1. CASE REVIEW
강동경희대병원
이한나

2. CASE
58/M
C.C : incidentally detected abnormal finding on chest radiograph

5. 18 months ago

6. A 2.7cm, well-defined nodule in the LLL, no significant interval change. -> d/dx 1) r/o) carcinoid tumor 2) r/o) sclerosing pneumocytoma

7. 26.5 mm .
1 year later

8. 7 years ago
6.5 years ago
16.0 mm
4.5 years ago
18months ago

9. Hospital course Video‑assisted thoracoscopic wedge resection
( )

10. Periodic acid‑Schiff‑positive
Human melanoma black (HMB)‑45

11. Pathologic report
Lung, lower lobe, left, wedge resection: Clear cell tumor 1) size: 2.7 x 2.5 x 2.4 cm 2) mitosis: 1/50 HPFs 3) no necrosis, no atypia 4) clear resection margin [SPECIAL & IMMUNOHISTOCHEMICAL STAIN] SMA, ACTIN (Smooth Muscle) [B03] : negative CD 34 [B03] : positive CHROMOGRANIN A [B03] : negative CK, AE1/AE3 [B03] : negative EMA (Epithelial Membrane Ag) [B03] : negative KI-67 (MIB1) [B03] : about 5% Melanosome (HMB-45) [B03] : positive, focal
　　　S-100 [B03] : positive, focal
　　　SYNAPTOPHYSIN [B03] : negative
　　　TTF-1 (Thyroid Transcription Factor) [B03] :
negative
　　　VIMENTIN [B03] : positive
　　　Melanosome (HMB-45) [B04] : positive, focal
　　　D-PAS [B04] : positive
　　　PAS (Periodic acid Schiff) [B04] : positive

12. Clear cell tumor of the lung (CCTL)
The family of perivascular epithelioid cell tumor (PEComa) (2004 WHO classification)
Very rare benign mesenchymal tumor from perivascular epithelioid cells
Consist with clear cells with a large amount of cytoplasmic PAS‑positive glycogen = sugar tumor
Well-defined margin and homogenous intense enhancement
Rich vascular stroma

13. Surgical resection for diagnosis and curative treatment
Clear cell tumor of the lung (CCTL)
Generally regarded as benign
Malignant behavior : local invasion
Possibility of malignant potential
Necrosis, a mitotic index of > 1 per 50 high‐power fields, marked pleomorphism, and nuclear atypia
Surgical resection for diagnosis and curative treatment

14. Clear cell tumor of the lung (CCTL)
Difficult to identify the interval growth pattern of CCTL.
In our case
Initially gradual interval growth
 Remained 2.7 cm for next 2.5 years
Ann Thorac Surg Feb;91(2):588-91
Gradually grow over five years
1.0cm after 12 months
doubling volume time : 120days