Definition
• On biopsy, a lymphocytic endocardial infiltration of mature small lymphocytes that may extend into underlying myocardium; also seen in epicardium and myocardium when the whole heart is examined
Pathogenesis
• Unknown
Clinical features
Epidemiology
• In the literature the incidence ranges from 8% to 79% depending on centers conducting the study
Presentation
• Usually incidental finding when endomyocardial biopsy is done for surveillance or evaluation of symptomatic rejection
Prognosis and treatment
• Often disappears a few weeks or months after transplantation
Pathology
Histology
• Quilty A: endocardial infiltrate of mature small lymphocytes, often associated with small capillaries; the lesion does not invade the underlying myocardium
• Quilty B: essentially same as Quilty A, except for the presence of extension into myocardium, which may be associated with myocardial damage
Immunopathology/special stains
• CD21 immunostain is positive in the center of larger Quilty lesions, indicating a follicular dendritic cell network
Main differential diagnosis
• Acute cellular rejection: the lymphocytes are larger; eosinophils may be present, sometimes with associated myocyte damage; may extend into endocardium; few capillaries; no CD21 staining
• Site of previous biopsy: organizing fibrin with few inflammatory cells
Fig 1 Quilty lesion. Quilty A lesion seen as a subendocardial collection of small lymphocytes and associated small capillaries.
Fig 2 Quilty lesion. Quilty B lesion is a collection of small mature-appearing lymphocytes involving myocardium and associated with multiple capillaries and myocyte damage (A); an immunostain for CD21 (showing dendritic cell network) is positive in its center (B).