Soft tissue
Smooth muscle
Leiomyoma
Leiomyoma of deep soft tissue
Author: Vijay Shankar, M.D.
Topic Completed: 1 November 2012
Minor changes: 10 September 2020
Copyright: 2002-2020, PathologyOutlines.com, Inc.
PubMed Search: Leiomyoma of deep soft tissue
Table of Contents
Definition / general | Epidemiology | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Cytology description | Positive stains | Negative stains | Differential diagnosisCite this page: Shankar V. Leiomyoma of deep soft tissue. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissueleiomyomadeep.html. Accessed September 21st, 2020.
Definition / general
- Very rare tumor of deep subcutis or skeletal muscle of extremities (Stanford University) or retroperitoneum (described below)
- By definition, is distinct from uterus
Epidemiology
- Tumors of deep somatic soft tissue affect males and females equally (Am J Surg Pathol 2001;25:1134)
- Tumors of retroperitoneum (described below) almost always occur in women
- Can rarely occur in children
Case reports
- 32 year old man with carpal tunnel syndrome due to atypical deep soft tissue leiomyoma (World J Surg Oncol 2007;5:92)
Treatment
- Excision; rarely recurs
Clinical images
Images hosted on other servers:
Hand mass:
intraoperative and
gross specimen
Gross description
- Well circumscribed, gray-white
- Usually large at presentation, up to 15 cm
- May have myxoid change
Microscopic (histologic) description
- Fascicles of normal appearing smooth muscle with eosinophilic cytoplasm
- Nuclei are bland and uniform, blunt ended, cigar shaped
- May have dystrophic calcification, degenerative nuclear changes or necrobiotic nodules resembling giant rosettes
- Hyalinization and fatty differentiation can also be seen rarely
- No / minimal atypia
- No / rare mitotic figures (Am J Surg Pathol 1994;18:576); < 1 per 50 HPF
- No necrosis
Cytology description
- Hypocellular smears, with scattered clusters of spindle cells (Diagn Cytopathol 1997;16:326)
- Clustered cells have syncytial appearance
- Bland nuclei have spindled appearance with rounded ends, condensed chromatin
- Usually no necrosis or inflammation
- No mitotic figures
Positive stains
- Actin, desmin, h-caldesmon
- ER and PR in retroperitoneal tumors
Negative stains
Differential diagnosis
- Benign metastasizing leiomyoma: see Am J Surg Pathol 1998;22:897
- Myolipoma: prominent fatty change
