title: Myositis ossificans and fibroosseous pseudotumor of digits: a clinicopathological review of 64 cases with emphasis on diagnostic pitfalls.
abstract: Myositis ossificans (MO) and fibroosseous pseudotumor of digits (FP) are pseudotumoral mimics of malignancy. A review of 50 cases of MO and 14 cases of FP showed that a malignant diagnosis was suggested by referring pathologists in 23% of MO and 9% of FP. The most common misdiagnosis was osteosarcoma. Awareness of the spectrum of clinicopathological features of MO and FP will help pathologists avoid misdiagnoses. A comparison of the clinicopathological features of MO and FP showed that most features were similar, but FP involved an older age group (p<0.001). MO showed a statistically significant higher tendency to contain fibrinous material (p=0.007), edematous lymphangioma-like areas (p=0.013), and cartilage (p=0.017) and FP to contain excessive immature osteoid (p=0.029). These differences may be related to the site of occurrence.
authors.affiliation: University Department of Pathology/Scottish Bone Tumour Registry, Western Infirmary, Glasgow, UK.
authors.forename: M V C
authors.initials: MV
authors.lastname: de Silva
authors.forename: R
authors.initials: R
authors.lastname: Reid
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005385:Fingers / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009221:Myositis Ossificans / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D012516:Osteosarcoma / Q000473:pathology; D014057:Tomography, X-Ray Computed