1. KCP-780 울산대학교 서울아산병원 전공의 노진

2. Patient History 72/M 경부 종괴 양측 갑상선 –2.0cm, 1.5cm 석회화를 동반한 저음영의 종괴 – 다양한 크기의 여러 결절 양측 경부 level Ⅲ, Ⅳ, Ⅴ 림프절 비대

4. Cell clusters with irregular shape

5. Occasional spindle cells

6. Scattered single cells

7. Intratumoral neutrophilic infiltration

8. Intracytoplasmic eosinophilic materials

9. Multinucleated giant cells

10. Cells with vacuolated cytoplasm

11. Cytologic findings Cell clusters with irregular shape Occasional spindle cells and scattered single cells Severe pleomorphism Enlarged nuclei and macronucleoli Intracytoplasmic eosinophilic materials and vacuolization Intratumoral neutrophilic infiltration

12. Differential diagnoses Metastasis from thyroid gland Metastasis from other organs ( and metastasis to thyroid gland)

13. Differential diagnoses Metastasis from thyroid gland Metastasis from other organs ( and metastasis to thyroid gland)

14. Thyroid gland –Anaplastic thyroid carcinoma Single huge neck mass Rapidly enlarging and very symptomatic neck mass Extensive local invasion beyond the thyroid gland

15. Differential diagnosis Metastasis from thyroid gland Metastasis from other organs ( and metastasis to thyroid gland)

16. Metastasis to thyroid gland –Kidney > Colon, Lung, Breast > Malignant melanoma

17. Malignant melanoma –Large cell with abundant cytoplasm –Round eccentric nuclei with prominent nucleoli –Multinucleation and variable degrees of vacuolization –Presents singly and in clusters –Cell-in-cell engulfment –Cytoplasmic melanin –Intracytoplasmic eosinophilic materials? –Intratumoral neutrophilic infiltration?

18. Pulmonary non-small cell carcinoma –Extreme pleomorphism –Tumor giant cell morphology –Extreme vacuolization –Intratumoral neutrophilic infiltration –Mucin? –Cell ball –Perinucleolar chromatin clearing

19. Renal cell carcinoma, high grade –Large cells with abundant clear or eosinophilic granular or vacuolated cytoplasm –Prominent nucleoli : round central (single or multiple), brightly eosinophilic –Magenta-staining basement membrane-like materials –Intratumoral neutrophilic infiltration

20. Diagnosis Lymph node (left neck), fine needle aspiration biopsy: - Metastatic poorly differentiated carcinoma, favor kidney or lung origin.