A Rare Case of Recurrent Vulvovaginal Smooth Muscle Tumor with Uncertain Malignant Potential (STUMP)

Introduction Smooth muscle tumors, while common in areas such as the uterus, are rare in the vulva and vagina. Among these, Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP) represents a unique category with diagnostic and clinical management challenges. This blog post outlines a notable case involving recurrent vulvovaginal STUMP, highlighting the clinical presentation, diagnostic approach, treatment, and follow-up strategies.

Case Overview A 42-year-old female presented with a recurrent, painless mass in the vaginal region that had been increasing in size over three months. She had a prior history of excision surgeries for similar masses, diagnosed initially as leiomyoma and later as STUMP. The current clinical examination revealed a 6–7 cm firm, mobile, non-tender mass originating from the anterior vaginal wall, along with another 4 cm mass in the left labium majus. Imaging studies suggested recurrence, and surgical excision was planned.

Diagnosis and Surgical Intervention MRI scans confirmed the presence of well-defined lesions, prompting surgical removal. The tumors were dissected, and careful measures were taken to preserve surrounding structures and ensure complete excision. Histopathological analysis revealed spindle-shaped cell fascicles with mild nuclear atypia and low mitotic activity, consistent with STUMP. Immunohistochemistry showed positivity for markers such as Vimentin, Desmin, and SMA, confirming the smooth muscle origin.

Discussion STUMP cases are complex due to their unpredictable clinical behavior. They can exhibit features between benign leiomyomas and malignant leiomyosarcomas, making long-term monitoring essential. This case, along with literature reviews, highlights the rarity and recurrence potential of such tumors, underscoring the importance of thorough follow-up.

Clinical Implications and Recommendations Due to the uncertain malignant potential, managing STUMP involves:

• Surgical Excision: Complete removal of the tumor with clear margins.
• Histopathological and Immunohistochemical Analysis: Essential for accurate diagnosis and differentiation from more aggressive neoplasms.
• Long-term Monitoring: Regular follow-ups, initially every six months and then annually, to detect potential recurrence or progression.

Conclusion STUMP of the vulvovaginal region remains an infrequent and diagnostically challenging condition. Cases like this underscore the importance of a multidisciplinary approach in managing rare tumors, emphasizing surgical precision and vigilant follow-up.

Tags: Vulvovaginal Tumors, Smooth Muscle Tumor, STUMP, Gynecology Oncology, Recurrent Tumors, Surgical Oncology, Case Study