Soft tissue
Smooth muscle
Leiomyoma
Author: Vijay Shankar, M.D.
Last author update: 1 November 2012
Last staff update: 20 March 2024 (update in progress)
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Leiomyoma 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 April 27th, 2024.
Definition / general
- Bland smooth muscle tumor without mitotic figures (eMedicine: Leiomyoma [Accessed 26 July 2023])
- 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
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:
- Leiomyosarcoma:
- More cellular, infiltrative, pleomorphic
- Mitotic activity and coagulative tumor cell necrosis
- Myolipoma:
- Prominent fatty change
