Soft tissue
Smooth muscle
Leiomyoma
Author: Vijay Shankar, M.D.
Last author update: 1 November 2012
Last staff update: 25 January 2023
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Leiomyoma[TI] general pathology
Table of Contents
Definition / general | Terminology | Epidemiology | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Shankar V. Leiomyoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueleiomyoma.html. Accessed February 3rd, 2023.
Definition / general
- Bland smooth muscle tumor without mitotic figures (eMedicine)
- Includes leiomyoma of deep soft tissue and retroperitoneum
Terminology
- Cutaneous and pilar tumors are described in the Skin chapter
- Some tumors previously considered to be leiomyomas are actually GI stromal (GIST) tumors
- See also colon-tumor, esophagus, uterus chapters
Epidemiology
- Skin and subcutis; also deep soft tissue, uterus (most common neoplasm in women)
- Patients with multiple cutaneous leiomyomas may have autosomal dominant disorder (described under Cutaneous leiomyoma)
Case reports
- 32 year old man with carpal tunnel syndrome due to atypical deep soft tissue leiomyoma (World J Surg Oncol 2007;5:92)
- 34 year old man with sickle cell thalassemia and ossified leiomyoma (J Cutan Pathol 2005;32:696)
- 59 year old woman with finger lesion (Chang Gung Med J 2004;27:134)
Gross description
- Deep tumors are well circumscribed, gray-white; usually large at presentation, up to 15 cm; may have myxoid change
Gross images
Contributed by @Andrew_Fltv on Twitter
Leiomyoma of deep soft tissue
Images hosted on other servers:
Myxoid subcutaneous tumor
Microscopic (histologic) description
- Bundles or fascicles of spindled cells with eosinophilic and possibly fibrillary cytoplasm
- Nuclei are blunt ended and elongated with fine chromatin, indistinct nucleolus and variable cytoplasmic vacuole at one end
- Minimal atypia
- Few mitotic figures
- No coagulative tumor necrosis
Microscopic (histologic) images
AFIP images
Oblong nuclei have rounded ends
Bundles of elongate
cells with eosinophilic
cytoplasm and oblong nuclei
Images hosted on other servers:
Calcified leiomyoma
Positive stains
- Desmin, alpha smooth muscle actin
- H-caldesmon, calponin, muscle specific actin, myosin
- ER and PR for uterine tumors
Differential diagnosis
- Angiomyolipoma: usually prominent vascular and lipomatous component
- Benign metastasizing leiomyoma: see Am J Surg Pathol 1998;22:897
- Leiomyosarcoma: more cellular, infiltrative, pleomorphic; mitotic activity and coagulative tumor cell necrosis
- Myolipoma: prominent fatty change
