Encyclopedia of Pathology

Living Edition
| Editors: J.H.J.M. van Krieken

Myositis Ossificans

Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-28845-1_5436-1



Myositis ossificans (MO) is a benign self-limiting, pseudosarcomatous ossifying lesion that in most cases is secondary to an obvious trauma or minor repetitive trauma.

Clinical Features

  • Age

    It occurs over a broad age range, with a peak in the second and third decades of life (Ackerman 1958; Nuovo et al. 1992; de Silva and Reid 2003).

  • Sex

    There is a predilection for male subjects.

  • Site

    MO can develop at any site, but it occurs more commonly in the skeletal muscles of the lower extremities, especially the thighs and buttocks. Lesions similar to MO can develop in the subcutaneous fat (panniculitis ossificans), in the mesentery (heterotopic mesenteric ossification), in the fascia (fasciitis ossificans), or in the fingers (fibro-osseous pseudotumor of the digits).

  • Treatment

    Once the diagnosis has been reached, surgical treatment is not strictly necessary, unless the lesion causes...

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References and Further Reading

  1. Ackerman, L. V. (1958). Extra-osseous localized non-neoplastic bone and cartilage formation (so-called myositis ossificans): Clinical and pathological confusion with malignant neoplasms. The Journal of Bone and Joint Surgery. American Volume, 40-A, 279–298.CrossRefGoogle Scholar
  2. Bekers, E. M., Eijkelenboom, A., Grünberg, K., Roverts, R. C., de Rooy, J. W. J., van der Geest, I. C. M., van Gorp, J. M., Creytens, D., & Flucke, U. (2018). Myositis ossificans – Another condition with USP6 rearrangement, providing evidence of a relationship with nodular fasciitis and aneurysmal bone cyst. Annals of Diagnostic Pathology, 34, 56–59.CrossRefGoogle Scholar
  3. de Silva, M. V., & Reid, R. (2003). Myositis ossificans and fibroosseous pseudotumor of digits: A clinicopathological review of 64 cases with emphasis on diagnostic pitfalls. International Journal of Surgical Pathology, 11, 187–195.CrossRefGoogle Scholar
  4. Flucke, U., Bekers, E. M., Creytens, D., & van Gorp, J. M. (2018). COL1A1 is a fusion partner of USP6 in myositis ossificans – FISH analysis of six cases. Annals of Diagnostic Pathology, 36, 61–62.CrossRefGoogle Scholar
  5. McCarthy, E. F., & Sundaram, M. (2005). Heterotopic ossification: A review. Skeletal Radiology, 34, 609–619.CrossRefGoogle Scholar
  6. Nuovo, M. A., Norman, A., Chumas, J., & Ackerman, L. V. (1992). Myositis ossificans with atypical clinical, radiographic, or pathologic findings: A review of 23 cases. Skeletal Radiology, 21, 87–101.CrossRefGoogle Scholar
  7. Švajdler, M., Michal, M., Martínek, P., Ptáková, N., Kinkor, Z., Szépe, P., Švajdler, P., Mezencev, R., & Michal, M. (2019). Fibro-osseous pseudotumor of digits and myositis ossificans show consistent COL1A1-USP6 rearrangement: A clinicopathological and genetic study of 27 cases. Human Pathology, 88, 39–47.CrossRefGoogle Scholar

Authors and Affiliations

  1. 1.Department of Translational Research and of New Technologies in Medicine and SurgeryUniversity of PisaPisaItaly