Fig. 3
From: Intra-articular nodular fasciitis: a rare lesion case report and an updated review of the literature
The pathological findings of the intra-articular lesion. a. Low-magnification (haematoxylin and eosin, original magnification × 40) image showed the unencapsulated and well-circumscribed tumour. b. The tumour consists of a bland fibroblastic proliferation arranged in irregular fasciitis with tissue-culture-like appearance. Extravasated erythrocytes, shown by arrows, are presented throughout the lesion (haematoxylin and eosin, original magnification × 200). c. The stroma varies from focally myxoid with microcyst formation to collagenous (haematoxylin and eosin, original magnification × 200). d. Ki-67 was 10% (original magnification × 100). e. Patchy positive for smooth muscle actin (original magnification × 200). f. Negative for desmin (original magnification × 200) g. Negative for S100 (original magnification × 200). h. Negative for CK(AE1/AE3) (original magnification × 200) in lesion cells