ABSTRACT: We performed renal biopsy in three cases complicated by myeloproliferative neoplasms (MPN). Although several cases of glomerulonephritis associated with MPN have been reported, the etiologies of the renal disorders were not established (Plomley et al., Aust NZ J Med, 13:125-129, 1983; Sharma et al., Nephron, 69:361, 1995; Kanauchi et al., Intern Med, 33:36-40, 1994; Kasuno et al., Nephrol Dial Transplant, 12:212-215, 1997; Au et al., Am J Kid Dis, 34:889-893, 1999; Kosch et al., Nephrol Dial Transplant, 15:1710-1711, 2000; Oymak et al., Nephron, 86:346-347, 2000; Chun et al., Am J Nephrol, 20:344-346, 2000; Chung et al., Am J Nephrol, 22:397-401, 2002; Asaba et al., Clin Exp Nephrol, 7:296-300, 2003; Haraguchi et al., Clin Exp Nephrol, 10:74-77, 2006; Saigusa et al., J Nephrol, 19:656-658,
