Clear cell tumour of the lung (sugar tumour)

This is a rare tumour of the lung. Rarely, similar tumours have been described at a wide range of extrapulmonary sites. Clear cell tumour of the lung is thought to be one of a family of tumours with the features of so-called perivascular epithelioid cells (PEC)2. Rarely, a combination of clear cell tumour, lymphangioleiomyomatosis multifocal multinodular pneumocyte hyperplasia and tuberous sclerosis has been reported3.

Epidemiology

The age range is very wide, including children. Only very rarely is there an association with tuberous sclerosis

Radiology

Lesions are usually solitary and peripheral.

Histopathology

Cells have abundant clear or eosinophilic cytoplasm, usually but not always containing glycogen7. Cell borders are distinct. There are thin-walled sinusoidal vessels7. Mitoses are usually absent and necrosis is rare1. Cases with a component of adipocytes have been reported2.

Immunohistochemistry

HMB-45	positive, 7/95, 4/56, 2/27
HMB-50	positive, 6/95
Cathepsin B	5/56
alpha-1-antitrypsin	4/56
synaptophysin	may be focally positive
CD57	may be focally positive
NSE	may be focally positive, 9/9(focal)5, 1/56
S-100	may be focally positive, 9/9(focal)5, 3/56
CD34	may be focally positive, 2/27
HAM56	2/56
Factor VIIIRA	0/27
Factor XIIIa	2/56
Cytokeratin	0/84, 0/5(AE 1, AE 3, or CAM 5.2)6, 0/27
EMA	0/84
CEA	0/56
Chromogranin	0/84, 0/56
Synaptophysin	1/8(focal)4, 0/56
CD57	1/8(focal)4
Vimentin	0/84, 4/56, 2/27
SMA	0/27
GFAP	0/95, 0/56
alpha-1-antichymotrypsin	0/56

Ultrastructure

There is abundant glycogen1. Premelanosomes may be seen5.

Differential diagnosis

primary clear cell carcinoma: negative for HMB-45 and positive for cytokeratins.
metastatic renal cell carcinoma
carcinoid tumour
granular cell tumour: positive for S-100 but not for HMB-45 and lacks abundant glycogen.
metastatic melanoma and clear cell sarcoma: also positive for HMB-45 but show nuclear atypia.
sclerosing haemangioma
haemangiopericytoma

Prognosis

Benign: cured by local resection. There are rare reports of malignant metastasizing cases1.

References

Diagnostic histopathology of tumors. Edited by CDM Fletcher. 2nd edition. Churchill Livingstone. Page 195.

0 Tumours of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumours. IARC Press 2004.

1 Andrion A, Mazzucco G, Gugliotta P, et al. Benign clear cell (sugar) tumor of the lung. A light microscopic, histochemical, and ultrastructural study with a review of the literature. Cancer 1985; 56:2657-63

2 Bonetti F, Pea M, Martignoni G, et al. Clear cell ("sugar") tumor of the lung is a lesion strictly related to angiomyolipoma--the concept of a family of lesions characterized by the presence of the perivascular epithelioid cells (PEC). Pathology 1994; 26:230-6

3 Flieder DB,Travis WD. Clear cell "sugar" tumor of the lung: association with lymphangioleiomyomatosis and multifocal micronodular pneumocyte hyperplasia in a patient with tuberous sclerosis. Am J Surg Pathol 1997; 21:1242-7

4 Gaffey MJ, Mills SE, Askin FB, et al. Clear cell tumor of the lung. A clinicopathologic, immunohistochemical, and ultrastructural study of eight cases. Am J Surg Pathol 1990; 14:248-59

5 Gaffey MJ, Mills SE, Zarbo RJ, et al. Clear cell tumor of the lung. Immunohistochemical and ultrastructural evidence of melanogenesis. Am J Surg Pathol 1991; 15:644-53

6 Gal AA, Koss MN, Hochholzer L, et al. An immunohistochemical study of benign clear cell ('sugar') tumor of the lung. Arch Pathol Lab Med 1991; 115:1034-8

7 Lantuejoul S, Isaac S, Pinel N, et al. Clear cell tumor of the lung: an immunohistochemical and ultrastructural study supporting a pericytic differentiation. Mod Pathol 1997; 10:1001-8

8 Hornick JL,Fletcher CD. PEComa: what do we know so far? Histopathology 2006; 48:75-82

This page last revised 1.2.2006.