Breast malignant, males, children
Sarcoma
Leiomyosarcoma

Author: Emily S. Reisenbichler, M.D. (see Authors page)

Revised: 27 July 2016, last major update July 2016

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

PubMed Search: Leiomyosarcoma [title] breast

Cite this page: Leiomyosarcoma. PathologyOutlines.com website. http://pathologyoutlines.com/topic/breastmalignantLMS.html. Accessed December 9th, 2016.
Definition / General
  • Malignant smooth muscle neoplasm of the breast
Essential Features
  • Rare, < 1% of all breast malignancies
  • Less than 50 primary leiomyosarcomas of the breast reported in the literature
  • Should be distinguished from metastatic tumor
Etiology
  • Primary tumors likely arise from smooth muscle of the nipple or vascular wall
  • Have been reported to occur secondary to radiation (Surg Case Rep 2015;1:76)
Clinical Features
Radiology Description
  • Mammographically presents as a mass or architectural distortion
  • By ultrasound, lesions are homogenously hypoechoic, lobular or oval with microlobulated or indistinct margins (Acta Radiol 2011;52:597)
Prognostic Factors
  • Type of surgery does not affect prognosis as long as the tumor is excised with an adequate (2 - 3 cm) margin (Breast 2011;20:389)
  • Due to the rare nature of this tumor, no specific prognostic features are established in primary leiomyosarcoma arising in the breast
  • If the tumor is cutaneous and limited to the dermis of the breast skin (i.e. atypical intradermal smooth muscle neoplasm), rather than arising in the mammary parenchyma, prognosis is excellent without metastases
Case Reports
Treatment
  • As no axillary lymph node metastases have been reported with primary breast leiomyosarcoma, sentinel lymph node excision is not indicated (Breast 2011;20:389)
  • Wide excision with at least 2 cm margin, but 3 cm margin is recommended (Breast 2011;20:389)
  • In tumors larger than 3 cm, or with inadequate excision, radiotherapy may be indicated
  • Adjuvant chemotherapy may result in greater clinical response in radiation induced sarcomas (Surg Case Rep 2015;1:76)
Gross Images

Images hosted on other servers:

Lobulated elastic tumor

Micro Description
  • Intersecting fascicle of spindled cells with abundant eosinophilic cytoplasm and cigar shaped nuclei demonstrating variable pleomorphism, mitotic activity and necrosis
  • Tumor borders are typically infiltrative
Micro Images

Images hosted on PathOut servers:

Interesecting fascicles, pleomorphic nuclei and mitotic activity, courtesy of Emily S. Reisenbichler, M.D.

Nuclear pleomorphism and mitotic activity (AFIP)

Dense cellularity and intersecting fascicles



Dermis involvement, courtesy of Mark R. Wick, M.D.

Parenchyma, courtesy of Mark R. Wick, M.D.

Desmin, courtesy of Mark R. Wick, M.D.



Images hosted on other servers:

Cellular pleomorphic tumor

Nipple areola complex

Densely cellular tumor

Cigar shaped nuclei

SMA+

Alpha smooth muscle actin

Cytology Description
  • Large, dissociated round to spindle cells, medium to large, with abundant vacuolated cytoplasm with occasional intranuclear cytoplasmic invaginations
  • Mitotic activity, including abnormal forms, nuclear atypia and a necrotic background favor a malignant process
  • Immunohistochemistry is typically required to distinguish leiomyosarcoma from other malignant spindle cell tumors of the breast (Diagn Pathol 2006;1:13)
Cytology Images

Images hosted on other servers:

Various images

Positive Stains
Negative Stains
Molecular / Cytogenetics Description
Differential Diagnosis