KCP-815 서울대학교 병원 전공의 최은오

History 52/M 특별한 병력은 없고 30갑년의 흡연력이 있음 15일전부터 흉통이 있어 타병원에서 시행한 흉부영상에서 흉막 삼출 및 폐종괴가 발견됨 CT: 우중엽에 장경 1cm크기의 경계가 좋은 종괴, 우측 흉강 하부에 국한된 흉막 삼출이 동반되어 있었음 PET/CT: 종괴에 대한 FDG흡수 증가 종괴에 대한 세침 흡인 검사의 도말 슬라이드

Cytologic features Background Proteinaceous fluid with many hemosiderin or anthracotic pigment-laden macrophages Cellularity Moderate Architecture Scattered epithelial cell clusters exhibiting papillary, sometimes ill-formed acini, rosette-like pattern Cell Small to medium in size Round or columnar cells Relatively bland-looking, but occasionally large cells with mild to moderate nuclear pleomorphism and nuclear hyperchromasia Cytoplasm Small to moderate amount of cytoplasm Nucleus Mostly, uniform round to oval nuclei Smooth to irregular nuclear contour Fine, stippled chromatin pattern Inconspicuous nucleoli Intranuclear inclusion

Differential diagnosis Adenocarcinoma with lepidic pattern Carcinoid tumor Papillary adenoma Sclerosing hemangioma

Clinical and radiologic features ADC with lepidic pattern Carcinoid tumor Sclerosing hemangioma Papillary adenoma Less commonly associated with smoking than other types of NSCLC Less than 4% of NSCLCs May present as single or multiple nodules 1-2% of all lung tumors From childhood to the ninth decades (mean age: 47years) Similar frequencies in men and women Mostly, central masses causing bronchial obstruction Marked female predilection (80%) Peak incidence in fifth decade Mostly, solitary lesion Multifocal in 4% of cases Rare incidence Males appear to predominate Between 7 and 60 years Peripheral parenchymal lesion

ADC with lepidic pattern Carcinoid tumor Sclerosing Hemangioma Papillary adenoma Highly cellular aspirates with bland cuboidal to columnar cells in papillary clusters or flat sheets Round to oval nuclei of uniform size Nuclear membrane folds and grooves Intranuclear pseudoinclusions Cells occur singly and in clusters Stripped nuclei Small plasmacytoid cells and/or spindled cells Scan to moderate cytoplasm Stippled granular chromatin Papillary clusters of bland-looking mononuclear cells Hyalinized stromal tissue fragments Some scattered epithelial cells with nuclear pleomorphism and intranuclear inclusions Hemosiderin-laden macrophages in the background Epithelial cell clusters of sheet or papillary pattern Round to oval nuclei Mild nuclear atypia Fine chromatin pattern, sometimes small nucleoli Scanty cytoplasm, high N/C ratio

Cytologic diagnosis MICRO (2 pap) Lung, aspiration cytology: Adenocarcinoma with lepidic pattern