Large cell neuroendocrine carcinoma of the lung: radiologic and pathologic findings

Survival outcomes of surgery in patients with pulmonary large-cell neuroendocrine carcinoma: a retrospective single-institution analysis and literature review

Background

Pulmonary large-cell neuroendocrine carcinoma (pLCNEC) is a very rare malignancy originating from the lung and bronchus, and its biological behaviour, clinical diagnosis, treatment and prognosis are poorly understood. Thus, the clinical characteristics and surgical treatment-related prognostic factors of this rare disorder must be explored.

Results

The clinical data of 59 patients (48 males and 11 females) who were treated by surgery and diagnosed with pLCNEC by postoperative pathology at Peking Union Medical College Hospital from April 2004 to April 2019 were analysed retrospectively. The median patient age was 62 years (38–79 years), and the median duration of disease was 2 months (0.5–18 months). Compared with other lung malignancies, pLCNEC lacks specific clinical symptoms and imaging features, and preoperative biopsy pathology is often insufficient to confirm the diagnosis. The corresponding numbers of patients who were classified into stages I, II, III and IV according to the postoperative pathological tumour-nodal-metastasis stage were 25, 12, 15 and 7, respectively. The median overall survival was 36 months (0.9–61.1 months). The 1-year, 3-year and 5-year survival rates were 76.3%, 49% and 44.7%, respectively. The tumour stage exerted a significant effect on survival (Cox multivariate analysis p < 0.05).

Conclusions

For patients with resectable pLCNEC, multidisciplinary therapy based on surgery may have good survival benefits, and tumour stage is an independent risk factor for the prognosis of pLCNEC.

Exploring imaging features of molecular subtypes of large cell neuroendocrine carcinoma (LCNEC)

OBJECTIVES

Radiological characteristics and radiomics signatures can aid in differentiation between small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC). We investigated whether molecular subtypes of large cell neuroendocrine carcinoma (LCNEC), i.e. SCLC-like (with pRb loss) vs. NSCLC-like (with pRb expression), can be distinguished by imaging based on (1) imaging interpretation, (2) semantic features, and/or (3) a radiomics signature, designed to differentiate between SCLC and NSCLC.

MATERIALS AND METHODS

Pulmonary oncologists and chest radiologists assessed chest CT-scans of 44 LCNEC patients for 'small cell-like' or 'non-small cell-like' appearance. The radiologists also scored semantic features of 50 LCNEC scans. Finally, a radiomics signature was trained on a dataset containing 48 SCLC and 76 NSCLC scans and validated on an external set of 58 SCLC and 40 NSCLC scans. This signature was applied on scans of 28 SCLC-like and 8 NSCLC-like LCNEC patients.

RESULTS

Pulmonary oncologists and radiologists were unable to differentiate between molecular subtypes of LCNEC and no significant differences in semantic features were found. The area under the receiver operating characteristics curve of the radiomics signature in the validation set (SCLC vs. NSCLC) was 0.84 (95% confidence interval (CI) 0.77-0.92) and 0.58 (95% CI 0.29-0.86) in the LCNEC dataset (SCLC-like vs. NSCLC-like).

CONCLUSION

LCNEC appears to have radiological characteristics of both SCLC and NSCLC, irrespective of pRb loss, compatible with the SCLC-like subtype. Imaging interpretation, semantic features and our radiomics signature designed to differentiate between SCLC and NSCLC were unable to separate molecular LCNEC subtypes, which underscores that LCNEC is a unique disease.

Management of pulmonary neuroendocrine tumors

Neuroendocrine tumors (NETs) of the lung are divided into 4 major types: small cell lung cancer (SCLC), large cell neuroendocrine carcinoma (LCNEC), atypical carcinoid (AC) or typical carcinoid (TC). Each classification has distinctly different treatment paradigms, making an accurate initial diagnosis essential. The inconsistent clinical presentation of this disease, however, makes this difficult. The objective of this manuscript is to detail the diagnosis and management of the well differentiated pulmonary carcinoid (PC) tumors. A multidisciplinary approach to work up and treatment should be utilized for each patient. A multimodal radiological work-up is used for diagnosis, with contrast enhanced CT predominantly utilized and functional imaging techniques. A definitive diagnosis is based on tissue findings. Surgical management remains the mainstay of therapy and can be curative. In those with advanced disease, medical treatments consist of somatostatin analog (SSA) therapy, targeted therapy, chemotherapy or peptide receptor radionuclide therapy. SSAs are the standard of care in those with metastatic NETs, using either Octreotide long acting repeatable (LAR) or lanreotide as reasonable options, despite a scarcity of prospective data in PCs. Targeted therapies consist of everolimus which is approved for use in PCs, with various studies showing mixed results with other targeted agents. Additionally, radionuclide therapy may be used and has been shown to increase survival and to reduce symptoms in some studies. Prospective trials are needed to determine other strategies that may be beneficial in PCs as well as sequencing of therapy. Successful diagnosis and optimal treatment relies on a multidisciplinary approach in patients with lung NETs. Clinical trials should be used in appropriate patients.

Pulmonary malignant melanoma with distant metastasis assessed by positron emission tomography-computed tomography

Melanoma is a cutaneous malignant neoplasm of melanocytes. Primary malignant melanoma (MM) of the lung is very rare. Although previous reports have described the radiologic features of pulmonary MM, its rarity means that many factors are unknown. Thus, radiologic diagnosis is very difficult. Furthermore, there is little information regarding diagnostic application and/or the usefulness of [¹⁸F]‐fluorine‐2‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography‐computed tomography (FDG‐PET‐CT) for primary pulmonary MM. A 69‐year‐old patient with a productive cough lasting three weeks was admitted to our hospital. Chest CT showed a large single mass with a multi‐lobulated margin and homogeneous enhancement in the right upper lobe, which was subsequently diagnosed as a primary pulmonary MM with multiple metastases. On PET‐CT images, the pulmonary mass and multiple bone lesions showed very increased uptakes of FDG. Considering that pulmonary metastasis from a mucocutaneous melanoma is the main differential diagnosis of primary pulmonary MM, systemic assessment of the whole body is more important than for other types of lung malignancies. This report introduces PET‐CT as a useful diagnostic modality for pulmonary MM, especially in cases of distant multiple metastases.

[Clinical Analysis of 22 Cases of Pulmonary Large Cell Neuroendocrine Cancer]

背景与目的

肺大细胞神经内分泌癌是肺原发恶性肿瘤的一种少见类型，由于其特殊的生物学行为、复杂的病理学标志、多样的影像学表现及欠佳的治疗疗效，亟待进行临床探讨。本研究旨在分析肺大细胞神经内分泌癌的临床资料，为进一步提高其诊治水平提供依据。

方法

回顾性分析22例肺大细胞神经内分泌癌患者的临床特征、诊治情况及预后。

结果

肺大细胞神经内分泌癌好发于有大量吸烟史的老年男性，临床表现以咳嗽、咳痰、咯血、胸痛为主。计算机断层扫描（computed tomography, CT）表现以周围型肿块为主，可伴不均匀强化和坏死。免疫组化神经内分泌分化标志物Syn、CgA和CD56的阳性表达率分别为72.7%、68.2%和68.2%。17例行手术治疗，术后10例接受辅助治疗，5例行姑息化疗。单因素分析提示吸烟指数（P=0.029）、淋巴结转移（P=0.034）、肿瘤-淋巴结-转移（tumor-node-metastasis, TNM）分期（P=0.005）、治疗方法（P=0.047）、术后辅助化疗（P=0.014）是预后的影响因素，多因素分析提示淋巴结转移（P=0.045）及术后辅助化疗（P=0.024）是预后的影响因素。

结论

肺大细胞神经内分泌癌缺乏特异性的临床表现，确诊依赖术后病理，各种治疗疗效欠佳。淋巴结转移状态及术后辅助化疗是影响预后的重要因素。

Spectrum of pulmonary neuroendocrine proliferations and neoplasms

Neuroendocrine neoplasms are ubiquitous tumors found throughout the body, most commonly in the gastrointestinal tract followed by the thorax. Neuroendocrine cells occur normally in the bronchial and bronchiolar epithelium and may be solitary or may occur in clusters. Although neuroendocrine cell proliferations may be found in association with chronic lung disease, a broad range of neuroendocrine proliferations and neoplasms may occur and exhibit variable biologic behavior. Diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH) is a diffuse idiopathic form of neuroendocrine cell hyperplasia and is considered a preinvasive lesion that may give rise to carcinoid tumors. Patients with DIPNECH are typically older women who may be asymptomatic or may present with chronic respiratory symptoms. DIPNECH manifests as multifocal bilateral pulmonary micronodules on expiratory high-resolution computed tomographic (CT) images; the air trapping is secondary to constrictive bronchiolitis. Carcinoid tumors are low-grade malignant neoplasms that typically affect symptomatic children and young adults. Carcinoids manifest as well-defined pulmonary nodules or masses that are often closely related to central bronchi. They may exhibit intrinsic calcification and contrast material enhancement at CT, and patients with carcinoids may have postobstructive atelectasis and pneumonia. Although typical carcinoids are indolent neoplasms and patients have a good prognosis, atypical carcinoids are aggressive malignancies with a propensity for metastasis. Both are optimally treated with complete surgical excision. Large cell neuroendocrine carcinoma and small cell lung cancer are highly aggressive neuroendocrine malignancies that usually affect elderly smokers. These tumors manifest with large peripheral or central pulmonary masses. Local invasion, intrathoracic lymphadenopathy, and distant metastases are frequent at presentation. As a result, affected patients may not be candidates for surgical resection, are often treated with chemotherapy with or without radiation, and have a poor prognosis.

A long-term survivor with pulmonary large-cell neuroendocrine carcinoma

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) has been characterized by highly aggressive behavior, with early spread to both regional lymph nodes and distant sites and a rapidly fatal course. In fact, no reports have described an advanced pulmonary LCNEC patient who has had long-term survival. A patient with large-sized pulmonary LCNEC, who is free of disease 11 years after surgery and postoperative chemotherapy, was reported.

Large cell neuroendocrine carcinoma of the lung with a cystic appearance on computed tomography

Almost all reported cases of large cell neuroendocrine carcinoma (LCNEC) of the lung are solid-type tumors. We encountered a rare case of LCNEC displaying a cystic shape. An abnormal cystic shadow was revealed on chest computed tomography in a 71-year-old man who underwent total gastrectomy due to gastric cancer 5 years earlier. The cystic lesion enlarged from 7 mm to 16 mm over 7 months, so surgery was performed for definitive diagnosis and therapy. Microscopy revealed rosette patterns, a high mitotic rate and a large area of necrosis. Neuroendocrine differentiation was confirmed on immunohistochemical examinations using chromogranin, synaptophysin and NCAM (CD56). Given these findings, LCNEC was diagnosed. This is the first report of LCNEC with a cystic shape. This case challenges preconceptions regarding the radiographic appearance of LCNEC.

Pleomorphic carcinoma of lung: comparison of CT features and pathologic findings

PURPOSE

To retrospectively evaluate computed tomographic (CT) features of pleomorphic carcinoma of the lung and to compare these features with pathologic findings.

MATERIALS AND METHODS

Ten patients (10 men, three women; mean age at diagnosis, 64.1 years; range, 43-75 years) with pleomorphic carcinoma treated from June 2000 to January 2003 were selected from two institutions. Two radiologists retrospectively reviewed CT features, which included size and location of tumor, presence of calcification, attenuation values and internal architecture of the mass, and invasion of pleura and chest wall. Attenuation values of the mass on CT scans were compared with pathologic findings in tumors in available gross specimens. Follow-up CT scans were not routinely obtained except in two patients with progressive pleural effusion and rapid growth of the tumor as seen on serial chest radiographs.

RESULTS

On unenhanced CT scans, attenuation of the tumor was similar to that of the surrounding muscle. Calcification within the tumor was visible in one patient. Invasion of chest wall was noted in two patients. Seven patients had pleural invasion. Tumors were located at the lung periphery in nine patients. On contrast material-enhanced CT scans, lesions with the longest diameter larger than 5 cm showed central low-attenuation areas with substantial enhancement in the tumor periphery; in comparison, lesions with the longest diameter smaller than 5 cm showed homogeneous enhancement. Size of two lesions with the longest diameter larger than 5 cm increased rapidly after a follow-up of shorter than 3 weeks. Low-attenuation areas on contrast-enhanced CT scans were found to correspond to areas of myxoid degeneration, necrosis, or hemorrhage in pathologic specimens.

CONCLUSION

Findings of this study suggest that pleomorphic carcinomas of the lung preferentially manifest as large peripheral lung neoplasms with a central low-attenuation area and frequently invade the pleura and chest wall.

CT Findings of Surgically Resected Large Cell Neuroendocrine Carcinoma of the Lung in 38 Patients

OBJECTIVE

We sought to assess the CT features of surgically resected large cell neuroendocrine carcinoma of the lung.

MATERIALS AND METHODS

The cases of all patients who underwent surgical resection for primary lung cancer in a single institution from 1993 to 2000 and who received an initial diagnosis of poorly differentiated non-small cell lung carcinoma, small cell carcinoma, carcinoid tumor, and large cell neuroendocrine carcinoma were histologically reviewed. The findings for 43 patients were histologically reclassified and confirmed as large cell neuroendocrine carcinoma. The CT scans available for 38 patients were evaluated by two observers.

RESULTS

In the 38 patients, six central tumors and 32 peripheral tumors, with diameters ranging from 12 to 92 mm (mean +/- SD, 32 +/- 19 mm), were identified. None of the tumors had air bronchograms or calcification in the mass or nodule. Of the 19 patients with thin-section CT scans, 14 (74%) showed the tumor-lung interface as well defined and five (26%) showed the interface to be ill defined. Lobulation was identified on 15 scans (79%) and spiculation was evident on six scans (32%). On contrast-enhanced CT scans, inhomogeneously enhanced tumors appeared to be larger (51 +/- 18 mm) than homogeneously enhanced tumors (25 +/- 10 mm; p < 0.001). At histopathologic examination, gross necrosis was noted in 20 of 28 patients who had undergone contrast-enhanced CT, and the cause of inhomogeneous enhancement on CT scans was determined to be intratumoral necrosis. Multiple microscopic necroses were present in all 28 patients.

CONCLUSION

Large cell neuroendocrine carcinoma usually appears as a well-defined and lobulated tumor with no air bronchograms or calcification. The inhomogeneous enhancement (caused by necrosis) seen in large cell neuroendocrine carcinomas with large diameters is not necessarily apparent in small-diameter (< 33 mm) large cell neuroendocrine carcinomas, even if the tumor contains necrosis.

Pulmonary large-cell neuroendocrine carcinoma (LCNEC)

OBJECTIVE

The experiences on the treatment of seven consecutive patients with large-cell neuroendocrine carcinoma (LCNEC) were studied, observed over 6 years from 1992. Since LCNEC was recognized as a separate histological entity, only very few series have been reported. Together with the carcinoids (atypical and typical) and the small-cell lung carcinoma (SCLC), it forms the spectrum of neuroendocrine tumors.

METHODS

Between 1992 and 1997, seven patients who underwent surgical resection were diagnosed as LCNEC postoperatively. Mean age was 65 years (range 54-77 years), five patients were male, all patients were heavy smokers. One patient was staged as IA, four as IB, one as IIIB and one as IV.

RESULTS

In five patients, preoperative diagnosis was unknown, in one squamous cell carcinoma and in one adenocarcinoma was suspected. There were four lobectomies, two bilobectomies and one resection of the lingular division with a wedge resection of the upper division of the left upper lobe. Three patients received adjuvant chemotherapy and one, adjuvant radiotherapy. Survival ranged from 7 to 39 months. There are no patients currently alive.

CONCLUSIONS

LCNEC is a high-grade neuroendocrine tumor with a poor prognosis. In our patients, after surgical resection or multimodality treatment, all have developed widespread metastatic disease with a rapidly fatal course. Due to the rarity of this tumor, the incidence, prognosis and optimal treatment remain to be determined.

Neuroendocrine tumors of the bronchopulmonary tract: a reappraisal of their classification after 20 years

This article is an overview of the classification of pulmonary neuroendocrine neoplasms, their presentation, their pathologic appearance, and their clinical management. In addition, the original classification, based on histologic features, is reassessed in the light of newer areas in study, including neurosecretory products, neuroendocrine markers, ultrastructural studies, ploidy analysis, cell adhesion markers, apoptosis, oncogene mutation analysis, and genetic alterations. The histologic classification proposed in 1983 remains the single most valuable factor in establishing the diagnosis and, together with the TNM status, the prognosis of this group of interesting neoplasms.

Unusual primary lung tumors: a radiologic-pathologic overview

Although the great majority of lung carcinomas are histologically characterized as adenocarcinoma, squamous cell carcinoma, large cell undifferentiated carcinoma, or small cell carcinoma, a variety of rare benign and malignant lung tumors may sporadically affect the lung. Several nonneoplastic tumorlike lesions are seen infrequently but are also part of the differential diagnosis for lung masses. Conventional radiographic findings, although of limited value in the diagnosis of these entities, should be examined carefully when lung tumors are suspected. Computed tomography (CT) is well suited for making a definitive diagnosis of some disease processes. CT helps determine the location and features of the lesions and depicts associated findings to help document the extent of disease. The differential diagnosis can be narrowed when there are typical CT features (eg, the presence of fat in lipoid pneumonia). Although unusual primary lung tumors are difficult to diagnose on the basis of imaging findings alone because such findings are nonspecific in the majority of cases, cross-sectional imaging can play an important role in the diagnostic work-up of these unusual tumors by delineating their extent and directing the radiologist or bronchoscopist to the appropriate biopsy site.