Neuroendocrine neoplasms of the lung

Systemic Treatment of Gastroenteropancreatic Neuroendocrine Carcinoma

OPINION STATEMENT

Treatment recommendations for advanced gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are based on uncontrolled, mainly retrospective data. Chemotherapy can offer palliative relief, but long-lasting complete responses or cures are rare. The European Neuroendocrine Tumour Society (ENETS) and European Society for Medical Oncology (ESMO) recommend platinum-based chemotherapy as first-line treatment. This has been the golden standard since the late 1980s and has been evaluated in mostly retrospective clinical studies. However, progression is inevitable for most patients. Unfortunately, data on effective second-line treatment options are scant, and ENETS and ESMO recommendations propose fluorouracil- or temozolomide-based chemotherapy schedules. As such, there is a huge unmet need for improved care. Improved knowledge on GEP-NEC biology may provide a pathway towards more effective interventions including chemotherapy, targeted gene therapy, peptide receptor radionuclide therapy, as well as immune checkpoint inhibitors. The review summarises this current state of the art as well as the most promising developments for systemic therapy in GEP-NEC patients.

[Resection concepts for early stage neuroendocrine tumors of the lungs and bronchi]

BACKGROUND

Neuroendocrine tumors of the lungs are a very inhomogeneous group of malignancies. The surgical treatment should be adapted to the anatomical localization and histological subtype and individualized according to the functional reserve.

MATERIAL AND METHODS

We performed a selective review of current literature, which was supplemented by personal experiences.

RESULTS

The currently available outcome data are very inhomogeneous and depend on the histological subtype of neuroendocrine pulmonary tumors. A radical R0 resection is the key for an improvement in long-term overall and disease-free survival.

CONCLUSION

Surgical treatment of carcinoid tumors is the current standard therapy. Sleeve resection should be performed, whenever possible. More aggressive tumors, such as large cell neuroendocrine carcinoma and small cell lung cancer should be treated in a multimodal concept.

Paraneoplastic Cushing syndrome, case-series and review of the literature

OBJECTIVES

Paraneoplastic Cushing syndrome is a rare condition, representing a small fraction of the adrenocorticotropic hormone (ACTH)-dependent cases of Cushing syndrome Methods: Four case descriptions and literature review, highlighting the diagnostic challenges and treatment options are presented.

RESULTS

Different tumor types can be associated with ectopic ACTH secretion. The most common types are bronchial carcinoids and small cell lung carcinoma (SCLC). However, in approximately 10 to 20% of the cases, no overt tumor (occult tumor) can be found. The diagnosis is made in a multistep process. Firstly, hypercortisolemia and adrenocorticotropin hormone dependency have to be confirmed. Distinction between a pituitary or ectopic cause can be cumbersome. MRI of the pituitary gland, a corticotropin releasing hormone stimulation test and a sinus petrosus sampling can be used. Treatment options consist of tumor management, somatostatin analogs, steroidogenesis inhibitors, and bilateral adrenalectomy.

CONCLUSION

Clinicians should consider the diagnosis, and opt for specific treatment, especially in patients with a history of neuroendocrine tumors.

Well-Differentiated Neuroendocrine Carcinoma of the Lung: A Clinicopathologic and Ultrastructural Study of 10 Cases

The clinico-pathologic characteristics of 10 resected pulmonary tumors, which proved to be well-differentiated neuroendocrine carcinomas (WDNC) on the basis of light microscopic, immunocytochemical, ultrastructural and immunoelectron microscopic investigations, were evaluated. The tumors showed a wide spectrum of histologic features that could be referred to three basic patterns: 1) a carcinoid-like pattern; 2) an organoid pattern characterized by palisading cells at the edge of cellular areas, and 3) a prevalent adenocarcinoma-like pattern. The second pattern was the most distinct even though it often mimicked the small cell/large cell subtype of small cell carcinoma (SCC) owing to its association with marked atypia and poor differentiation. All but one of the patients were males and smokers. The mean age was 58 years. Half of the tumors were centrally located including those showing the adenocarcinoma-like pattern. Disease-free and overall survival and type of tumor dissemination in four patients were similar to those of SCC. Five evaluable patients were alive and disease-free after a mean follow-up of 74 months. Two of these were initially diagnosed as SCC. We conclude that, because of its impact on prognosis, the diagnosis of WDNC appears to be relevant although other factors able to adversely affect the clinical course remain undefined.

[Metastatic bronchial carcinoid tumors]

Bronchial carcinoids are uncommon pulmonary neoplasms and represent 1 to 2 % of all lung tumors. In early stage of disease, the mainstay and only curative treatment is surgery. Bronchial carcinoids are generally regarded as low-grade carcinomas and metastatic dissemination is unusual. The management of the metastatic stage is not currently standardized due to a lack of relevant studies. As bronchial carcinoids and in particular their metastatic forms are rare, we apply treatment strategies that have been evaluated in gastrointestinal and pancreatic neuroendocrine tumors. However, bronchial carcinoids have their own characteristic. A specific therapeutic feature of these metastatic tumors is that they require a dual approach: both anti-secretory for the carcinoid syndrome, and anti-tumoral.

Clinical presentation and evaluation of neuroendocrine tumors of the lung

Neuroendocrine tumors of the lung encompass a wide spectrum. A carcinoid tumor is either a central smooth endobronchial tumor or a round, well-circumscribed, peripheral parenchymal lesion. Distinguishing typical carcinoid tumors from atypical carcinoid tumors is unreliable from a limited biopsy but can be based on age, presentation, and node enlargement. Large cell neuroendocrine cancer presents similarly to most non-small cell lung cancers. Small cell lung cancer has a characteristic presentation, with a rapid progression of symptoms, and a bulky central and/or mediastinal tumor. A diagnosis is achieved by limited biopsy and is usually reliable.

Roentgenological occult large-cell neuroendocrine carcinoma: Report of a long-term survivor

A 64-year-old male patient complained of a one-month history of bloody sputum. A polypoid tumor was almost obstructing the orifice of the subsegmental bronchus (B8b) of the anterior basal segment of the right lower lobe on bronchoscopy. Biopsy specimens of the tumor surface yielded a diagnosis of undifferentiated carcinoma. Clinical staging was T1aN0M0, stage IA. Surgical resection that comprised a right upper lobectomy with systematic mediastinal and hilar lymph node dissection was performed. Histopathologically, the tumor specimen was compatible with large-cell neuroendocrine carcinoma (LCNEC) of the subsegmental bronchus. Pathological staging was T1aN0M0, stage IA. To our knowledge, few cases of central-type LCNEC have been reported in the English literature, and ours is the first report of roentgenological occult LCNEC.

[Multidetector computed tomography assessment of the degree of differentiation of bronchial carcinoid tumors]

OBJECTIVE

To define the CT findings for bronchial carcinoid tumors and to determine whether these findings enable these tumors to be classified as typical or atypical.

MATERIAL AND METHODS

We reviewed the chest CT studies performed between 1 January 2001 and 31 December 2009 in patients at our hospital diagnosed with bronchial carcinoid tumors. The sample consisted of 52 patients (23 women and 29 men) with a mean age of 47 years (range 11-77 years). The 52 cases were classified as typical or atypical on the basis of the following radiological findings: size, location, focality, type of growth, calcifications, signs secondary to bronchial obstruction, and the presence of significant lymph node enlargement or metastases. These findings were then compared with the histological findings.

RESULTS

Typical carcinoid tumors were the most prevalent (46 cases). The variables associated with atypical tumors were: male sex, advanced age at onset, and size >3cm. The accuracy of CT in classifying atypical tumors correctly increased with the number of variables indicative of atypical carcinoid tumors. A negative result for atypical nature made it possible to rule out an atypical carcinoid tumor in 95% of the cases.

CONCLUSION

CT is useful for defining and characterizing carcinoid tumors into typical or atypical, although a precise formula for differentiating between the two types remains to be defined.

Neoadjuvant and adjuvant chemotherapy in resected pulmonary large cell neuroendocrine carcinomas: a single institution experience

BACKGROUND

Pulmonary large cell neuroendocrine carcinomas (LCNEC) are aggressive neoplasms with poor prognosis. The role of neoadjuvant and adjuvant therapies in these tumors remains uncertain.

METHODS

We performed a retrospective review of a prospective database. Kaplan-Meier estimates of overall survival (OS) were determined and compared across prognostic factors using log-rank analysis and the Cox proportional hazards model.

RESULTS

One hundred patients with resected LCNEC were identified from 1992 to 2008. Of these, 54% were male and 98% current or former smokers (mean 60.3 pack-years). Twenty-two patients received neoadjuvant platinum chemotherapy with a response rate of 68% (15 of 22). Eighty percent (80 of 100) underwent lobectomy and 11% (11 of 100) pneumonectomy with a 90% (90 of 100) complete resection (R0) rate. Seventy-one percent (71 of 100) were stage I-II, and 20 of 71 received platinum adjuvant chemotherapy. Mean OS was 40 months. Univariate factors associated with decreased OS included male gender (p = 0.007), increasing tumor (T) stage (p = 0.004), and stage III-IV disease (p = 0.04). Stage IB patients fared significantly worse than IA (p = 0.006). Multivariate analyses identified male gender (hazard ratio [HR] 2.3, p = 0.007), comorbid pulmonary disease (HR 2.3, p = 0.012), and pathologic stage (HR = 2.2, p = 0.011) as associated with risk of death. Univariate analysis in stage IB-IIIA completely resected (R0) patients receiving combination platinum-based induction and (or) adjuvant chemotherapy showed a trend toward improved OS (median survival 7.4 vs 2 years, p = 0.052).

CONCLUSIONS

The LCNEC has a high response rate to platinum-based neoadjuvant chemotherapy. Resected advanced-stage patients receiving combination neoadjuvant and (or) adjuvant chemotherapy may have a survival advantage. These therapies should be considered in resectable patients with LCNEC.

Behaviour and survival of high-grade neuroendocrine carcinomas of the lung

INTRODUCTION

Large-cell neuroendocrine carcinoma is an aggressive variant of large-cell carcinoma of the lung, which has poor survival in most series, resembling that of small-cell lung carcinoma. We report our retrospective assessment of surgically-resected cases of both tumours.

METHODS

33 large-cell neuroendocrine carcinomas and 16 peripheral small-cell lung carcinomas were reassessed retrospectively. Survival rates of both tumours in surgically-resected cases were calculated and compared using Kaplan-Meier survival curves and Log Rank test, respectively.

RESULTS

In large-cell neuroendocrine carcinomas, there were 25 patients with pathologic stage I, 4 with pathologic stage II and 4 with pathologic stage III. In small-cell lung carcinomas, there were 6 patients with pathologic stage I, 3 with pathologic stage II and 7 with pathologic stage III. 12% of large-cell neuroendocrine carcinomas and 62.5% of small-cell lung carcinomas were of advanced disease. The mean follow-up was 89 months. The actuarial survival for the 2 groups was not significantly different.

CONCLUSION

Large-cell neuroendocrine carcinomas of the lung have poor prognosis even in early stages, with survival rates similar to that of small-cell lung carcinomas.

Pulmonary neuroendocrine neoplasms: a review of clinicopathologic and cytologic features

Neuroendocrine tumors form a distinct group of lung neoplasms sharing characteristic cytohistologic, immunohistochemical, ultrastructural, and molecular features. The objective of this review article is to discuss the diagnostic classifications and the morphologic cytologic-histologic features for the different categories of neuroendocrine tumors of the lung. An accurate characterization of the neuroendocrine tumors of the lung requires knowledge of specific criteria separating the major categories, which is highly essential for determining prognosis and treatment options for these patients.

Spectrum of pulmonary neuroendocrine cell proliferation: diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids

OBJECTIVE

The objectives of this article are to review the radiologic, pathologic, and clinical features of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids and to discuss the possible role of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and tumorlet in the development of carcinoids.

CONCLUSION

Given the potential significant morbidity of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and its neoplastic counterparts, it is important to understand and recognize these disease entities. A conceptual continuum of these neuroendocrine entities is suggested.

Pulmonary large cell neuroendocrine carcinoma: its place in the spectrum of pulmonary carcinoma

In 1999, the World Health Organization categorized large cell neuroendocrine carcinoma (LCNEC) as a variant of large cell carcinoma. The World Health Organization categorization not only classified histologic types of large cell carcinomas of the lung in detail, but also revealed that histologic subtypes of lung carcinomas were closely related to the prognosis of patients with those carcinomas. Large cell neuroendocrine carcinomas are common tumors that are now more frequently diagnosed by pathologists as recognition of LCNEC improves. Since the first report of LCNEC in 1991, many authors have reported that LCNECs are aggressive tumors and that patients with LCNECs have a very poor prognosis. Although LCNEC is categorized as a variant of large cell carcinoma, the biological behaviors of LCNEC tumors resemble those of small cell lung carcinomas, and LCNEC reveals the feature of a high-grade neuroendocrine tumor. Because patients with LCNEC have a poor prognosis, surgery alone is not sufficient. Multimodality therapies (including adjuvant chemotherapy) appear to be promising for the improvement of the prognosis in patients with LCNEC, even if the pathologic stage is IA, and should be evaluated further in larger multi-institutional trials.

Pulmonary carcinoid tumors with Cushing's syndrome: an aggressive variant or not?

BACKGROUND

Adrenocorticotropic hormone (ACTH)-secreting pulmonary carcinoid is considered an aggressive variant of carcinoid tumors. Current knowledge is based upon a limited number of reports with few patients.

METHODS

All patients with Cushing's syndrome (CS) resulting from pulmonary carcinoid (PC) who underwent pulmonary resection at our institution from November 1966 through April 1998 were reviewed.

RESULTS

The group studied consisted of 10 males and 13 females. The median age was 39 years (range: 14-71). Pulmonary symptoms were present in 4 patients. Chest radiographs identified an abnormality in 13 patients (57%) and chest computerized tomography (CT) identified an abnormality in all 20 patients examined. Before pulmonary resection, hypophysectomy and bilateral adrenalectomy were performed in 7 patients (30%) each. Median time interval from presentation to pulmonary resection was 17 months (range: 1-228). Lobectomy was performed in 16 patients, segmentectomy was performed in 4 patients, and bilobectomy, pneumonectomy, and wedge excision was performed in 1 patient each. There were no operative deaths. Typical carcinoid was identified in 21 patients (91%) and atypical carcinoid was identified in 2 patients (9%). The median tumor diameter was 1.3 cm (range: 0.3-10). Nineteen patients (83%) underwent mediastinal lymphadenectomy and lymph node metastasis was found in 6 patients (32%) (N1 in 4 patients, N2 in 2 patients). The median follow-up was 78 months (range: 1-432). CS resolved in all of the patients. CS with PC recurred in 4 patients and CS alone recurred in 1 patient. Two patients underwent curative re-resection. Two patients, one with disseminated PC, died at last follow-up.

CONCLUSIONS

Despite long delays in surgical therapy, pulmonary resection for ACTH-secreting PCs results in a favorable prognosis. Anatomic resection with complete mediastinal lymphadenectomy decreases local recurrence. Although rare these tumors do not seem to be as aggressive a variant of typical carcinoid tumors as previously reported.

Large cell neuroendocrine carcinoma of the lung: A retrospective analysis of 144 surgical cases

OBJECTIVE

Large cell neuroendocrine carcinoma of the lung are considered aggressive. However, reported prognoses are heterogeneous and the optimum treatment remains undefined. We retrospectively evaluated outcomes in a series of patients with a pathological diagnosis of large cell neuroendocrine lung carcinoma, who underwent lung resection. We also assessed the utility of chemotherapy in a small subgroup.

PATIENTS AND METHODS

The clinical records of 144 consecutive patients were reviewed in a multicenter study. Survival times, assessed from the day of surgery until death or most recent follow-up, were estimated by the Kaplan-Meier method, and compared by the log rank test.

RESULTS

There were 117 men and 27 women of median age 63 years. Twelve wedge resections, 3 segmentectomies, 95 lobectomies, 7 bilobectomies and 24 pneumonectomies were performed. Induction chemotherapy was given in 21 and postoperative chemotherapy in 24. Pathologically, 73 (50%) were stage I, 29 (20%) stage II, 40 (28%) stage III and 2 stage IV. Postoperative mortality was 2.8% and morbidity 26%. Overall 5-year survival was 42.5%: 52% for stage I, 59% for stage II and 20% for stage III (p=0.001 log-rank test on Kaplan-Meier curves). A trend to better outcome was associated with preoperative or postoperative chemotherapy in stage I disease (p=0.077) compared to no chemotherapy. The response rate to induction chemotherapy was 80% in the 15 patients with data available.

CONCLUSION

large cell neuroendocrine carcinoma of the lung are confirmed as aggressive but are also chemosensitive. Our experience suggests that chemotherapy may improve prognosis in stage I disease.

Large cell carcinoma with neuroendocrine morphology of the lung

We experienced a surgical case of large cell carcinoma with neuroendocrine morphology (LCCNM) of the lung. A 76-year-old man was admitted to our hospital because a routine chest X-ray examination had revealed a nodular shadow in the left lung field. 18F-fluorodeoxyglucose positron emission tomography showed accumulation of fluorodeoxyglucose in an area corresponding to the shadow. Transbronchial lung biopsy failed to give a definitive diagnosis, therefore open lung biopsy was performed because of suspected lung cancer. Needle biopsy was performed, and the tumor was diagnosed as large cell neuroendocrine carcinoma by rapid intraoperative pathological examination. As sampling of hilar lymph nodes revealed no metastasis, left upper segmentectomy was performed for severe obstructive pulmonary disease. Immunohistochemical examination finally diagnosed the tumor as LCCNM. The patient is doing well without recurrence at ten months after surgery.

Bone marrow infiltrate by a poorly differentiated neuroendocrine carcinoma

We report a rare case of bone marrow infiltrate by a neuroendocrine carcinoma. The patient was a 66-year-old man who presented with anemia and thrombocytopenia and with a leukoerythroblastic picture on blood films. A bone marrow biopsy revealed extensive tumor infiltrate with morphological and immunohistochemical features of neuroendocrine origin. There were also multiple nodular lesions in the liver, which showed the same pathology as that in the bone marrow. Since none of the lesions could be identified as the primary tumor, the patient was diagnosed to have a poorly differentiated neuroendocrine carcinoma of unknown primary site.

Pulmonary carcinoid tumors

Carcinoid tumors of the lung are an uncommon group of neoplasms of neuroendocrine origin. Pulmonary carcinoid tumors are typically benign and slow growing. However, more aggressive subtypes may develop early nodal and distant metastases. Although several histologic classification strategies have been proposed to distinguish benign from more aggressive subtypes, the lack of uniformity in terminology has resulted in increased ambiguity and confusion. Because these tumors are generally resistant to chemotherapy, complete surgical resection is the primary form of therapy. Long-term survival for patients with typical carcinoid is excellent but is decreased in those with the atypical subtype. Complete tumor resection with preservation of uninvolved pulmonary parenchyma remains the fundamental goal in the surgical treatment of this unusual clinical entity.

Surgical treatment of other bronchial tumors

Bronchial gland tumors (bronchial carcinoids, adenoid cystic carcinoma, mucoepidermoid carcinoma are the most common), benign tumors and other rare primary malignant neoplasms present as endobronchial tumors. This article discusses the surgical treatment of each of these tumors individually.

The role of radiation therapy and chemotherapy in the management of airway tumors other than small-cell carcinoma and non-small-cell carcinoma

In rare pulmonary tumors, the choice of local and systemic therapy is frequently dictated by the histologic cell type and (generally) by extrapolation from the existing therapeutic literature for that cell type's more common presentation; however, this approach might change. We are in the midst of a new biological and technological era in how approach and treat cancer. In a phase I trial for non-small-cell lung cancer, Hayman et al safely treated with radiation doses as high as 102.9 Gy (to limited volumes) using three-dimensional, conformal radiation [100]. Such techniques facilitate radiation dose escalation for thoracic neoplasms while minimizing normal tissue toxicity, potentially enhancing the therapeutic ratio. Furthermore, the entire human genome has been sequenced recently, and scientists are now in the process of discovering the functions of previously unknown sequences and their protein products. DNA microarrays can be used to analyze small tissue samples for the presence of gene variations or mutations (genotyping), performing the equivalent of several thousand "Southern blot" experiments in only a few days. In the future, patients might receive individually tailored therapy based upon unique molecular-genetic alterations of the tumor.

Immunohistochemical neuroendocrine differentiation is an independent prognostic factor in surgically resected large cell carcinoma of the lung

The clinical significance of neuroendocrine (NE) differentiation is unclear in large cell carcinoma (LCC) of the lung. Fifty-five surgically resected carcinomas of the lung with an original pathologic diagnosis of LCC were reviewed histologically with special attention to NE morphology. Antibodies against neural cell adhesion molecule (NCAM), chromogranin A (CGA) and synaptophysin (SY) were used to confirm the NE differentiation. Thirteen (24%) cases were classified as large cell neuroendocrine carcinoma, 9 (16%) as LCC with NE differentiation, and 33 (60%) as pure LCC. There was no significant difference in overall survival between the three groups. When the 55 carcinomas were divided into three groups depending on the number of NE marker expression, there was significantly better overall survival in the NE > or = 2 (P = 0.02). Multivariate analysis proved NE > or = 2 was an independent predictor of survival. The number of NE markers was more important in terms of survival than histological sub-classification.

Large cell neuroendocrine carcinoma of the lung: a clinicopathologic study of eighty-seven cases

OBJECTIVE

Large cell neuroendocrine carcinoma of the lung is a newly recognized clinicopathologic entity. The clinical characteristics and optimal treatment of patients with large cell carcinomas are not yet established. The aim of this study was to define the clinicopathologic characteristics of large cell neuroendocrine carcinoma.

METHODS

The histologic characteristics of the patients receiving an initial diagnosis of poorly differentiated non-small cell lung carcinoma (n = 484), small cell carcinoma (n = 55), carcinoid (n = 31), and large cell neuroendocrine carcinoma (n = 12) were retrospectively reviewed according to World Health Organization criteria. Immunohistochemistry was performed to confirm the neuroendocrine phenotype. The outcomes and other clinical characteristics of those patients with large cell neuroendocrine carcinoma were retrospectively analyzed and compared with those of patients with poorly differentiated carcinoma of other histologic types.

RESULTS

A total of 87 patients were given a diagnosis of large cell neuroendocrine carcinoma after the histologic review. These patients comprised 3.1% of all patients undergoing resection for primary lung cancer during the same period. The overall 5-year survival was 57%. The 5-year survivals of patients with stage I, II, III, and IV disease were 67%, 75%, 45%, and 0%, respectively. There was no statistically significant difference between the overall survival of patients with large cell neuroendocrine carcinoma and those with other non-small cell lung cancers. There was a significant difference between the survival of patients with stage I large cell neuroendocrine carcinoma and that of patients with the same stage of other non-small cell lung carcinomas. The site of the first documented recurrence was locoregional in 12 patients (34%), distant metastases in 20 patients (57%), and both simultaneously in 3 patients. Locoregional lymph node recurrences were observed frequently. More than 80% of recurrences were found within 1 year after the operation.

CONCLUSION

In terms of prognosis, large cell neuroendocrine carcinoma is distinctly different from other non-small cell lung cancers. The prognosis of large cell neuroendocrine carcinoma was poor, even for early stage disease; the prognosis of the stage I disease of large cell neuroendocrine carcinoma was poorer than that of the same stage of other non-small cell lung cancers. Because of its aggressive clinical behavior and poor prognosis, large cell neuroendocrine carcinoma should be recognized as one of the poorest prognostic subgroups among primary lung cancers, and therefore novel therapeutic approaches should be established.

Pulmonary neuroendocrine carcinomas. A review of 234 cases and a statistical analysis of 50 cases treated at one institution using a simple clinicopathologic classification

CONTEXT

Primary pulmonary neuroendocrine tumors are traditionally classified into 3 major types: typical carcinoid (TC), atypical carcinoid (AC), and large cell neuroendocrine carcinoma (LC) or small cell neuroendocrine carcinoma (SC). Confusion arises frequently regarding the malignant nature of TC and the morphologic differentiation between AC and LC or SC.

OBJECTIVE

To provide clinicopathologic evidence to streamline and clarify the histomorphologic criteria for this group of tumors, emphasizing the prognostic implications.

PATIENTS

To minimize variability in diagnostic criteria and treatment plans, we analyzed a group of patients whose diagnosis and treatment occurred at a single institution. We reviewed 234 cases of primary pulmonary neuroendocrine tumors and thoroughly studied 50 cases of resected tumors from 1986 to 1995.

RESULTS

On the basis of morphologic characteristics and biologic behaviors of the tumors, we agree with many previous investigators that these tumors are all malignant and potentially aggressive. Based on our accumulated data, we have modified Gould criteria and reclassified these tumors into 5 types: (1) well-differentiated neuroendocrine carcinoma (otherwise called TC) (14 cases, with less than 1 mitosis per 10 high-power fields [HPF] with or without minimal necrosis); (2) moderately differentiated neuroendocrine carcinoma (otherwise called low-grade AC) (6 cases, with less than 10 mitoses per 10 HPF and necrosis evident at high magnification); (3) poorly differentiated neuroendocrine carcinoma (otherwise called high-grade AC) (10 cases, with more than 10 mitoses per 10 HPF and necrosis evident at low-power magnification); (4) undifferentiated LC (5 cases, with more than 30 mitoses per 10 HPF and marked necrosis); and (5) undifferentiated SC (15 cases, with more than 30 mitoses per 10 HPF and marked necrosis). The 5-year survival rates were 93%, 83%, 70%, 60%, and 40% for well, moderately, and poorly differentiated, and undifferentiated large cell and small cell neuroendocrine carcinomas, respectively. We found nodal metastasis in 28% of TC in this retrospective review, a figure higher than previously recorded.

CONCLUSION

Using a grading system and terms comparable to those used for many years and used for neuroendocrine tumors elsewhere in the body, we found that classification of pulmonary neuroendocrine carcinomas as well, moderately, poorly differentiated, or undifferentiated provides prognostic information and avoids misleading terms and concepts. This facilitates communication between pathologists and clinicians and thereby improves diagnosis and management of the patient.

Pulmonary large cell carcinomas with neuroendocrine features are high-grade neuroendocrine tumors

BACKGROUND

In 1999, the World Health Organization (WHO) categorized large cell carcinoma with neuroendocrine features as variants of large cell carcinoma and reclassified neuroendocrine lung tumors, especially typical and atypical carcinoid tumors. However, to date, the clinical relationship between these categories of neuroendocrine lung tumors has not been clearly defined.

METHODS

We analyzed 133 cases of neuroendocrine tumors from primary lung carcinoma cases surgically resected. Using electron microscopy and immunohistochemical staining, we classified these cases as typical carcinoid (TC), atypical carcinoid (AC), large cell carcinoma with neuroendocrine features (LCNF), or small cell lung carcinoma (SCLC) based upon the WHO classification.

RESULTS

TC and AC tumors were not related to smoking (p < 0.001) and, unlike LCNF, were found in younger patients (p < 0.001) without a male predominance (p < 0.001). Multivariate analysis revealed that LCNF predicted poorer overall and disease-free survivals comparable with SCLC (overall survival, p = 0.019, hazards ratio, 6.34; disease-free survival, p = 0.007, hazards ratio, 8.19).

CONCLUSIONS

The prognoses of LCNF are comparable with those of SCLC, and LCNF should be classified as high-grade neuroendocrine tumors.

Ectopic pro-opiomelanocortin syndrome

Ectopic POMC syndrome remains one of the most challenging differential diagnoses in endocrinology. Recent progress in the understanding of the tissue specific regulation of POMC gene expression and new insights into the processing of the POMC peptide in nonpituitary tissues has helped elucidate some of the molecular events leading to ectopic expression and secretion of POMC peptides. Corticotropin and other POMC-derived peptides have diverse effects on adrenal steroidogenesis, growth, and extra-adrenal tissues. Differences in POMC gene regulation in the corticotrope versus ectopic POMC-producing tumors provides a scientific framework for the clinical distinction between eutopic and ectopic Cushing's syndrome. In an attempt to revisit recent basic and clinical advances in the diagnosis of ectopic POMC syndrome the authors undertook an extensive literature review of 530 cases in 197 published papers and provided a molecular biologic, demographic and diagnostic update. According to this review, the four most common causes of ectopic POMC syndrome are the small cell carcinoma of the lung (27%), bronchial carcinoids (21%), islet cell tumor of the pancreas (16%), and thymic carcinoids (10%). Although the clinical features of patients with ectopic POMC syndrome are similar to those with Cushing's disease, subgroup analysis reveals a broad spectrum of severity and progression of signs and symptoms of hypercortisolism. The endocrine workup of a patient with suspected ectopic POMC syndrome includes the establishment of pathologic hypercortisolism, diagnosis of corticotropin dependency, and the differential diagnosis of corticotropin-dependent Cushing's syndrome. The use of a variety of baseline endocrine values, dynamic endocrine testing, and invasive procedures leads to the correct diagnosis in the majority of patients with ectopic POMC syndrome. Diagnostic imaging, including conventional radiological techniques and somatostatin receptor scintigraphy, aids in the correct localization and eventual treatment of ectopic POMC production.

Bronchial carcinoid tumors of the thorax: spectrum of radiologic findings

Bronchial carcinoid tumors are neuroendocrine neoplasms that range from low-grade typical carcinoids to more aggressive atypical carcinoids and therefore demonstrate a wide spectrum of clinical behaviors and histologic features. Typical and atypical bronchial carcinoids have similar imaging features. Because most bronchial carcinoids are located in central airways, radiologic findings are usually related to bronchial obstruction. Central bronchial carcinoids manifest as an endobronchial nodule or hilar or perihilar mass with a close anatomic relationship to the bronchus. The mass is usually a well-defined, round or ovoid lesion and may be slightly lobulated at radiography and computed tomography (CT). Associated atelectasis, air trapping, obstructing pneumonitis, and mucoid impaction may also be seen. Peripheral bronchial carcinoids appear as solitary nodules. Calcification is common and is easily visualized at CT. Bronchial carcinoids demonstrate high signal intensity on T2-weighted and short-inversion-time inversion recovery magnetic resonance images. Prognosis of bronchial carcinoids is highly dependent on histologic findings: Atypical carcinoids have certain features that suggest a more aggressive nature. Typical bronchial carcinoids generally have an excellent prognosis, whereas atypical bronchial carcinoids have a worse prognosis. Therefore, understanding the histologic, clinical, and radiologic features of bronchial carcinoids facilitates accurate diagnosis and helps optimize surgical planning.

Morphometry confirms the presence of considerable nuclear size overlap between "small cells" and "large cells" in high-grade pulmonary neuroendocrine neoplasms

We morphometrically evaluated 5-micron H&E-stained sections from 28 surgically resected high-grade pulmonary neuroendocrine neoplasms, including 16 small cell lung carcinomas (SCLCs) and 12 large cell neuroendocrine carcinomas (LCNECs). For each case, 200 tumor nuclei and 20 to 100 normal lymphocytes were measured. The frequency distributions of tumor cell/lymphocyte (TC/L) size ratios were plotted in bins ranging from 1 to 6, classified into 6 histogram types with TC/L size ratio peaks ranging from 2 to 6 (A-E) and a histogram with a wide distribution (F). SCLCs fit histograms A through E; LCNECs, A through F. Morphometry demonstrated considerable nuclear size overlap in high-grade neoplasms. Approximately one third of SCLCs exhibited considerable numbers of neoplastic cells that were larger than 3 normal lymphocytes, while 4 of 12 LCNECs had a predominant number of small cells. Ten tumors exhibited a B histogram with a "borderline" peak TC/L of 3. The rule that a TC/L size ratio larger than 3 helps distinguish "large" from "small" neoplastic cells was confirmed in only 9 of 28 cases. The use of more generic terminology such as "high-grade neuroendocrine carcinoma" or "grade III neuroendocrine carcinoma" for SCLC and LCNEC is discussed.

Microtubule-associated protein-2: a new sensitive and specific marker for pulmonary carcinoid tumor and small cell carcinoma

Microtubule-associated proteins (MAPs) are a major component of cytoskeleton family proteins associated with microtubule assembly. MAP-2 has been shown to be specifically expressed in neuronally differentiated cells. Pulmonary neuroendocrine carcinomas such as carcinoid tumors and small cell carcinomas are derived from neuroendocrine cells. We hypothesize that neuroendocrine cells may also express MAP-2, and therefore, MAP-2 may be used as a marker for pulmonary carcinomas of neuroendocrine differentiation. To investigate the utility of using MAP-2 expression to separate pulmonary neuroendocrine from non-neuroendocrine tumors, we examined the expression of MAP-2 immunohistochemically in 100 cases of pulmonary carcinomas. The immunoperoxidase method with antigen retrieval was used to characterize the expression of MAP-2, chromogranin, synaptophysin, and neuron-specific enolase in 25 small cell carcinomas, 25 carcinoid tumors, 25 adenocarcinomas, and 25 squamous cell carcinomas. All tumors were lung primaries. All 25 cases of carcinoid tumors (100%) as well as 23 of 25 cases (92%) of small cell carcinomas were positive for MAP-2. Four of 25 cases (16%) of adenocarcinomas were positive for MAP-2 and synaptophysin. Among the 25 squamous carcinomas, 4 cases (16%) were positive for MAP-2, 2 cases (8%) were positive for synaptophysin, 11 cases (44%) were positive for neuron-specific enolase, and none was positive for chromogranin. In conclusion, MAP-2 is a new sensitive and specific marker for the pulmonary tumors of neuroendocrine differentiation. We recommend that MAP-2 be added to immunohistochemical panels to separate non-neuroendocrine from neuroendocrine lung tumors.

Adjuvant chemotherapy for large cell carcinoma with neuroendocrine features

BACKGROUND

In 1999, the World Health Organization categorized large cell neuroendocrine carcinoma, large cell carcinoma with neuroendocrine differentiation, and large cell carcinoma with neuroendocrine morphology as a variant of large cell carcinoma. Patients with large cell carcinoma with neuroendocrine features have poor prognoses, comparable to those for small cell lung carcinoma. Small cell lung carcinoma is sensitive to chemotherapy; however, it is still unclear whether large cell carcinoma with neuroendocrine features is responsive to adjuvant chemotherapy.

METHODS

The authors analyzed 73 patients with large cell carcinoma with neuroendocrine features who underwent resection of the tumor and studied the effect of adjuvant chemotherapy for large cell carcinoma with neuroendocrine features.

RESULTS

In patients with Stage I disease, the overall survival for patients with adjuvant chemotherapy based on cisplatin, carboplatin, or cyclophosphamide, which were used as standard chemotherapy for small cell lung carcinoma, were significantly higher than the overall survival for patients without adjuvant chemotherapy. In patients with Stage II, III, and IV disease, there was no significant difference between patients with adjuvant chemotherapy and without adjuvant chemotherapy.

CONCLUSIONS

Adjuvant chemotherapy based on cisplatin, carboplatin, or cyclophosphamide prolongs survival of patients with large cell carcinoma with neuroendocrine features in early stage.

Large cell neuroendocrine carcinoma of the lung: clinical, CT, and pathologic findings in 11 patients

The purpose of this study was to describe the clinical, computed tomographic (CT), and pathologic findings of large cell neuroendocrine carcinoma (LCNEC) of the lung. CT and pathologic findings as well as clinical features of surgically proven LCNEC of the lung were reviewed retrospectively in 11 consecutive patients (eight men and three women; mean age, 63 years; range, 44-77 years). Chest CT showed peripheral mass or nodule (n = 8) and central mass with distal atelectasis (n = 3). Six tumors were accompanied by mediastinal (n = 3) and hilar (n = 3) lymph node enlargement at CT. On pathologic examination, all resected tumors showed necrosis of variable extent (mean: 38%, range; 10-70%). The areas of intrinsic lipoid pneumonia and tumor emboli in two patients appeared at CT as areas of ground-glass opacity surrounding the tumor. Mediastinal nodal metastases were seen in three (27%) patients. Pathologic staging of 11 patients was IB in six, IIA in one, IIB in one, IIIA in two, and IIIB in one. Follow-up data showed extrathoracic metastases in four patients at mean follow-up period of 15 months. One patient died of distant metastasis 5 months after the surgery. CT findings of LCNEC of the lung are nonspecific and similar to those of other non-small cell lung cancers and extrathoracic metastasis is seen in approximately one third of the patients with follow-up study.

The carcinoid syndrome: an unusual cause of valvular heart disease

A 30-year-old woman presented to the Emergency Department with complaints of shortness of breath, orthopnea, and a severe reduction in exercise tolerance. The symptoms were the result of severe valvular heart disease that resulted from a bronchopulmonary carcinoid tumor. The carcinoid syndrome is a distinctive clinical syndrome seen in patients with carcinoid tumors. Cardiac valvular lesions are seen in the majority of patients with the carcinoid syndrome and represent the most clinically significant consequence of the carcinoid syndrome. This case report discusses carcinoid tumors, the carcinoid syndrome induced by these tumors, and the therapeutic options in the management of carcinoid tumors.

Clinical characterization of pulmonary large cell neuroendocrine carcinoma and large cell carcinoma with neuroendocrine morphology

BACKGROUND

Large cell carcinoma has been classified as four potential types based on its neuroendocrine morphology and evidence of neuroendocrine differentiation discernible by immunohistochemistry or electron microscopy. However, the clinical relation among these four categories has not been clearly defined. In 1999, the World Health Organization (WHO) categorized large cell neuroendocrine carcinoma as a variant of large cell carcinoma. MATERIAL AND METHODS The authors analyzed 119 cases of large cell carcinoma from a total of 2070 primary lung carcinoma cases resected surgically between 1969-1999. Using light microscopy, electron microscopy, and immunohistochemical staining, the authors reclassified these cases into large cell neuroendocrine carcinoma (LCNEC), large cell carcinoma with neuroendocrine differentiation (LCCND), large cell carcinoma with neuroendocrine morphology (LCCNM), and classic large cell carcinoma (CLCC).

RESULTS

In multivariate analyses, the authors found that large cell carcinoma with neuroendocrine features, which combined LCNEC, LCCND, and LCCNM, impacted both the overall survival and disease-free survival of patients. The clinical behavior of LCCNM was similar to that of LCNEC.

CONCLUSIONS

Large cell carcinomas with neuroendocrine features appear to be more clinically aggressive than CLCCs. The authors' findings suggest that the histologic identification of neuroendocrine features in tumor tissue from patients diagnosed with large cell carcinoma of the lung may have clinical relevance.

Expression of the E-cadherin-catenin complex in lung neuroendocrine tumours

Neuroendocrine tumours (NETs) of the lung represent a wide spectrum of phenotypically distinct entities, with differences in tumour progression and aggressiveness. The redistribution and/or the loss of various cell adhesion molecules, such as the E-cadherin-catenin complex, play a predominant role in carcinogenesis and in tumour invasion. Moreover, mutations in exon 3 of the beta-catenin gene, the adenomatous polyposis coli (APC) gene or the E-cadherin genes were previously found to result in intracytoplasmic and/or nuclear beta-catenin protein accumulation, activating nuclear transcription of target genes involved in tumour progression. In the present study, the distribution of the components of this E-cadherin-catenin complex has been investigated by immunohistochemistry and an attempt has been made to correlate the abnormal expression pattern with the eventual detection of mutations in the corresponding genes. This study included 27 primary NETs of the lung, with nine typical carcinoids (TCs), three atypical carcinoids (ACs), and 15 large cell neuroendocrine carcinomas (LCNECs). The E-cadherin-catenin complex remained expressed in most of these lung tumours, but with a cytoplasmic and/or nuclear redistribution of beta-catenin, E-cadherin, and alpha-catenin; abnormal positive immunoreactivity was observed in 24 (88.9%), in 21 (80.8%), and in 20 (76.9%) NETs, respectively. In the great majority of cases, there was a good correlation between the expression of these three proteins, but no significant association with histological classification or TNM stage. Thus, E-cadherin-complex redistribution cannot be considered a prognostic marker in NET of the lung. Of particular interest was the frequent focal beta-catenin nuclear immunostaining (55.5% in total), which was also unrelated to histological type or TNM stage. However, this study failed to detect any mutation in exon 3 of the beta-catenin gene, in the APC gene or in the E-cadherin gene. These data suggest another mechanism of regulation of beta-catenin in these tumours.

The surgical spectrum of pulmonary neuroendocrine neoplasms

OBJECTIVES

The purpose of this study is to review our experience with the spectrum of neuroendocrine neoplasms of the lung with emphasis on the histopathologic classification and surgical therapy of each class of neoplasm.

DESIGN

This retrospective review covers the entire spectrum of neuroendocrine neoplasms of the lung over an 11-year period (January 1985 to December 1995) in a university hospital setting. Only patients who underwent surgical resection were included in this review.

PATIENTS

During this period, a total of 77 patients underwent lung resection for the following neuroendocrine neoplasms: typical carcinoid (TC), 50 patients; atypical carcinoid (AC), 5 patients; large cell neuroendocrine carcinoma (LCNEC), 9 patients; mixed large-small cell neuroendocrine carcinoma (LSNEC), 4 patients; or small cell neuroendocrine carcinoma (SCC), 9 patients. There were 37 men (48.1%) and 40 women (51.9%) among the patients, with a mean age of 57.9 years (range, 14 to 87 years).

INTERVENTIONS

Primary surgical resection consisted of the following procedures: 52 lobectomies (67.5%); 10 pneumonectomies (13%); 13 limited resections (16.9%); 1 left main bronchus sleeve resection; and 1 carinal resection. Six patients had the following concomitant procedures: pericardiectomy, 2 patients; mediastinoscopy, 1 patient; chest wall resection, 1 patient; stapling blebs, 1 patient; and transdiaphragmatic liver biopsy, 1 patient. Four patients underwent bilobectomies, and two patients underwent multiple wedge resections.

RESULTS

The hospital mortality rate was 2.6% (2 of 77 patients), and both patients died of pulmonary failure. Follow-up was obtained in 62 of 77 patients (80.9%) for an average of 38.1 months (range, 2 to 132 months). There were a total of 13 deaths, and 8 were disease-related (LCNEC, 4 deaths; SCC, 2 deaths; LSNEC, 1 death; and AC tumor, 1 death. The mean disease-free intervals for patients with these neoplasms were the following: TC tumor, 41.3 months; AC tumor, 20 months; LCNEC, 20.4 months; LSNEC, 25 months; and SCC, 48 months. The overall 3-year survival rate was 45.2% (28 of 62 patients).

CONCLUSION

This report will emphasize the classification, surgical management, and treatment considerations of pulmonary neuroendocrine neoplasms. Despite the poor overall prognosis in high-grade neuroendocrine tumors of the lung, surgery remains a viable adjunct in the early stages of this disease.

Prognostic factors in neuroendocrine lung tumors: a Spanish Multicenter Study. Spanish Multicenter Study of Neuroendocrine Tumors of the Lung of the Spanish Society of Pneumonology and Thoracic Surgery (EMETNE-SEPAR)

BACKGROUND

This study examines the experience of the Spanish Multicenter Study of Neuroendocrine Tumors of the Lung through the clinical data and behavior of patients treated for this pathologic process.

METHODS

From 1980 to 1997, 361 cases of neuroendocrine carcinomas (NEC) were treated surgically. Patients were enrolled in a protocol using the pathologic and follow-up reports. According to Dreslers' criteria, the cases were segregated into grade 1 (typical carcinoid), grade 2 (atypical carcinoid), grade 3 large cell type, and grade 3 small cell type. Several variables were reviewed in all patients. Statistical analysis was performed to determine whether clinical characteristics and differentiation were associated with significant differences in the prognosis.

RESULTS

A total of 261 cases of NEC were identified with grade 1, 43 with grade 2, and with grade 3: 22 of large and 35 of small cells. Five-year survival for different grades was as follows: grade 1, 96%; 2, 72%; 3 large cell type, 21%; and 3 small cell type, 14%. When a comparative analysis between typical and atypical carcinoids was performed a significant difference for mean age, tumor size, nodal metastases, and recurrence was observed. However, female sex, nodal metastases, and recurrence rate differed between atypical carcinoids and grade 3 NEC of large cells. A difference in recurrence rate was found between patients with both types of grade 3 NEC.

CONCLUSIONS

The progressive deterioration of tumor organization highlights that neuroendocrine tumors constitute a continuous spectrum. A careful observation of pathologic findings is necessary to individualize their prognostic factors.