Testis and epididymis
Spermatic cord tumors
Leiomyosarcoma (LMS)

Author: Swapnil U. Rane, M.D. (see Authors page)
Editorial Board review: Debra Zynger, M.D.

Revised: 20 July 2017, last major update March 2015

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Testis leiomyosarcoma [title]

Related topics: Soft tissue chapter

Cite this page: Leiomyosarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/testisleiomyosarcoma.html. Accessed August 18th, 2017.
Definition / general
  • Malignant mesenchymal tumor with smooth muscle differentiation
Epidemiology
Sites
Pathophysiology
  • Hypothesized to arise from cremasteric muscle, vas deferens or contractile cells of other structures such as tunica or blood vessels (Urology 2002;60:1112)
  • Paratesticular tumors belong to "deep type" of leiomyosarcoma
  • No recurrent genetic abnormality has been documented
  • Tumor spreads via lymphatic and hematogenous metastases or by local extension
  • Lymphatic spread is to regional lymph nodes: external iliac, hypogastric, common iliac, retroperitoneal (J Urol 1970;103:628)
  • Lung is most common site for hematogenous spread
Clinical features
  • Typically presents with painless, slow growing mass (at least a few months) in scrotal sac
  • Rarely presents with sudden increase in size of long standing mass
  • Aggressive tumors may invade dartos muscle and overlying skin, causing a fungating mass
Laboratory
  • Normal serum tumor markers (LDH, β-HCG, α-fetoprotein) helps exclude a germ cell tumor
Radiology description
  • Sonography shows a mass with mixed echogenicity and increased vascularity (World J Radiol 2011;3:114)
  • Color Doppler ultrasonography reveals irregular vascularity, more dominant in periphery, similar to malignant tumors
  • CT usually shows absence of fat (absence of foci with negative Hounsfield units)
  • Variable degree of hydrocele may be present
Radiology images

Images hosted on other servers:

Mass posterior superior to right testis

Huge heterogeneous enhancing mass

Heterogenous echogenicity

Prognostic factors
  • Similar to sarcoma: tumor size, tumor grade, presence of necrosis, mitotic count, completion of resection, local recurrence, distant metastases
  • Specific prognostic criteria not well established due to rarity of tumor
  • FNCLCC grading (recommended over NIH system) gives points for:
    • Differentiation: 1, well differentiated leiomyosarcoma; 2, conventional leiomyosarcoma; 3, poorly differentiated / pleomorphic / epithelioid leiomyosarcoma
    • Mitotic count: 1, 0 - 9 per 10 high powered fields; 2, 10 - 19 per 10 high powered fields; 3, 20 or more per 10 high powered fields
    • Necrosis: 0, none; 1, less than or equal to 50%; 2, greater than 50%
    • Grade 1 is 2 - 3 points, grade 2 is 4 - 5 points and grade 3 is 6 - 8 points
Case reports
Treatment
  • Radical orchidectomy for resectable tumors
  • Simple excision is insufficient as residual disease was found in 27% of cases that underwent repeat wide excision (J Urol 1981;126:611)
  • Uncertain role of adjuvant radiation or chemotherapy; some authors recommend adjuvant therapy in high grade / high risk tumors and others recommend adjuvant radiotherapy for all grades to reduce local recurrence (Cancer 1996;77:1873, J Urol 1991;146:342)
  • Prophylactic retroperitoneal lymph node dissection may be performed but no survival benefit has been documented, so dissection recommended only if nodes are suspicious for involvement (J Urol 1970;103:628)
  • Single or multiagent chemotherapy with anthracyclines and if osfamides or gemcitabine for nonoperable or metastatic tumors
Clinical images

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Ulcerated and fungating tumor involving scrotum

Gross description
  • Tumor typically located outside tunica albuginea, may be centered on epididymis or spermatic cord
  • Cut surface is usually firm, gray white
  • Grossly identifiable necrotic and hemorrhagic areas may be seen
Gross images

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Well defined huge solid mass

Paratesticular

Microscopic (histologic) description
  • Interlacing fascicles of spindle shaped cells with eosinophilic cytoplasm and cigar shaped nuclei
  • Mitotic activity is usually seen; necrosis may be seen
  • At least mild atypia; more undifferentiated cases have marked cellular atypia
  • Variably scattered mast cells, inflammatory cells, hyalinization
  • Histological variants:
    • Epithelioid
    • Dedifferentiated / pleomorphic
      • Discrete transition to more pleomorphic tumor (reminiscent of malignant fibrous histiocytoma) without any smooth muscle differentiation
      • Dedifferentiated areas are usually negative for all myogenic markers
      • Heterologous osseous or chondro-osseous elements may be seen rarely
    • With osteoclast-like giant cells (Urol Int 1996;56:259)
    • Myxoid (Am J Surg Pathol 2000;24:927)
    • Inflammatory
Microscopic (histologic) images

Images hosted on PathOut server:

Case of Week #254




Images hosted on other servers:

Mild cytologic atypia

Multipolar mitotic figures

Pattern of spindle cells - H&E


Mitotic activity and atypical nuclei


Desmin+, SMA+

Desmin+

SMA+

Immunohistochemistry
Electron microscopy description
Differential diagnosis