Home   Chapter Home   Jobs   Conferences   Fellowships   Books


Lung tumor

Benign tumors

Benign metastasizing leiomyoma

Reviewer: Deepali Jain, M.D. (see Reviewers page)
Revised: 6 January 2013, last major update September 2012
Copyright: (c) 2003-2013, PathologyOutlines.com, Inc.


● Benign appearing leiomyoma in lung, clonally derived from benign-appearing uterine leiomyomas (Mod Pathol 2006;19:130)
● Rare, ~100 cases reported to date
● Usually women ages 36-64 years, mean 44 years, often with prior history of uterine leiomyomas
● Regress during pregnancy or after oophorectomy
● May represent a well differentiated leiomyosarcoma of low malignant potential, metastatic to lung
● Nodule on chest Xray, but usually only mild cough and shortness of breath or no symptoms
● Good prognosis

Case reports

● 48 year old woman with incidental retroperitoneal mass and multiple lung nodules (Clin Exp Reprod Med 2011;38:174)
● 76 year old woman with bilateral pulmonary nodules (Arch Pathol Lab Med 2003;127:501)
● Presenting as cystic lung disease (Histopathology 2011;59:786)


● Hysterectomy, bilateral salpino-oophorectomy, long term hormonal therapy

Gross images

Retroperitoneal and lung masses

Micro description

● Well circumscribed, single or multiple nodules of smooth muscle, composed of elongated cells with abundant eosinophilic cytoplasm, oval nuclei, inconspicuous nucleoli
● Large, irregularly shaped thick walled vessels
● May contain cysts
● No atypia, no vascular invasion, no mitotic figures

Micro images

Various images

Comparison with leiomyosarcoma

Cytogenetics description

● Genetically distinct entity with consistent chromosomal aberrations (19q and 22q terminal deletion in all cases, Am J Surg Pathol 2007;31:737)

Differential diagnosis

Low grade leiomyosarcoma: miR-221 expression differentiates leiomyosarcoma from benign metastasizing leiomyoma, Diagn Mol Pathol 2008;17:145)

End of Lung tumor > Benign tumors > Benign metastasizing leiomyoma

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).