Leiomyoma
A leiomyoma is a very common benign tumour of smooth muscle. Leiomyomas fit into the soft tissue group of lesions. They are extremely common in the uterus. They may also be seen in the skin.
General
- Benign.
Cutaneous leiomyomas
Uterine leiomyoma
Main article: Uterine leiomyoma
- Often called "fibroids".
- Extremely common... 40% of women by age 40.
- Can be a cause of AUB (abnormal uterine bleeding).
- Large & multiple leiomyomas are associated with infertility.
Gross
- Sharply circumscribed.
- Gray-white.
- Whorled appearance.
Factors that raise concern for leiomyosarcoma:
- Haemorrhage.
- Cystic degeneration.
- Necrosis.
Microscopic
Features:
- Spindle cells arranged in fascicles.
- Fascicular appearance: adjacent groups of cells have their long axis perpendicular to one another; looks somewhat like a braided hair that was cut.
- Whorled arrangement of cells.
- +/-Medium-sized artery seen at the periphery of the lesion.
- Often arise from a muscular artery.
Uncommonly present - see note:
- Necrosis (low power) - suggestive of leiomyosarcoma.
- Hypercellularity.
- Nuclear atypia seen at low power.
- Few mitoses.
Note:
- Leiomyosarcoma is diagnosed if all of the following are present: (1) high mitotic rate (dependent on site), (2) marked nuclear atypia (seen at low power), (3) necrosis.
DDx:
- Leiomyosarcoma.
- Dermatomyofibroma.[3]
- Myopericytoma / myofibroma.
Variants
- Lipoleiomyoma - with adipose tissue.
- Hypercellular leiomyoma - hypercellularity assoc. with more mutations.[4]
- Atypical leiomyoma (AKA symplastic leiomyoma) - leiomyoma with nuclear atypia.
- Benign metastasizing leiomyoma.[5]
- This is just what it sounds like. Some believe these are low grade leiomyosarcomas.
Atypical leiomyoma. (WC/Nephron)
Lipoleiomyoma - low mag. (WC/Nephron)
IHC
Work-up of suspicious leiomyomas:[6]
- CD10 +ve.
- Ki-67 -ve.
- SMA +ve.
- Desmin +ve.
Other stains:
- H-caldesmon +ve.[7]
Sign out
SKIN LESION, RIGHT LEG, EXCISION: - LEIOMYOMA. - NEGATIVE FOR MALIGNANCY. COMMENT: The lesion stains for desmin and SMA. It is negative for S-100 and has minimal staining with Ki-67.
See also
References
- ↑ URL: http://www.ncbi.nlm.nih.gov/books/NBK1252/. Accessed on: 2 September 2011.
- ↑ URL: http://ccr.cancer.gov/staff/gallery.asp?profileid=12822. Accessed on: 2 September 2011.
- ↑ Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 533. ISBN 978-0443066542.
- ↑ http://www3.interscience.wiley.com/journal/119360394/abstract
- ↑ Patton, KT.; Cheng, L.; Papavero, V.; Blum, MG.; Yeldandi, AV.; Adley, BP.; Luan, C.; Diaz, LK. et al. (Jan 2006). "Benign metastasizing leiomyoma: clonality, telomere length and clinicopathologic analysis.". Mod Pathol 19 (1): 130-40. doi:10.1038/modpathol.3800504. PMID 16357844. http://www.nature.com/modpathol/journal/v19/n1/full/3800504a.html.
- ↑ STC. 25 February 2009.
- ↑ Zámecník, M.; Kascák, P. (Jul 2011). "Uterine leiomyoma with amianthoid-like fibers.". Cesk Patol 47 (3): 125-7. PMID 21887931.