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Home / Equine Research Bank / Front Vet Sci / Granulosa cell tumor in Arabian mares: prevalence, risk fact...
Frontiers in veterinary science2025; 12; 1689782; doi: 10.3389/fvets.2025.1689782

Granulosa cell tumor in Arabian mares: prevalence, risk factors, clinical and histopathological findings and outcome of surgical removal.

Abstract: Granulosa cell tumors (GCTs) represent the most common ovarian neoplasms in mares, yet data on their epidemiology, risk factors, and clinical outcomes in Arabian horses are limited. Understanding their prevalence and diagnostic features is crucial for improving fertility management in this breed. Unassigned: Clinical records from 807 Arabian mares housed on 35 stud farms in central Saudi Arabia were retrospectively reviewed to determine the prevalence of GCT and potential risk factors, including age, parity, and anabolic steroid use. Twenty-four confirmed cases were further investigated using clinical examination, ultrasonography, endocrine profiling, and histopathology. Surgical management by unilateral ovariectomy was performed in 20 mares, and postoperative fertility outcomes were documented. Unassigned: The overall prevalence of GCT was 0.6%. Logistic regression analysis identified anabolic steroid use as a significant risk factor (Odds Ratio = 13.21,  = 0.0001). Stallion-like behavior was the most frequent clinical manifestation (58.3%), followed by anestrus (33.3%) and persistent estrus (8.3%). Ultrasonography revealed four distinct tumor morphologies, with contralateral ovarian atrophy present in 75% of cases. Histopathology classified tumors into adult type (76.5%) and juvenile type (23.5%). Preoperative testosterone concentrations were elevated and decreased postoperatively in 72.7% of mares. Ovariectomy resulted in an 80% recovery rate, with 68.8% of mares regaining fertility. Unassigned: This study demonstrates that anabolic steroid administration markedly increases the risk of GCT in Arabian mares. Behavioral changes, ultrasonographic appearance, and hormonal profiles remain key diagnostic indicators, while histopathology confirms tumor classification. Surgical excision proved effective, with favorable fertility outcomes in most mares. These findings underscore the importance of early diagnosis and highlight the need for judicious use of anabolic steroids in breeding programs.
Copyright © 2025 Derar, Ali, Al-Sobayil and Refaai.
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Publication Date: 2025-11-13 PubMed ID: 41321570PubMed Central: PMC12659192DOI: 10.3389/fvets.2025.1689782Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This research investigates the prevalence, risk factors, clinical features, and outcomes of granulosa cell tumors (GCTs) in Arabian mares, focusing on their diagnosis and treatment effects on fertility.

Introduction and Context

  • Granulosa cell tumors (GCTs) are the most common ovarian tumors diagnosed in mares.
  • There is limited data specifically about GCTs in Arabian mares, which is important because breed-specific information can improve diagnosis and management.
  • This study is motivated by the need to understand how often these tumors occur, what factors contribute to their development, how they present clinically, and how they respond to treatment in Arabian horses.

Study Design and Methodology

  • Retrospective review of clinical records from 807 Arabian mares kept on 35 stud farms in central Saudi Arabia.
  • Analysis included evaluation of potential risk factors such as age, parity (number of pregnancies), and anabolic steroid use.
  • 24 mares with confirmed GCT diagnosis underwent additional detailed evaluation:
    • Clinical examination for behavioral and reproductive signs.
    • Ultrasonography to study tumor features and ovarian condition.
    • Endocrine profiling measuring hormone levels, especially testosterone.
    • Histopathological examination for tumor classification.
  • Surgical treatment involved unilateral ovariectomy (removal of one ovary) in 20 mares.
  • Fertility outcomes were monitored after surgery to assess effectiveness.

Key Findings

  • The overall prevalence of GCT in the sampled population was low at 0.6%.
  • Use of anabolic steroids was a significant risk factor, increasing the risk over 13-fold.
  • Common clinical signs included:
    • “Stallion-like” behavior in over half of the cases (58.3%), indicating hormonal influence affecting behavior.
    • Anestrus (absence of estrus cycles) in about one-third (33.3%).
    • Persistent estrus (long-lasting heat behavior) in a smaller number (8.3%).
  • Ultrasonographic examination identified four types of tumor morphologies and showed that 75% of cases had atrophy of the ovary opposite to the tumor.
  • Histopathology divided tumors into 2 categories:
    • Adult type (76.5%)
    • Juvenile type (23.5%)
  • Preoperative testosterone levels were elevated; postoperatively, testosterone decreased in nearly three-quarters (72.7%) of mares.
  • Surgical removal of the affected ovary led to an 80% recovery rate, with 68.8% regaining fertility afterward.

Implications and Conclusions

  • Anabolic steroid administration significantly increases the likelihood of developing GCT in Arabian mares, highlighting a key modifiable risk factor.
  • Clinical behavior changes like stallion-like behavior, ultrasonographic tumor features, and hormonal profiles serve as important diagnostic tools before surgery.
  • Histopathology is essential for confirming tumor type and guiding prognosis.
  • Unilateral ovariectomy is an effective treatment, with a good proportion of mares recovering fertility post-surgery, supporting surgical intervention as a beneficial management strategy.
  • Early diagnosis using clinical, imaging, and hormonal assessment is crucial for optimal outcomes.
  • The study recommends careful use of anabolic steroids in breeding programs to reduce tumor risk and preserve reproductive health.

Cite This Article

APA
Derar D, Ali A, Al-Sobayil F, Refaai W. (2025). Granulosa cell tumor in Arabian mares: prevalence, risk factors, clinical and histopathological findings and outcome of surgical removal. Front Vet Sci, 12, 1689782. https://doi.org/10.3389/fvets.2025.1689782

Publication

Frontiers in veterinary science
ISSN: 2297-1769
NlmUniqueID: 101666658
Country: Switzerland
Language: English
Volume: 12
Pages: 1689782
PII: 1689782

Researcher Affiliations

Derar, Derar
  • Department of Clinical Sciences, College of Veterinary Medicine, Qassim University, Buraydah, Saudi Arabia.
Ali, Ahmed
  • Department of Clinical Sciences, College of Veterinary Medicine, Qassim University, Buraydah, Saudi Arabia.
Al-Sobayil, Fahd
  • Department of Clinical Sciences, College of Veterinary Medicine, Qassim University, Buraydah, Saudi Arabia.
Refaai, Walid
  • Department of Surgery, Anesthesiology and Radiology, University Veterinary Hospital, Qassim University, Buraidah, Saudi Arabia.
  • Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig-City, El Sharkia, Egypt.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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