Endobronchial carcinoid tumor combined with pulmonary non-tuberculous mycobacterial infection: report of two cases

We report here two cases of endobronchial carcinoid tumor complicated with pulmonary infection with non-tuberculous mycobacteria (NTM). Case 1 was an 81-year-old woman with the left lower lobe atelectasis. Bronchoscopy showed complete obstruction of the left basal bronchus by a tumor and a sleeve lower lobectomy with mediastinal lymph node dissection was performed. Pathological examination showed typical carcinoid located in the left basal bronchus and many caseous granulomas containing mycobacteria in the lung parenchyma distal to the bronchus. Bacterial examinations of sputum and gastric juice after the operation showed a growth of Mycobacterium kansasii. Case 2 was a 50-year-old woman with the atelectasis of the left upper division. Bronchoscopy showed complete obstruction of the left upper division bronchus by a tumor and a left upper lobectomy with mediastinal lymph node dissection was performed. Pathological examination showed typical carcinoid located in the left upper division bronchus and many caseous granulomas in the lung parenchyma distal to the bronchus. The Ziehl-Neelsen stain showed many mycobacteria in these granulomas and they were identified as Mycobacterium avium by PCR analysis. Although NTM are not well recognized as possible pathogens of pulmonary infection related to bronchial obstruction by endobronchial carcinoma, our experiences rouse a caution to consider NTM as potential pathogens. We also discuss the possible mechanisms responsible for the specific relationship between carcinoid tumor and TNM.     

Peripheral pulmonary carcinoid tumors.

The light microscopic and ultrastructural features of five asymptomatic peripheral carcinoids presented as distinct pulmonary solitary nodules are described. By conventional microscopy the tumors displayed a variety of histologic patterns, the most unusual one showing tumor cells embedded in a richly vascular hyalinized stroma and forming papillary structures or cystic spaces lined by low cuboidal cells which ultrastructurally bore a strong resemblance to intermediate or transitional forms between types I and II pneumocytes. A striking feature of these tumors was their rich vasculature associated with a marked perivascular sclerosis composed of basement membrane-like material and collagen fibrils most likely produced by the increased numbers of pericytes surrounding these sclerotic vessels. The clinical implications, biologic behavior, and association of these tumors with other pulmonary neoplasms are also discussed.     

Unusual lesions of the parotid gland.

Ten unusual cases of parotid tumors are added to the literature from a series of 318 consecutive parotidectomies. These 10 cases are: 3 branchial cleft cysts; a lipoma; a lymphangioma; a hemangiopericytoma; a Boeck sarcoid; a metastasizing basal cell carcinoma; a lymphoma of the parotid; and a metastatic adenocarcinoma from the left breast to the right parotid. The lymphoma, Case 1, is also an example of some other cranial nerve taking over the function of the facial nerve when it is destroyed in early childhood. Though most tumors of the parotid gland are of the mixed type, many suprising findings are possible. The pathology report may be the first clue to a hidden systemic disease.     

Classification of small cell lung cancer and pulmonary carcinoid by gene expression profiles.

Small cell lung cancer is a common type of lung cancer that is generally classified within the spectrum of neuroendocrine lung neoplasms. Using high-density cDNA arrays, we profiled gene expression of small cell lung cancers and compared these expression profiles to those of normal bronchial epithelial cells and pulmonary carcinoids, which are classified as benign neuroendocrine tumors. We found the overall expression profiles of two small cell lung cancer cell lines, two microdissected tissue samples of primary small cell lung cancer, and cultured bronchial epithelial cells to be relatively similar to one another, with an average Pearson correlation coefficient for these comparisons of 0.63. However, we found the expression profiles of small cell lung cancers (and bronchial epithelial cells) to be surprisingly dissimilar to those of two samples of pulmonary carcinoid tumors, with an average correlation coefficient for these comparisons of 0.20. We then compared the pulmonary carcinoid expression profiles to those of two samples of infiltrating astrocytic brain cancers (oligodendroglioma and high-grade astrocytoma) and found similarity of gene expression among these four samples (average correlation coefficient, 0.57). These gene expression profiles suggest that small cell lung cancers are closely related to (and possibly derived from) epithelial cells, and that pulmonary carcinoids are related to neural crest-derived brain tumors. More generally, our results suggest that broad profiles of gene expression may reveal similarities and differences between tumors that are not apparent by traditional morphological criteria.     

Endobronchial ultrasound-guided biopsy of coin lesions

Evaluation of: Dooms CA, Verbeken EK, Becker HD, Demedts MG, Vansteenkiste JF: Endobronchial ultrasonography in bronchoscopic occult pulmonary lesions. J. Thorac. Oncol. 2, 121-124 (2007). Transbronchial biopsy (TBB) for solitary pulmonary nodules is usually performed under fluoroscopic guidance, but the diagnostic yield depends on lesion size and varies widely. An alternative guidance technique, endobronchial ultrasound (EBUS), also allows for the visualization of pulmonary nodules. Dooms and colleagues evaluated the yield of EBUS-guided TBB in a series of consecutive patients with a bronchoscopic-occult pulmonary lesion. The mean diameter of the lesions was 36.6 mm. A histologic diagnosis upon TBB was obtained in 84% of patients. However, the diagnostic yield was very poor for lesions less than 20 mm in diameter. The group concluded that EBUS-guided TBB is effective for localizing and diagnosing bronchoscopic-occult pulmonary masses.     

Ultrastructure of carcinoid of the lung

The paper deals with the electron microscopic analysis of samples of 40 lung tumors histologically diagnosed as carcinoid or malignant carcinoid. The study group was shown to include tumors differing in cell ultrastructure and histological patterns. Three basic tissue patterns formed by 3 specific cellular types were identified: epithelioid, sarcomatoid and symplastic one. Tumors usually showed a combination of the said types with the predominance of one of them. Tumors exhibiting only one morphologic pattern of neurosecretory granules were much more rare. All the neoplasms studied were of neuroendocrine nature.     

Treatment of carcinoid of the lung

PURPOSE OF REVIEW: Pulmonary carcinoids are rare neuroendocrine malignancies that comprise 2% of primary lung tumors. During the last few years, important information has appeared in the literature in relation to the histopathology, molecular biology, biologic behavior, and treatment of these tumors. RECENT FINDINGS: Histologic subclassification of carcinoid tumors into atypical and typical is of paramount importance. Genetic changes in these subclasses are now well-known and are helpful for the differentiation. The biologic behavior of typical and atypical carcinoids is completely different, and treatment planning is based on this information. Surgery is the treatment of choice for localized carcinoid tumors and includes lymphadenectomy. In metastatic disease, chemotherapy with a cisplatin-based or streptozotocin-based combination is moderately effective. Palliation with biotherapy including interferon, somatostatin analogs, and octreotide is encouraging. Liver embolization is an option for symptomatic liver involvement. SUMMARY: Pulmonary carcinoids are rare tumors, and our understanding of their histopathology and biologic behavior are the most important factors for treatment planning. Surgery is the treatment of choice for cure.