Atypical carcinoid tumors of the lung

Large cell neuroendocrine carcinoma of the thymus

“…Neuroendocrine tumours in the lung were originally placed in one of three categories: typical carcinoid, atypical carcinoid and small cell carcinoma 3 .…”

Clinicopathological and immunohistochemical analysis of spindle-cell carcinoid tumour of the lung

“…In series analyses of neuroendocrine carcinomas, SCCTs have been observed to comprise 4.5-30.2% of all carcinoid tumours. 1,9,14,22,26 Clinically, SCCTs are peripherally located asymptomatic tumours showing clinical behaviour ranging from extremely indolent 8,9,16,21,23 to more aggressive 10,13 than non-spindle cell carcinoid tumours. Histologically, SCCTs are arranged in a vague organoid pattern with sharply circumscribed borders and are composed of elongated spindle cells with scant to moderate amounts of cytoplasm and poorly defined cell borders.…”

Bronchial carcinoid with multiple aerogenous implanted foci

“…The present case also involved lymph node metastasis, though the tumor cells showed no atypical features. Arrigoni et al [6] described in their review of 216 bronchial carcinoids that 70% of 23 atypical carcinoids developed metastasis, while only 5.6% of the 178 usual carcinoids did [6]. The absence of such atypical features does not indicate that the tumor is necessarily a benign one [22,23].…”

“…HE x500. 6). The tumor cells arranged in a pseudoacinar or pseudoglandular pattern showed tall, columnar cells with basally placed nuclei.…”

“…Bronchial carcinoid is a low-grade malignant tumor originating from the bronchial gland and bronchiolar epithelium (1)(2)(3)(4)(5). Metastasis occurs in approximately 10% of bronchial carcinoid, and a disproportionate number of such metastases may be associated with the tumors showing atypical features [ 1,5,6].…”