Leiomyoma of deep soft tissue

Soft tissue
Smooth muscle
Leiomyoma of deep soft tissue

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 29 September 2016, last major update November 2012

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Leiomyoma of deep soft tissue

Table of Contents

Cite this page: Leiomyoma of deep soft tissue. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissueleiomyomadeep.html. Accessed September 25th, 2017.

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

S100

Differential diagnosis

Benign metastasizing leiomyoma: see Am J Surg Pathol 1998;22:897
Myolipoma: prominent fatty change