error fine needle aspirationEBUS bronchial washing cytology Cytologic

error ² 세침흡인검사 (fine needle aspiration/EBUS) ² 기관지 세척액 (bronchial washing cytology)

Cytologic features ² Numerous dispersed individual cells forming infrequently small groups and clusters ² Fibrovascular connective tissue (delicate branched capillary blood vessel) ² Tumor cells surrounding, and clinging to, the arborising delicate capillaries ² Bland, uniform, monotonous small cells with minimal or no variation in cell size ² Eccentric round nuclei with fine granular chromatin ² Inconpicuous nucleoli ² Scanty to moderate basophilic cytoplasm ² No pleomorphism, mitosis, necrosis

Differential diagnosis ² Malignant lymphoma ² Small cell carcinoma ² Carcinoid tumor ² Large cell neuroendocrine carcinoma ² Adenocarcinoma

Differential diagnosis ² Malignant lymphoma - no intercellular cohesion - nuclear membrane irregularity - nucleoli+ ² ² Small cell carcinoma Carcinoid tumor Large cell neuroendocrine carcinoma Adenocarcinoma

Differential diagnosis ² Small cell carcinoma - more irregular nuclear contour pyknosis, necrotic debris nuclear molding necrotic background hyperchromasia many naked nuclei and nuclear streaking ² Carcinoid tumor ² Large cell neuroendocrine carcinoma ² Adenocarcinoma

Differential diagnosis ² Large cell neuroendocrine carcinoma - nuclear peomorphism - cohesive cells - fine chromatin - prominent nucleoli - increased mitotic rate - necrotic background ² ² Adenocarcinoma Carcinoid tumor

Differential diagnosis ² Adenocarcinoma -more cytologic atypia -mucin production ² ² Carcinoid tumor Small cell carcinoma Malignant lymphoma Large cell neuroendocrine carcinoma

Mucicarmine stain

TTF-1 CD 56

TTF -1 CD 5 6 Chromogr anin Synaptoph ysin

Cytologic diagnosis Carcinoid tumor

Ki-67

Final diagnosis Atypical carcinoid tumor

Pathologic criteria of neuroendocrine neoplasm of lung Typical carcinoid Atypical carcinoid Small-cell lung cancer Large-cell neuroendocrine carcinoma Light microscopic morphology Neuroendocrine morphology (organoid nesting, palisading, rosettes, trabeculae) Neuroendocrine morphology Small size (less than the diameter of 3 small lymphocytes) 1. Scant cytoplasm 2. finely granular chromatin, absent nuclei or faint nucleoli 1. Neuroendocrine morphology 2. Cytologic features of nonsmall cell carcinoma: large cell size, vesicular, coarse or fine chromatin and/or nucleoli 3. Positive IHC stain for one or more NE markers or neuroendocrine granules by EM, Mitoses per 2 mm 2 <2 2 -10 and/or foci of necrosis >10 Necrosis no Often punctate Frequent, large zone Often large zones Histologic grade Low Intermediated High

Cytologic diagnosis and differential diagnosis of lung carcinoid tumors a retrospective study of 63 Cases with histologic correlation. ² Cancer Cytopathol. 2010 Dec 25; 118(6): 457 -67. ² 63 cases: cytology with corresponding surgical material ² cytology specimens : 49 -FNA specimens 14 -brushings/washings. ² Discordant cases (31 cases, 49%) - Overdiagnosis as small cell carcinoma (4 cases; 6%) adenoid cystic tumor (4 cases; 6%) poorly differentiated carcinoma with NE features (5 cases; 8%) - Misdiagnosis of other lesions as TC (4 cases; 6%)

Cytologic diagnosis and differential diagnosis of lung carcinoid tumors a retrospective study of 63 Cases with histologic correlation. ² The significant morphologic factors : nuclear features, chromatin patterns, nucleoli. ² Nuclear molding and crowding: not discernible features ² Crush artifact : low and high grade ² Ki-67 staining: useful

u Variety of histologic patterns and tumor cells - trabecular, palisading, rosette-like, spindle, glandular, papillary - oncocytic, melanin-rich, mucin-producing, signet ring , clear, acinic-like, pleomorphic, bizarre u Stromal component: psammomatous, ossification, amyloid deposition