[Histological and ultrastructural features of giant cell myocarditis: report of 3 cases].
OBJECTIVE
To identify clinical and pathological features of giant cell myocarditis.


METHODS
Clinical presentation and follow-up data of three patients with giant cell myocarditis were collected.Gross, histopathological, immunohistological and ultrastructural findings of extransplantated hearts of the patients were documented.


RESULTS
Grossly, multifocal involvement of the myocardium with variably dilated cardiac chambers were observed in all 3 cases.Histological examination revealed pronounced focal inflammatory infiltrates with multinucleated giant cells. Multinucleated giant cells were positive for CD68 and CD11b immunostains but were negative for CD163 in all cases. Transmission electron microscopy showed that the multinucleated giant cells derived from fusion of several macrophages with adherent lymphocytes and secretary cells. Clinically, the overall patient condition improved in all three cases after heart transplantation.One patient experienced acute cellular rejection (2R level) 4 months after transplantation, but recovered after treatment. One patient developed multinucleated giant cells observed in heart biopsy two weeks after transplantation.


CONCLUSIONS
Giant-cell myocarditis is a rare disease of adult, and cardiac transplantation could improve the clinical outcome. Multinucleated giant cell in the myocarditis lesions were derived from macrophages, likely participating in the immune response. Endomyocardial biopsy is important for the diagnosis of giant cell myocarditis.
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
Yang
Y
Sun
E-mail: zhaohongfw@aliyun.com.
Hong
H
Zhao
Laifeng
L
Song
Qingzhi
Q
Wang
Yan
Y
Chu
Jie
J
Huang
Shengshou
S
Hu
D000208:Acute Disease; D000328:Adult; D001706:Biopsy; D015726:Giant Cells / Q000473:pathology* / Q000648:ultrastructure*; D016027:Heart Transplantation; D006801:Humans; D008214:Lymphocytes / Q000473:pathology; D008264:Macrophages / Q000473:pathology; D046529:Microscopy, Electron, Transmission; D009205:Myocarditis / Q000473:pathology*; D009206:Myocardium / Q000473:pathology* / Q000648:ultrastructure*