Relevance of Lymph Node Micrometastases in Radically Resected Endobronchial Carcinoid Tumors

Atypical carcinoid tumor of the lung: A rare entity

Carcinoids account for approximately 2% of all lung tumors, and the atypical carcinoids (ACs) are much rarer than typical carcinoid. Here, we report a rare case of AC tumor of the lung. A 50-year-old female patient presented with left-sided chest pain for 1 year, cough for 6 months, and loss of appetite for 6 months. Contrast-enhanced computed tomography scan of the thorax revealed an ill-defined heterogeneously enhancing soft-tissue attenuation lesion in the mediastinum following which transthoracic biopsy was done. Histomorphology and immunohistochemistry were consistent with AC, a neuroendocrine tumor. Combination chemotherapy consisting of cisplatin and etoposide was administered as initial chemotherapy.

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.

Surgical Resection for Pulmonary Carcinoid: Long-Term Results of Multicentric Study-The Importance of Pathological N Status, More Than We Thought

BACKGROUND

Histological subdivision into typical (TC) and atypical (AC) is crucial for treatment and prognosis of lung carcinoids but can be also very challenging, even for experts. In this study, we aimed to strengthen or reduce the prognostic value of several pathological, clinical, or per-operative factors some of which are still controversial.

METHODS

We retrospectively reviewed clinical records related to 195 patients affected by TC (159) or AC (36) surgically treated between 2000 and 2014, in three different centers. Survival and subtypes comparison analyses were performed to identify potential prognostic factors.

RESULTS

TCs showed a lower rate of nodal involvement than ACs (N0 = 94.9%; N1 = 1.9%; N2 = 3.2% in typical and N0 = 63.8%; N1 = 16.6%; N2 = 19.4% in atypical carcinoids, respectively, p < 0.0001). Long-term oncological results of resected carcinoids were significantly better in TCs than ACs with higher 5- and 10-year overall survival rates (97.2 and 88.2% vs. 77.9 and 68.2%, respectively; p = 0.001) and disease-free survival rates (98.2 and 90.3% in typical and 80.8 and 70.7% atypical carcinoids, respectively; p = 0.001). Risk factors analysis revealed that AC subtype [HR 4.33 (95% CI 1.72-8.03), p = 0.002], pathological nodal involvement [HR 3.05 (95% CI 1.77-5.26), p < 0.0001], and higher SUV_max [HR 4.33 (95% CI 1.03-7.18), p = 0.002] were independently and pejoratively associated with overall survival. Factors associated with a higher risk of recurrence were AC subtype [HR 6.13 (95% CI 1.13-18.86), p = 0.002]; nodal involvement [HR 5.48 (95% CI 2.85-10.51), p < 0.0001]; higher Ki67 expression level [HR 1.09 (95% CI 1.01-1.20), p = 0.047]; and SUV_max [HR 1.83 (95% CI 1.04-3.23), p = 0.035].

CONCLUSION

Surgery for lung carcinoids allows satisfactory oncological results which mainly depend on carcinoid subtype dichotomy, pathological nodal status, and SUV_max.

Bronchial and Thymic Carcinoid Tumors

Bronchial and thymic carcinoids are rare. We present epidemiologic data and potential risk factors. The approach to bronchial and thymic carcinoid patients is discussed, from the initial diagnosis and evaluations to treatment. These malignancies follow staging systems of their site of origin. Because bronchial and thymic carcinoids are rare, we use many treatment strategies that have been demonstrated in gastrointestinal and pancreatic neuroendocrine tumors. The lack of information regarding efficacy in bronchial and thymic carcinoids, as well as the scarcity of therapeutic options available, demands the importance of clinical trials that include these patients.

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.

Overdiagnosis of a typical carcinoid tumor as an adenocarcinoma of the lung: a case report and review of the literature

Background

Overdiagnosis of bronchopulmonary carcinoid tumors together with overtreatment can cause serious postoperative consequences for the patient. We report of a patient with a typical bronchopulmonary carcinoid tumor, which was initially misdiagnosed and treated as an adenocarcinoma of the lung. GnrH receptors and the associated Raf-1/MEK/ERK-1/2-pathway are potential targets for analogs in cancer treatment. We suspected a correlation between the lack of tumor growth, application of leuprolide and the Raf-1/MEK/ERK-1/2-pathway. Therefore, we examined GnrH receptor status in the examined specimen.

Case presentation

In 2010 a 77 year-old male patient was shown to have a tumor mass of about 1.7 cm diameter in the inferior lobe of the left lung. Since 2005, this tumor had hitherto been known and showed no progression in size. The patient suffered from prostate cancer 4 years ago and was treated with TUR-P, radiation therapy and the application of leuprolide. We conducted an explorative thoracotomy with atypical segment resection. The first histological diagnosis was a metastasis of prostate cancer with lymphangiosis carcinomatosa. After several immunohistochemical stainings, the diagnosis was changed to adenocarcinoma of the lung. We conducted a re-thoracotomy with lobectomy and systematic lymphadenectomy 12 days later. The tumor stage was pT1 N0 MX G2 L1 V0 R0. Further immunohistochemical studies were performed. We received the results 15 days after the last operation. The diagnosis was ultimately changed to typical carcinoid tumor without any signs of lymphatic vessel invasion. The patient recovered well from surgery, but still suffers from dyspnea and lack of physical performance. Lung function testing revealed no evidence of impairment.

Conclusion

The use of several immunohistochemical markers, careful evaluation of hematoxylin-eosin sections and the Ki-67 labelling index are important tools in discriminating between carcinoids and other bronchopulmonary carcinomas. Although we could not detect GnrH-receptors in the examined specimen, there may be individual differences in expression. GnrH receptor profiles in typical and atypical carcinoids should be scrutinized. This could lead to new therapeutical options, since the GnrH receptor has already been described on atypical carcinoids. Clinically tested drugs such as leuprolide could come to use.

Histology, not Lymph Node Involvement, Predicts Long-Term Survival in Bronchopulmonary Carcinoids

Recently, the incidence of bronchopulmonary carcinoid has increased substantially, whereas survival associated with both subtypes has declined. We reviewed our experience with bronchopulmonary carcinoid to identify factors associated with long-term survival. We reviewed our cancer registry from 1985 to 2009 for all patients undergoing surgical resection for bronchopulmonary carcinoid. Cox regression analysis was used to evaluate prognostic factors. Fifty-two patients met criteria for inclusion. Forty-three patients (82%) presented with typical histology. The likelihood of lymph node metastasis was similar for patients with typical histology and patients with atypical histology. For patients with typical histology, the 5-year survival rates with and without lymph node metastases were 100 per cent and 97 per cent, respectively ( P = 0.420). The overall survival rate for patients with typical histology (97% at 5 years; 72% at 10 years) was significantly better than for patients with atypical histology (35% at 5 years, 0% at 10 years) ( P < 0.001). Univariate and multivariate analyses demonstrated that long-term survival was associated with histology but not lymph node involvement (hazards ratio = 14.6, 95% confidence interval: 1.7, 125.2). Our data suggests that long-term survival is associated with histology, not lymph node involvement. We found tumor histology to be the strongest predictor of long-term survival in patients with pulmonary carcinoid tumors.

Small neuroendocrine lesions in intrathoracic lymph nodes of patients with primary lung adenocarcinoma: real metastasis?

The presence of individual neuroendocrine cells in rare peripancreatic lymph nodes (LNs) suggests that neuroendocrine tumor or nested neuroendocrine cell proliferation can arise in situ from neuroendocrine cells native to any LN. However, it is very difficult to ascertain whether any neuroendocrine lesion in LNs is a primary tumor or a metastasis from adjacent organs. We encountered 4 cases of neuroendocrine proliferation in intrathoracic LNs (ILNs) of patients with primary lung adenocarcinoma. All patients had a single lung mass without mediastinal lymphadenopathy based on computed tomography and positron emission tomography imaging. Mediastinal staging was done by either mediastinoscopy or thoracotomy and none of them had metastasis from adenocarcinoma in any LN. One patient had three ILNs positive for neuroendocrine proliferation measuring 1.7, 1.8, and 4.0 mm, respectively and a minute tumorlet less than 1.0 mm in the lung. Three other patients had small areas of neuroendocrine proliferation no more than 1 mm in single ILN without any lung neuroendocrine lesion. Neuroendocrine cells in ILNs often formed nests of varying size with similar morphology to carcinoid tumorlet in the lung. Small clusters of neuroendocrine cells without any particular pattern were often seen together with these nests. These cells were positive for neuroendocrine markers: synaptophysin, chromogranin, and CD56. They were also positive for CK7 and TTF-1. It is interesting to note, single cells positive for neuroendocrine markers and TTF-1 were identified near or away from these neuroendocrine nests or clusters. These findings suggest that neuroendocrine lesion can be incidentally identified in ILNs. Close clinical follow-up is warranted as metastasis from or synchronous lesions in adjacent organs cannot be excluded.

Bronchial typical carcinoid tumors

The current WHO classification of lung tumors recognizes bronchial typical carcinoid as low-grade neuroendocrine tumors. These tumors grow slowly but can metastasize to regional nodes (4 to 20%) and more rarely to extrathoracic sites. Symptoms are usually related to local compression and obstruction of the bronchial tree. Paraneoplastic syndrome can be present (carcinoid syndrome, Cushing's syndrome, acromegaly). Preoperative diagnosis is usually obtained with bronchoscopic biopsy. Computed tomography and somatostatin receptor scintigraphy are useful in the preoperative staging. Only selected cases can be treated endoscopically with laser resection. The complete surgical resection remains the only therapy with curative intent in the majority of patients. Parenchyma-sparing resections are indicated whenever possible. Overall survival after surgery is excellent (5-year rate, 87 to 100%) with low recurrence rate (2 to 11%). N-status and type of resection seem not to affect prognosis. Local relapse can be treated successfully with surgery, whereas distant metastases have a poor prognosis even after chemotherapy.