Cytokeratin 20-positive large cell neuroendocrine carcinoma of the colon

Treatment indicators and prognostic factors in colorectal neuroendocrine neoplasms and adenocarcinoma with neuroendocrine differentiation: a single center retrospective study

PURPOSE

This study compared survival and metastasis occurrence between colorectal neuroendocrine neoplasms (cNEN) and colorectal adenocarcinoma with neuroendocrine differentiation (cNED) and further explored their prognostic factors and treatment indicators.

METHODS

Patients diagnosed as cNEN and cNED in West China Hospital from January 2009 to December 2020 were enrolled. The diagnosis and metastasis rates were calculated. Univariate and multivariate Cox analyses were conducted for progression-free survival (PFS) in cNEN surgical patients, and generalized linear regression was used for metastatic disease.

RESULT

The study enrolled 435 patients, including 257 neuroendocrine tumors (NET), 52 neuroendocrine carcinomas (NEC), 29 mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN), and 97 NED patients, of whom 202 received local resection, and 233 received radical resection. Metastasis rates were higher in MiNEN and NEC groups compared to other groups (NED: 28.9%, MiNEN: 58.6%, NEC: 65.4%, NET: 8.6%, p < 0.001). The liver is the main metastatic site in cNEN, whereas cNED metastasized to various sites. For NEC and MiNEN patients, colon location (p = 0.002) and T stage > 2 (p = 0.040) were associated with disease progression separately. Independent risk factors for metastatic NET included tumor grade G2/G3 (p < 0.001), colon location (p = 0.001), size ≥ 1 cm (p = 0.005), and CK20 partial positive (p < 0.001).

CONCLUSION

cNEN show high metastatic capacity and are challenging to diagnose. More aggressive treatment and follow-up strategies are necessary for those patients. NET tumor grade higher than G2, size larger than 1 cm, or located in the colon should be managed with radical surgery.

Silent advanced large cell neuroendocrine carcinoma with synchronous adenocarcinoma of the colon: A case report

BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) accounts for about 0.25% of colorectal cancer patients. Furthermore, synchronous LCNEC and adenocarcinoma coexistence in the colon is very rare. LCNEC are usually aggressive and have a poor prognosis. Usually, colorectal LCNEC patients complain of abdominal symptoms such as pain, diarrhea or hematochezia because it is often diagnosed as an advanced disease that accompanies metastatic lesions.

CASE SUMMARY

We describe a case of relatively asymptomatic synchronous LCNEC and colon adenocarcinoma. A 62-year-old male patient visited our hospital due to anemia detected by a local health check-up. He did not complain of melena, hematochezia or abdominal pain. Physical examination was unremarkable and his abdomen was soft, nontender and nondistended with no palpable mass. Laboratory tests revealed anemia with hemoglobin 5.1 g/dL. Colonoscopy revealed an ulcerofungating lesion in the ascending colon and about a 1.5 cm-sized large sessile polyp in the sigmoid colon. Endoscopic biopsy of the ascending colon lesion revealed the ulcerofungating mass that was LCNEC and endoscopic mucosal resection at the sigmoid colon lesion showed a large polypoid lesion that was adenocarcinoma. Multiple liver, lung, bone and lymph nodes metastasis was found on chest/abdominal computed tomography and positron emission tomography. The patient was diagnosed with advanced colorectal LCNEC with liver, lung, bone and lymph node metastasis (stage IV) and synchronous colonic adenocarcinoma metastasis. In this case, no specific symptom except anemia was observed despite the multiple metastases. The patient refused systemic chemotherapy and was discharged after transfusion.

CONCLUSION

We report a case of silent LCNEC of the colon despite the advanced state and synchronous adenocarcinoma.

A case of colorectal large cell neuroendocrine carcinoma accompanied by disseminated peritoneal leiomyomatosis

Background

Neuroendocrine carcinomas (NECs) of the colon are among the rarest types of colorectal cancers. Among these, large cell type neuroendocrine carcinoma (LCNEC) is particularly rare. Colorectal NEC is an aggressive disease, and there are few reports of long-term survivors. Here, we report a case of LCNEC accompanied by disseminated peritoneal leiomyomatosis that was difficult to diagnose.

Case presentation

The case involves a 62-year-old female found to be positive for fecal occult blood by medical examination. An endoscopy revealed a tumor in the ascending colon, and the biopsy revealed poorly differentiated cancer. Abnormal FDG accumulation with peritoneal thickening was visible on 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) and suspected to be peritoneal dissemination. Laparoscopic ileocecal resection was performed for the tumor of the ascending colon with abdominal wall invasion. At that time, numerous intra-abdominal nodules were observed, indicating peritoneal dissemination. The pathological diagnosis of the primary lesion was LCNEC, and the patient requested to undergo total peritoneal resection. After one course of chemotherapy with irinotecan plus cisplatin, she underwent total peritoneal resection, uterine annex resection, left inguinal lymph node resection, and intra-abdominal hyperthermic intraperitoneal chemotherapy with mitomycin C. Because a postoperative pathological examination revealed that the intra-abdominal nodules were leiomyomas, we diagnosed the patient with disseminated peritoneal leiomyomatosis. The left inguinal lymph node was diagnosed with a metastatic tumor. In summary, the final diagnosis was LCNEC in the ascending colon with inguinal lymph node metastasis. Postoperative chemotherapy has been administered to date. She is currently 18 months post-primary surgery and 15 months post-peritonectomy without apparent recurrence or metastatic findings.

Conclusion

We experienced a case of Stage IVa colorectal LCNEC accompanied by disseminated peritoneal leiomyomatosis. Although the prognosis is generally poor, multidisciplinary treatment for advanced colorectal LCNEC may result in a favorable outcome for some patients. If peritoneal dissemination is suspected during operation, sampling of the nodule to confirm the pathological diagnosis is advisable.

Mixed neuroendocrine-non-neuroendocrine neoplasms of ascending colon: A case report

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Colon MiNEN, in this case, adenocarcinoma and NET G1 is a rare tumor.

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Preoperative diagnosis of MiNEN is difficult, and detailed observation of histopathology is important.

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Prognosis depends on the more aggressive components of adenocarcinoma or NET.

Introduction

Neuroendocrine tumor (NET) that develops in the right-sided colon is relatively rare. Coexistence of adenocarcinoma and NET is extremely rare, and such cases are called mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN).

Presentation of case

Colonoscopy in an 85-year-old woman for an anemia examination indicated laterally spreading tumor-nongranular (LST-NG) in the transverse colon. Colonoscopy and endoscopic ultrasonography (EUS) showed that the depth of the tumor invasion was deep submucosal. The tumor localization was diagnosed as transverse colon close to the hepatic curvature by enema. Computed tomography (CT) showed no obvious lymph node or distant metastasis. Based on these findings, laparoscopic transverse colectomy with D2 lymphadenectomy was performed. Pathologically, most of the tumor was well-differentiated tubular adenocarcinoma, but some solid follicles of polygonal tumor cells with poor nuclear atypia were observed. Immunostaining was positive for synaptophysin and diagnosed as NET G1. This tumor consisted of adenocarcinoma and neuroendocrine tumor, so we diagnosed it as MiNEN and classified the tumor as fT1N0M0 fStage I (TNM Classification of Malignant Tumors, 8th Edition). Since it was an early stage cancer, postoperative adjuvant therapy was not performed. No recurrence has yet been noted.

Discussion

Although MiNEN is extremely rare, the detailed pathological specimen observation and diagnosis are important because long-term follow-up after surgery is needed, as is the adequate selection of postoperative adjuvant therapy.

Conclusion

It is important to elucidate the mechanisms involved in the coexistence of NET and adenocarcinoma and to apply these findings to future medical care.

Incidence and Survival Patterns of Rare Anal Canal Neoplasms Using the Surveillance Epidemiology and End Results Registry

Small cell, neuroendocrine tumors, and melanoma of the anus are rare. Limited data exist on the incidence and management for these rare tumors. A large, prospective, population-based database was used to determine incidence and survival patterns of rare anal neoplasms. The Surveillance, Epidemiology and End Results registry was queried to identify patients diagnosed with anal canal neoplasms. Incidence and survival patterns were evaluated with respect to age, sex, race, histology, stage, and therapy. We identified 7078 cases of anal canal neoplasms: melanoma (n = 149), neuroendocrine (n = 61), and small cell neuroendocrine (n = 26). Squamous cell carcinoma (SCC) (n = 6842) served as the comparison group. Anal melanoma (AM) demonstrated the lowest survival rate at 2.5 per cent. Neuroendocrine tumors (NETs) demonstrated similar survival as SCC (10-year survival for regional disease of 25 and 22.3%, respectively). Ten-year survival of small cell NETs resembled AM (5.3 vs 2.5%). Age 60 years or older, sex, black race, stage, and surgery were independent predictors of survival. This study presents the largest patient series of rare anal neoplasms. NETs of the anal canal demonstrate similar survival patterns to SCC, whereas small cell NETs more closely resemble AM. Accurate histologic diagnosis is vital to determine treatment and surgical management because survival patterns can differ among rare anal neoplasms.

Synchronous NET and colorectal cancer development: a case report

Background

The incidence of synchronous gastrointestinal neuroendocrine tumors (GI-NETs) and colorectal cancer is very low.

Case presentation

We present a 72-year-old man diagnosed with a rectal neuroendocrine tumor (NET) with multiple organ metastases and simultaneous sigmoid colon cancer. Although the NET was his prognostic factor, he underwent a laparoscopic sigmoidectomy at first because it was expected that the colon cancer would cause obstruction or bleeding during NET treatment. Subsequently, he started taking everolimus.

Conclusions

We should consider surgical resection of the synchronous cancer before systemic therapy for a GI-NET regardless of the difference in prognosis between synchronous tumors, if the cancer may impair the continuation of systemic therapy.

Neuroendocrine neoplasms of gastrointestinal tract and secondary primary synchronous tumors: A systematic review of case reports. Casualty or causality?

BACKGROUND

Neuroendocrine neoplasms (NENs) can arise in most of the epithelial organs of the body and are not a rare condition in the gastrointestinal tract (GIT). The presence of NENs in GIT associated with other secondary primary malignancies (SPM) has been considered an exotic event. This study aims to describe the case reports of NENs accompanied by synchronous primary tumors.

METHODS AND FINDINGS

We performed a systematic literature search of the databases Scopus, PubMed, Scielo and LILACS to identify case reports that described the presence of NENs in GIT with SPM. 78 case reports were included. The mean of age of the cases was 60.2 years. 60% were male. 95.4% were NENs G1. 17 cases of NENs had metastasis. 80% of SPM were recognized in the GIT (36% in stomach, 27% in large intestine, 11.2% in small intestine, and 5.6% in esophagus). The most common type of SPM was adenocarcinoma (49.4%), followed by GIST (13.5%), other NENs in different GIT segment (7.9%), lymphoma (6.8%), and squamous cell carcinoma (4.5%). The most common tumor in GIT was adenocarcinoma (97.6%) and the presence of adenocarcinoma in the same segment of GIT was found in 68.4% of the cases. Association between adenocarcinomas and NENs in GIT (p:<0.0001) and adenocarcinoma and tumor in the same segment of GIT location were observed (p<0.001).

CONCLUSION

These results demonstrate that NENs with SPM are not a rare condition. Several theories have been proposed to explain this association; one of these is the ability of NENs to generate synchronous tumors by autocrine and paracrine effect. We observed an association between adenocarcinomas and NENs in the same segment of GIT.

Gastrointestinal Neuroendocrine Tumor, Colon Adenocarcinoma, and Hyperparathyroidism: An Unorthodox Synchronism

Synchrony of colorectal adenocarcinoma with neuroendocrine tumor (NET) and hyperparathyroidism with colon adenocarcinoma is a rare entity, reported in a handful of cases. We authors would like to report a rare case of coexistence of poorly differentiated colon adenocarcinoma, NET of appendix and hyperparathyroidism. A 43-year-old Caucasian female was diagnosed with metastatic colon adenocarcinoma involving the caecum and appendiceal orifice. The resected specimen also confirmed presence of concurrent well-differentiated NET in distal half of appendix. For this patient, serum chemistry was significant for severe hypercalcemia with elevated parathyroid hormone and fairly normal range parathyroid hormone-related peptide. Importantly, association among the aforementioned conditions remains elusive and warrants further research; nevertheless, surveillance procedures could be performed in patients, if a correlation exists at all.

Mixed Neuroendocrine Carcinoma and Squamous Cell Carcinoma of the Colon: Case Report and Literature Review

Neuroendocrine carcinoma (NEC) of the colon is very rare, and squamous cell carcinoma (SCC) of colon cancer is rare. We recently treated a patient with both NEC and SCC that initially presented as multiple unresectable liver and lung metastases. A 68-year-old Japanese man was referred to our hospital because of diarrhea with descending colon cancer obstruction. He underwent a left colectomy. Based on immunohistochemistry results, we diagnosed mixed NEC and SCC, the primary lesion location of which was probably the lung in the final pathologic examination. He began systemic palliative chemotherapy with CDDP and CPT-11. After 3 months of treatment, shown the progressive disease, we started CDDP and VP-16. The patient was not eligible for additional chemotherapy after 2 months.

Rapamycin Treatment for Benign Multicystic Peritoneal Mesothelioma: A Rare Disease with a Difficult Management

BACKGROUND Benign multicystic peritoneal mesothelioma (BMPM) is a rare intra-abdominal tumor. Although considered by many to be benign, this tumor has a high local recurrence rate. Because of its rarity, preoperative diagnosis is difficult and its origin and pathogenesis are uncertain. There are no evidence-based treatment strategies for BMPM. It is agreed that the best treatment strategy for BMPM is the combination of surgical cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). An increasing body of evidence supports a pivotal role of the cytoplasmic serine/threonine kinase mTOR in the development and progression of several neoplastic diseases and specific mTOR inhibitors, including rapamycin, have been suggested as potential therapeutic options for different cancers. CASE REPORT A 65-year-old male with end-stage renal disease on hemodialysis for seven years presented with BMPM. He underwent surgery to remove multiple peritoneal cysts, but four months later he experienced a recurrence of the disease. Immunohistochemistry of the cysts demonstrated a high level of phosphorylation of p70S6 kinase, a downstream mTOR target, and since a target therapy that blocks PI3K/Akt/mTOR pathway has been shown to have a scientific and logical rationale to treat this rare intra-abdominal neoplasia, we started the patient on low dose rapamycin therapy, an mTOR inhibitor. Long-term mTOR inhibition resulted in a complete and stable remission of BMPM. CONCLUSIONS The current case is the first report of BMPM successfully treated with rapamycin, which resulted in a long-lasting response to mTOR inhibition.

Clinical and pathological characteristics and prognosis of rectal neuroendocrine tumors

AIM

To analyze the clinical and pathological features and prognosis of rectal neuroendocrine neoplasms (NENs) to improve the diagnosis and treatment of this disease and reduce its misdiagnosis and missed diagnosis.

METHODS

We collected the clinical data of 84 patients with rectal NENs, who were diagnosed by endoscopic biopsy or surgical pathologic examination at the First Affiliated Hospital of Zhengzhou University from April 2012 to April 2015. The clinical manifestations, pathological manifestations, diagnosis, treatment and prognosis were analyzed.

RESULTS

The average age of the 84 patients was 48.8 ± 13.4 years (range 21-70, years), and there were 52 (61.9%) males. Main symptoms were bowel habit change, gastrointestinal bleeding and abdominal pain, and there was no carcinoid syndrome. Pathological grading results were: G1 in 40 (47.6%) cases, G2 in 40 (47.6%), and G3 in 4 (4.8%). With regard to immunohistochemical markers, all cases were positive for Syn, 58 (69.0%) cases were positive for CgA, and 36 (42.9%) positive for NSE. Of all the patients, 20 were treated by endoscopic therapy, 56 treated by surgery, and 8 by palliative care. Twelve (14.3%) cases developed metastases, including lymph node metastasis in eight cases and liver metastasis in four cases. The median follow-up period was 16 mo (3-32 mo). During follow-up, four cases recurred and eight cases died.

CONCLUSION

Rectal NENs are a group of low grade malignant tumors with atypical clinical manifestations and relatively good prognosis. The awareness of rectal NENs should be improved. Suspicious lesions that cannot be diagnosed by endoscopic biopsy should be subject to pathological examination as early as possible to reduce the misdiagnosis and missed diagnosis.

Synchronous adenocarcinoma and neuroendocrine carcinoma of the colon: a case report

Neuroendocrine tumors (NETs) originating from the gastrointestinal tract are considered to be relatively rare tumors with a poor prognosis. We describe a case of an 83-year-old male who presented with complains of bleeding per rectum. Colonoscopy revealed two ulceroproliferative tumors, one in the sigmoid colon and another in the descending colon. The patient underwent left hemicolectomy. Based on the immunohistochemistry, the sigmoid colon tumor was diagnosed as well-differentiated adenocarcinoma, whereas the descending colon tumor was diagnosed as NET. NET coexisted with adenocarcinoma occurring separately in the same segment of colon, as in the present case, is distinctly rare and has not been reported earlier. The coexistence of the NETs with other primary malignancies has been increasingly recognized. Therefore, we recommend that the patients with the diagnosis of NETs should undergo further screening for the associated primary malignancies to prevent late-stage diagnosis of synchronous malignancies.

Synchronous Small Cell Neuroendocrine Carcinoma and Adenocarcinoma of the Colon: A Link for Common Stem Cell Origin?

Synchronous carcinomas have been recognized for over a century, with synchronous primary adenocarcinoma of the colon reported to range from 2-11% of cases involving this type of malignancy. Small cell carcinomas occur frequently with colorectal adenomas; however, despite these reports and a known adenoma-to-carcinoma sequence, scarce literature exists on synchronous colorectal adenocarcinoma and small cell carcinomas. We present a rare cancer of synchronous small cell neuroendocrine carcinomas and discuss a possible link between these two cancers.

Colorectal poorly differentiated neuroendocrine carcinomas and mixed adenoneuroendocrine carcinomas: insights into the diagnostic immunophenotype, assessment of methylation profile, and search for prognostic markers

Colorectal poorly differentiated neuroendocrine carcinomas (NECs) and mixed adenoneuroendocrine carcinomas (MANECs) are well-recognized entities generally known to be associated with biological aggressiveness and poor patient survival. However, a few published papers have highlighted the existence of a subgroup of tumors with a better survival than expected; however, to date, there are no established parameters that usefully identify this category. In the present study we have investigated the morphologic features, the CpG methylator phenotype (CIMP), microsatellite instability (MSI), and the immunohistochemical profile, including the expression of transcription factors (TTF1, ASH1, CDX2, and PAX5), stem cell markers (CD117 and CD34), and cytokeratins 7 and 20, in a series of 39 carcinomas (27 NECs and 12 MANECs) to better characterize such neoplasms and to search for prognostic indicators. No different patient survival was observed between NECs and MANECs. Neoplasms showed a heterogenous spectrum of morphologic and immunohistochemical features; however, only large-cell subtype, significant peritumoral lymphoid reaction, CD117 immunoreactivity, vascular invasion, and MSI/CIMP+ status were significantly correlated with prognosis on univariable analysis. Furthermore, vascular invasion and CD117 immunoreactivity were independent prognostic markers on multivariable analysis. In addition to these prognostic features, neoplasms showed different expression of transcription factors, stem cell markers, and cytokeratins that should be considered for diagnostic purposes and, especially, for discriminating among possible differential diagnoses.

CK20 Positive Large-cell Neuroendocrine Carcinoma Presenting with Skin Metastases

We present a case of cytokeratin (CK) 20-positive large cell neuroendocrine carcinoma (LCNEC) presenting with multiple skin metastases as the primary manifestation. The patient was a 55-year-old man who presented with a one- month history of subcutaneous skin colored nodules of various sizes on his trunk. Pathologic examination of the skin revealed a nested and solid proliferation of large undifferentiated cells with vesicular nuclei and prominent nucleoli. Tumor cells were found to be immunohistochemically positive for CK 20, chromogranin A, synaptophysin, and CD56. Based on these features, the tumor was diagnosed as a large cell neuroendocrine carcinoma with multiple skin metastases. Computed tomographic (CT) imaging found metastatic foci in the liver, pleura, bone, and lymph nodes. We were unable to identify the primary site of origin. To the best of our knowledge, this is the first case of a large cell neuroendocrine carcinoma with a primary manifestation of multiple skin metastases.

Concurrent large cell neuroendocrine carcinoma and adenocarcinoma of the ascending colon: a case report

Large cell neuroendocrine carcinomas of the colon are rare and represent only a small percentage of all colonic endocrine tumors. Here, we report a case of a colonic large cell neuroendocrine carcinomas concurrent with a colonic adenocarcinoma. A 70-year-old man presented with acute abdominal pain. A spiral computed tomography scan of the abdomen revealed eccentric wall thickening on the ascending colon. An explorative laparotomy and a right hemicolectomy were performed. Grossly, two separated masses were observed in the proximal ascending colon. One was a 7.4 × 5.1 cm ulcerative fungating lesion, and the other was a 2.8 × 1.9 cm polypoid lesion. Microscopically, the ulcerative fungating lesion showed a well-differentiated neuroendocrine morphology with necrosis and increased mitosis. Most of the tumor cells had large, vesicular nuclei with eosinophilic nucleoli, variable amounts of eosinophilic cytoplasm, and immunoreactivity for chromogranin A and synaptophysin. The polypoid lesion was a well-differentiated adenocarcinoma that had invaded the submucosa. We diagnosed these lesions as a concurrent large cell neuroendocrine carcinoma and an adenocarcinoma of the ascending colon.

Pathologic research update of colorectal neuroendocrine tumors

Colorectal neuroendocrine tumors (NETs) originate from neuroendocrine cells in the intestinal tract, and represent a small area within oncology, but one which has provided increasing new data during the past years. Although the World Health Organization has determined clinical and histological features to predict prognosis for such tumors, they may not be valid on an individual basis. We aim to give an overview of the recent findings with regard to pathology, molecular genetics and diagnosis of NETs.

Synchronous large-cell neuroendocrine carcinoma and adenocarcinoma of the colon

Large-cell neuroendocrine carcinoma of the colon is a rare entity with a prognosis that is usually poor due to the high likelihood of early metastasis. A 61-year-old man had surgery for colon cancer of the transverse colon and cecum. Microscopic examination of the tumor showed that the location was the proximal transverse colon, with small nests containing rosettes and palisading patterns of large tumor cells with faintly granular cytoplasm. The immunohistochemistry was positive for synaptophysin and chromogranins. The tumors were diagnosed as a large-cell neuroendocrine carcinoma of the colon. In addition, the tumor of the cecum showed microscopic findings consistent with a well-differentiated adenocarcinoma. The immunohistochemical panel showed that the tumor was negative for neuroendocrine markers. There were no clinical findings suggestive of hormone hypersecretion. Cancer metastasis was found in the peritoneum section of the small bowel. Postoperative chemotherapy was applied. The patient was alive with good performance after, and there was no sign of tumor progression. This is the first case of a synchronous large-cell neuroendocrine carcinoma and adenocarcinoma of the colon. The patient was treated successfully with debulking surgery and systemic chemotherapy.

Large-cell neuroendocrine carcinoma of the ampulla of Vater

Large-cell neuroendocrine carcinoma is a high-grade neuroendocrine carcinoma, originally described in the lung. The tumor rarely occurs in extrapulmonary sites like the gastrointestinal tract, and only few examples have been described in the ampulla of Vater. A new case of large-cell neuroendocrine carcinoma of the ampulla of Vater in a 60-year-old man is reported. After pancreatoduodenectomy, macroscopic examination revealed ulcerated tumor in the region of the ampulla of Vater. Microscopically, the tumor exhibited organoid, predominantly nested growth pattern, consisting of large, polygonal cells with pleomorphic nuclei. Average number of mitoses was 36 per 10 high-power fields. Small and large areas of necrosis were identified. Immunohistochemically, the tumor cells were positive for synaptophysin, chromogranin A, PGP 9.5, neuron-specific enolase, pancytokeratin, CK8 and somatostatin and negative for CK7, CK20, S-100, TTF-1, HMB-45, CD117, E-cadherin and regulatory peptides. Ki-67 proliferative index was 41%. Histone deacetylase (HDAC) analysis showed almost identical results for HDAC1, HDAC2 and HDAC3--60, 60.3 and 61%, respectively. Two months after surgery, liver metastases occurred, confirming highly aggressive behavior of large-cell neuroendocrine carcinoma.

[A case of large cell neuroendocrine carcinoma of the colon]

Neuroendocrine carcinoma of the colon can be classified into small cell carcinoma and large cell neuroendocrine carcinoma. The incidence of neuroendocrine carcinoma is so low that the guidelines for the treatment of large cell neuroendocrine carcinoma of the colon are not established. The prognosis of large cell neuroendocrine carcinoma of the colon is worse than that of conventional adenocarcinoma of the colon. We report a case of large cell neuroendocrine carcinoma of the colon that treated with right hemicolectomy and 6th sequential combination chemotherapy of 5-fluorouracil and cisplatin. There has been no evidence of the recurrence of metastasis of tumor for 6 months.

A case of cytokeratin 20-positive large-cell neuroendocrine carcinoma of the breast

We report a rare case of large-cell neuroendocrine carcinoma of the breast. A 63-year-old woman was admitted to our hospital with a firm mass in the right breast. Mammography revealed a high-density mass with specula, and ultrasonography showed a heterogeneous hypoechoic mass with irregular margin and posterior acoustical shadowing. She underwent breast-conserving surgery with axillary lymph node dissection. Histopathologically, the tumor consisted of large cells with polygonal and prominent nuclei and a small amount of eosinophilic cytoplasm, and these cells showed palisading arrangement with fibrous stroma. The tumor cells were positive for neuroendocrine markers such as NSE, synaptophysin, CD56 (NCAM), but not for chromogranin A. Interestingly, the tumor cells showed reactivity for cytokeratin 20 but not for cytokeratin 7. The immunostaining pattern is different from the usual adenocarcinoma of the breast. The patient received postoperative radiotherapy and was given adjuvant chemotherapy. She has remained disease-free for 44 months.

Is nonsmall cell type high-grade neuroendocrine carcinoma of the tubular gastrointestinal tract a distinct disease entity?

Although small cell carcinoma of the gastrointestinal (GI) tract is well-recognized, nonsmall cell type high-grade neuroendocrine carcinoma (HGNEC) of this site remains undefined. At the current time, neither the World Health Organization nor American Joint Committee on Cancer includes this condition in the histologic classifications, and consequently it is being diagnosed and treated inconsistently. In this study, we aimed at delineating the histologic and immunophenotypical spectrum of HGNECs of the GI tract with emphasis on histologic subtypes. Guided primarily by the World Health Organization/International Association for the Study of Lung Cancer criteria for pulmonary neuroendocrine tumors, we were able to classify 87 high-grade GI tract tumors that initially carried a diagnosis of either poorly differentiated carcinoma with or without any neuroendocrine characteristics, small cell carcinoma, or combined adenocarcinoma-neuroendocrine carcinoma into the following 4 categories. The first was small cell carcinoma (n=23), which had features typical of pulmonary small cell carcinoma, although the cells tended to have a more round nuclear contour. The second was large cell neuroendocrine carcinoma (n=31), which had a morphology similar to its pulmonary counterpart and showed positive immunoreactivity for either chromogranin (71%) or synaptophysin (94%) or both. The third was mixed neuroendocrine carcinoma (n=11), which had intermediate histologic features (eg, cells with an increased nuclear/cytoplasmic ratio but with apparent nucleoli), and positive immunoreactivity for at least 1 neuroendocrine marker. The fourth was poorly differentiated adenocarcinoma (n=17). In addition, 5 of the 87 tumors showed either nonsmall cell type neuroendocrine morphology (n=3) or immunohistochemical reactivity for neuroendocrine markers (n=2), but not both. Further analysis showed that most HGNECs arising in the squamous lined parts (esophagus and anal canal) were small cell type (78%), whereas most involving the glandular mucosa were large cell (53%) or mixed (82%) type; associated adenocarcinomas were more frequent in large cell (61%) or mixed (36%) type than in small cell type (26%); and focal intracytoplasmic mucin was seen only in large cell or mixed type. As a group, the 2-year disease-specific survival for patients with HGNEC was 25.4% (median follow-up time, 11.3 mo). No significant survival difference was observed among the different histologic subtypes. In conclusion, our study demonstrates the existence of both small cell and nonsmall cell types of HGNEC in the GI tract, and provides a detailed illustration of their morphologic spectrum. There are differences in certain pathologic features between small cell and nonsmall cell types, whereas the differences between the subtypes of nonsmall cell category (large cell versus mixed) are less distinct. Given the current uncertainty as to whether large cell neuroendocrine carcinoma is as chemosensitive as small cell carcinoma even in the lung, our data provide further evidence in favor of a dichotomous classification scheme (small cell vs. nonsmall cell) for HGNEC of the GI tract. Separation of nonsmall cell type into large cell and mixed subtypes may not be necessary. These tumors are clinically aggressive. Prospective studies using defined diagnostic criteria are needed to determine their biologic characteristics and optimal management.

Poorly differentiated tumours of the anal canal: a diagnostic strategy for the surgical pathologist

Poorly differentiated malignancies affecting the anal canal are uncommon but pose diagnostic difficulties because of the wide range of normal cell types that may occur within a limited anatomical region. The range of lesions that may present as poorly differentiated tumours includes squamous cell carcinoma, adenocarcinoma, small and large cell neuroendocrine carcinoma, neuroendocrine carcinoma expressing epithelial cytokeratins and other patterns of mixed differentiation, undifferentiated carcinoma, malignant melanoma, lymphoma and secondary tumours. This review discusses the differential diagnosis of these neoplasms with the aid of short illustrative case studies.

Cytokeratins 7 and 20 immunoexpression profile in goblet cell and classical carcinoids of appendix

Goblet cell carcinoid (GCC) of the vermiform appendix is an uncommon neoplasm and its histogenesis is controversial. Whether GCC represents a morphological variant of classical appendiceal carcinoid or a mucin-producing adenocarcinoma is still conjectural. Little is known about the immunohistochemical expression of cytokeratins 7 (CK7) and 20 (CK20) in appendiceal neuroendocrine tumors. In this study, we compared the expression of CK7 and CK20 in 17 cases of appendiceal GCC and 25 cases of classical carcinoid. The tumors were also evaluated for Ki-67 proliferation index, mitotic activity, tumor necrosis, extracellular pools of mucin, obvious intestinal type adenocarcinomatous foci, angiolymphatic permeation, perineural/neural infiltration, and the depth of invasion of the appendix wall. Mesoappendiceal extension was present in 14 of 17 (82.3%) cases of GCC, whereas angiolymphatic and perineural/intraaneural involvement were found in 10 of 17 (58.8%) and 14 of 17 (82.3%) cases, respectively. The mitotic count ranged from 0 per 10 high power fields to 6 per 10 high power fields, with an average of 1.4 per 10 high power fields. Necrosis was not seen in any case and pools of extravasated mucin were present in 5 of 17 (29.4%) cases. Immunohistochemically, all 17 (100%) of GCC exhibited strong and diffuse immunopositivity for CK20, whereas expression of CK7 was present in 12 cases (70.5%), ranging from 5 to 50% of tumor cells being labeled. The Ki-67 labeling index ranged from 0 to 75% and showed no correlation to mitotic activity, angiolymphatic invasion or perineural/intraneural permeation. On the other hand, 25 cases of classical carcinoid tumors were consistently negative for CK7; however, 4 cases (16%) showed immunolabeling for CK20 in 25-50% of the tumor cells. The Ki-67 labeling index in classical carcinoids ranged from 0 to 5%. This study shows that in addition to the morphological differences, GCC (CK7/CK20-positive) and classical carcinoid (CK7/CK20-negative) differ in their expression of CK7 and CK20. In addition, GCC shows the same CK7/CK20 immunoexpression as colorectal adenocarcinoma. Goblet cell carcinoid should be regarded as a crypt cell or an amphicrine carcinoma rather than a variant of carcinoid tumor, a lesion that has benign connotations.

Composite adenocarcinoma and large cell neuroendocrine carcinoma of the rectum

Composite glandular-endocrine tumors of the gastrointestinal tract are rare neoplasms. Even more uncommon are the so-called amphicrine tumors, lesions in which dual epithelial and endocrine differentiation occurs in the same cell. We describe a patient who complained of rectal pain and bleeding with a mixed or composite adenocarcinoma and neuroendocrine carcinoma of the rectum. Histological examination revealed a distinct adenocarcinoma of conventional type with glandular structures admixed intimately with a neuroendocrine carcinoma. The latter component was deeply infiltrative, while the adenocarcinoma occupied the more superficial aspect of the tumor. What was interesting was the immunophenotype of the lesion: cytokeratin (CK) 20 expression was very focal in the adenocarcinoma component and negative in the neuroendocrine carcinoma, while CK 7 was expressed strongly in the adenocarcinoma and only focally in the neuroendocrine component. This cytokeratin profile suggests a possible origin from the anal transitional zone.