepatocyte antibody and AFP. These findings suggest that the tumor originated in intrahepatic bile duct epithelium. Various cancers have been reported in patients with dermatomyositis, but only seven cases of dermatomyositis associated with primary liver cancer have been reported. To the best of the authors' knowledge, this is the first report of dermatomyositis associated with primary hepatic neuroendocrine carcinoma.     

Mixed small cell carcinomas of the uterine cervix: prognostic impact of focal neuroendocrine differentiation but not of Ki-67 labeling index

Small cell neuroendocrine carcinomas sometimes represent a non-small cell component. Because of infection with the high-risk human papillomavirus of small cell carcinomas (SmCCs), several host cell regulatory proteins are altered, thus causing altered proliferative activity. Knowledge regarding the prognostic impact of focal neuroendocrine differentiation in mixed SmCCs and the value of proliferative activity in these tumors is very limited. Small cell carcinomas were selected for immunohistochemical staining with neuroendocrine markers and Ki-67. In cases with mixed tumors, the percentage of the SmCC component was calculated and correlated with survival. Of 677 tumors, 9 (1.3%) were classified as SmCCs after Grimelius staining (8/9 positive tumors) and immunohistochemical reaction against neuron-specific enolase, chromogranin A, synaptophysin (7/9 positive tumors), and CD56 (8/9 positive tumors); all specimens were positive for at least 2 of these. CD99 staining was completely negative. Two thirds of the SmCCs showed non-small cell differentiation. Four patients died of the tumor after a median time of 36.7 months (range, 15-56 months). Even an SmCC component of 17% was associated with a fatal course. Small cell carcinoma represented a significantly lower proliferation (Ki-67 labeling index) than did the non-small cell component in the same tumor (12.8% vs 70.8%; P < .001). Even a small SmCC component in mixed carcinomas of the uterine cervix was associated with adverse outcome. Proliferative activity, determined by Ki-67 labeling index, is of no prognostic value.     

Thymic neuroendocrine carcinomas with combined features ranging from well-differentiated (carcinoid) to small cell carcinoma. A clinicopathologic and immunohistochemical study of 11 cases

We reviewed 11 cases of primary thymic neuroendocrine carcinomas with combined features ranging from well-differentiated to poorly differentiated neuroendocrine carcinoma. For 3 asymptomatic patients, tumors were discovered during routine examination. Presentation in the other patients was as follows: Cushing syndrome, 2 patients; chest pain, 3 patients; superior vena cava syndrome, 1 patient; and hypercalcemia and hypophosphatemia, 1 patient. No clinical data were available for the 11th patient. All tumors were located in the anterior mediastinum and treated by surgical excision. The lesions were large and well-circumscribed with areas of hemorrhage and necrosis. They were characterized by areas showing a proliferation of monotonous, round tumor cells adopting a prominent organoid pattern admixed with areas showing sheets of atypical cells with hyperchromatic nuclei, frequent mitoses, and extensive areas of hemorrhage and necrosis. Immunohistochemical studies performed in 6 cases showed strong CAM 5.2 low-molecular-weight cytokeratin positivity in all cases, chromogranin and synaptophysin positivity in 4, Leu-7 in 3, and focal positivity for p53 in 2. Follow-up information for 9 cases showed that all patients died of their tumors between 1 and 4 years after diagnosis. The present cases highlight the heterogeneity of neuroendocrine neoplasms and reinforce the notion that these tumors form part of a continuous spectrum of differentiation.     

Gallbladder Adenocarcinoma with Florid Neuroendocrine Cell Nests and Extensive Paneth Cell Metaplasia

We report a unique case of gallbladder adenocarcinoma associated with florid neuroendocrine cell nests and extensive Paneth cell metaplasia that has not been described previously. The patient was a 79-yr-old woman with a pedunculated, polypoid mass in the gallbladder. Microscopically, the mass was composed of tumor cells showing tubular and papillary growth patterns, consistent with well-differentiated adenocarcinoma. One-third or more of the tumor cells showed Paneth cell appearance. Goblet cell-type tumor cells were also intermingled. In addition, neuroendocrine cell nests, that were connected to the neoplastic glands, were scattered throughout the stroma. Immunohistochemically, the labeling index of MIB-1 in adenocarcinoma cells including Paneth cell-type carcinoma cells was approx 40%. Neuron-specific enolase, chromogranin A, and synaptophysin were positive in the neuroendocrine cells forming solid nests and intermingled within neoplastic glands. They were immunopositive for serotonin but negative for insulin, glucagon, somatostatin, and pancreatic polypeptide (PP). Although MIB-1-positive neuroendocrine cell nests were very few with weak staining, we think that the neuroendocrine cell nests were neoplastic in nature. The formation of the multifocal neuroendocrine nests may be a consequence of the trophic effects of unknown substance(s), which can promote serotonin-producing neuroendocrine cells to proliferate. We postulate that Paneth cell-type carcinoma cells may be intimately related to such substance(s) in our case.     

Primary breast carcinomas with neuroendocrine features: Clinicopathological features and analysis of tumor growth patterns in 36 cases

Primary breast carcinoma with neuroendocrine features (NEBC) is an uncommon tumor. In the classification of WHO 2012, these tumors were categorized as: 1- neuroendocrine tumor, well-differentiated; 2- neuroendocrine carcinoma, poorly differentiated/small cell carcinoma; and 3- invasive breast carcinoma with neuroendocrine differentiation. In this study, we reviewed NEBC except poorly differentiated/small cell carcinoma variant in order to define the morphological growth patterns and cytonuclear details of these tumors. All breast surgical excision materials between 2007 and 2016 were re-evaluated in terms of neuroendocrine differentiation. Thirty-six cases showing positive staining for synaptophysin and/or chromogranin A in ≥50% of tumor cells were included in the study. All cases were female with a mean age of 67.4. Mean tumor diameter was 26 mm. Multifocality was noted in 5 cases. Grossly, they were mostly infiltrative mass lesions. T stages, identified in 34 cases, were as follows: 13 cases with pT1; 19 pT2 and 2 pT3. We described schematically 4 types of patterns depending on predominant growth pattern, except one case: 1) Large-sized solid cohesive groups (6 cases), 2) Small- to medium-sized solid cohesive groups with trabeculae/ribbons and glandular structures (6 cases), 3) Mixed growth patterns (20 cases), 4) Invasive tumor with prominent extracellular and/or intracellular mucin (3 cases). The tumor cells were mostly polygonal-oval with eosinophilic/eosinophilic-granular cytoplasm. The nuclei of tumor cells were mostly round to oval with evenly distributed chromatin. Only 5 cases showed high grade nuclear and histological features. Molecular subtypes of the cases were as follows: 33 luminal A, 2 luminal B, and 1 triple negative. NEBC should come to mind when a tumor display one of the morphological patterns described above, composed of monotonous cells with mild to moderate nuclear pleomorphism and abundant eosinophilic/eosinophilic granular or clear cytoplasm, especially in elderly patients.     

Expression of novel neuroendocrine marker insulinoma-associated protein 1 (INSM1) in genitourinary high-grade neuroendocrine carcinomas: An immunohistochemical study with specificity analysis and comparison to chromogranin,synaptophysin, and CD56

Confirmation of genitourinary high-grade neuroendocrine carcinomas (GU-HGNECs) often requires immunohistochemical staining. Here we evaluated a novel neuroendocrine marker, insulinoma-associated protein 1 (INSM1), in GU-HGNECs with comparison to chromogranin, synaptophysin and CD56. Immunohistochemical expression of INSM1, chromogranin, synaptophysin, and CD56 was evaluated in 39 GU-HGNECs using full tissue sections [4 in kidney, 28 in urinary bladder, and 7 in prostate; 31 small cell carcinomas (SmCCs), 6 large cell neuroendocrine carcinomas (LCNECs), 2 mixed SmCC-LCNECs]. In 33 SmCCs/components, INSM1 showed similar sensitivity (93.9 %) to chromogranin (87.8 %), synaptophysin (93.9 %) and CD56 (87.8 %), and stained a similar percentage of tumor cells (52 %) to chromogranin (49 %) and CD56 (52 %), but lower than synaptophysin (87 %) (p < 0.0001). In 8 LCNECs/components, INSM1 is similar to chromogranin, synaptophysin or CD56 in sensitivity (62.5 %, 62.5 %, 75 %, 62.5 %, respectively) and the mean percentage of positively stained tumor cells (21 %, 44 %, 48 %, 37 %, respectively). INSM1 is more sensitive for SmCCs than LCNECs (93.9 % vs. 62.5 %, p = 0.015). INSM1 showed 97.4 % specificity upon analyzing 273 genitourinary non-neuroendocrine tumors on tissue microarrays. Our study indicates that INSM1 is a sensitive marker for genitourinary HGNECs with high specificity. For genitourinary SmCCs, INSM1 shows similar sensitivity to chromogranin, synaptophysin and CD56 but stains a lower percentage of tumor cells than synaptophysin. For genitourinary LCNECs, INSM1 showed similar sensitivity to chromogranin, synaptophysin and CD56. INSM1 is more sensitive for genitourinary SmCCs than LCNECs. Our result and literature review indicate that whether INSM1 is more sensitive than conventional neuroendocrine markers for HGNECs depends on the tumor primary sites.     

Primary pure large-cell neuroendocrine carcinoma of the ovary

We report a case of a 73-year-old female with a rare simultaneous occurrence of three tumors: ovarian carcinoma, endometrial carcinoma, and breast carcinoma. The ovarian tumor was a primary pure large-cell neuroendocrine carcinoma. Grossly, the left ovary was enlarged by a solid tumor that measured 9 x 7 x 7 cm. Histologically, the tumor consisted of large cells with irregular hyperchromatic nuclei and a moderate amount of eosinophilic cytoplasm. In some areas, the tumor cells were arranged in solid sheets; however, the predominant pattern was cribriform and solid-alveolar, with palisaded tumor cells located peripherally. The tumor cells showed multiple mitotic figures (up to 43 mitoses/10 HPF). Large areas of tumor necrosis were found. Immunohistochemically, the tumor cells were positive for EMA, synaptophysin, chromogranin, CD56, and CEA. Cytokeratin 20 was positive focally. Primary large-cell neuroendocrine carcinoma of the ovary is a rare tumor. To the best of our knowledge, only 4 cases of a pure tumor of this type have been reported to date.     

Ungewöhnliches neuroendokrines Karzinom des Ösophagus

We report a rare case of a neuroendocrine carcinoma located in the esophagus of a 62-year-old male patient. The initial diagnosis of a "small-cell tumor" was based on biopsy. Our diagnosis was based on the histomorphological examination of the resected material. Diagnostic criteria were the characteristic solid or clustered growth patterns, monomorphic cell nuclei, lack of necrosis, immunohistochemical detection of neuroendocrine markers like chromogranin, synaptophysin and neuron-specific enolase (NSE) as well as detection of cytoplasmic neuroendocrine granules by electron microscopy. In addition, we found an increased prolific activity by staining with Ki67 antigen. 30% of the cell nuclei displayed a positive reaction. Focal invasion of blood vessels was also detected. With 17 different chromosomal imbalances, comparative genomic hybridization (CGH) revealed a malignant tumor stage that was not visible at the microscopic level. According to the new WHO classification of neuroendocrine tumors the described tumor was identified as an intermediate between a well-differentiated neuroendocrine carcinoma and a low-differentiated neuroendocrine carcinoma.