Atypical decubital fibroplasia associated with bizarre parosteal osteochondromatous proliferation (Nora's reaction).

We describe recurring bizarre parosteal osteochondromatous proliferation (Nora's reaction) associated with atypical decubital fibroplasia in the region of the greater trochanter of the femur in a 52-year-old man. We hypothesize that these two recently introduced entities may represent two forms of tissue response to injury (ischemia) inducing proliferative reaction of bone and cartilage in the vicinity of periosteum, and necroses with hyperplastic granulation tissue and myxoid stroma in the subcutaneous tissues.