Proliferative Myositis
Original Editors - Billie Rehberg from Bellarmine University's Pathophysiology of Complex Patient Problems project.
Lead Editors - Your name will be added here if you are a lead editor on this page. Read more.
Definition/Description[edit | edit source]
Proliferative myositis (PM) is a benign tumor which grows in skeletal muscle[1]. It is usually 3-4 cm in diameter[2], and is often mistaken for sarcomas (especially rhabdomyosarcoma)[3]. While etiology is unknown, it may result from injury to the muscle, fascia, or vasculature (resulting in ischemia) of the associated area[4]. PM generally presents in the upper extremity or trunk regions[2]. Median age of onset is 50 years[5], with rare cases reported in children[2].
Prevalence
[edit | edit source]
Characteristics/Clinical Presentation[edit | edit source]
- Rapidly enlarging, solid tumor within skeletal muscle
- Localized inflammation
- No lymph node enlargement
- No significant laboratory results
Associated Co-morbidities[edit | edit source]
add text here
Medications[edit | edit source]
add text here
Diagnostic Tests/Lab Tests/Lab Values[2][edit | edit source]
Proliferative Myositis is diagnosed based on biopsy. The following list, taken directly from the Stanford University School of Medicine page on PM, are histologic and immunologic characteristics of PM which are used in its diagnosis:
Relatively normal muscle fibers separated by expanded myxoid connective tissue
o Produces distinctive checkerboard pattern
o No evidence of muscle damage
No sarcolemmal proliferation
No multinucleation
No nuclear enlargement
No necrosis
Connective tissue space between fibers contains reactive cells resembling those seen in nodular fasciitis and proliferative fasciitis
o Spindled and stellate fibroblasts and myofibroblasts
Vesicular nuclei
No cytologic atypia
o Ganglion-like cells
Characteristic feature of this process
Large round regular nuclei
Occasional binucleate and trinucleate cells may be seen
Prominent nucleoli
Dispersed chromatin
Basophilic to amphophilic cytoplasm
May be clustered and may mold each other
o Mitotic figures frequent
No atypical mitotic figures
Etiology/Causes[edit | edit source]
While etiology is unknown, PM may result from injury to the muscle, fascia, or vasculature (resulting in ischemia) of the associated area[4].
Systemic Involvement[edit | edit source]
add text here
Medical Management (current best evidence)[edit | edit source]
Surgical excision (recurrence following excision is rare)
Physical Therapy Management (current best evidence)[edit | edit source]
add text here
Alternative/Holistic Management (current best evidence)[edit | edit source]
add text here
Differential Diagnosis[5][3][2][edit | edit source]
- Myositis Ossificans
- Neoplasms (especially rhabdomyosarcomas)
- Proliferative fasciitis
- Nodular fasciitis
- Fibromatosis
- Ganglioneuroblastoma or ganglioneuroma
Case Reports/ Case Studies[edit | edit source]
add links to case studies here (case studies should be added on new pages using the case study template)
Resources
[edit | edit source]
add appropriate resources here
Recent Related Research (from Pubmed)[edit | edit source]
see tutorial on Adding PubMed Feed
References[edit | edit source]
see adding references tutorial.
- ↑ Fauser C, Nahrig J, Niedermeyer H, Arnold W. Proliferative myositis: a rare pseudomalignant tumor of the head and neck. Archives of Otolaryngology - Head & Neck Surgery [serial on the Internet]. (2008, Apr), [cited March 16, 2011]; 134(4): 437-440. Available from: CINAHL with Full Text.
- ↑ 2.0 2.1 2.2 2.3 2.4 Stanford University. Proliferative Myositis. Available at http://surgpathcriteria.stanford.edu/softfib/proliferative_myositis/printable.html. Accessed April 4, 2011
- ↑ 3.0 3.1 Meis J, Enzinger F. Proliferative fasciitis and myositis of childhood. The American Journal Of Surgical Pathology [serial on the Internet]. (1992, Apr), [cited March 16, 2011]; 16(4): 364-372. Available from: MEDLINE.
- ↑ 4.0 4.1 Dent C, DeBoom G, Hamlin M. Proliferative myositis of the head and neck. Report of a case and review of the literature. Oral Surgery, Oral Medicine, And Oral Pathology [serial on the Internet]. (1994, Sep), [cited March 16, 2011]; 78(3): 354-358. Available from: MEDLINE.
- ↑ 5.0 5.1 Mulier S, Stas M, Delabie J, Lateur L, Gysen M, De Wever I, et al. Proliferative myositis in a child. Skeletal Radiology [serial on the Internet]. (1999, Dec), [cited March 16, 2011]; 28(12): 703-709. Available from: MEDLINE.