A Case Report of Leiomyosarcoma of The Ureter in a Sudanese Woman One Year Follow up

Leiomyosarcoma is a malignant tumor of smooth muscle origin and accounts for fewer than 1% of all urinary tract tumors. Although these tumors can arise in various anatomical locations, their occurrence in the ureter is particularly rare. This case report describes the clinical presentation, diagnostic evaluation, surgical management, and follow-up of a woman diagnosed with leiomyosarcoma of the ureter. Leiomyosarcoma can be classified based on histological features into various subtypes, including pleomorphic, spindle cell, and myxoid variants. Recent studies have highlighted the importance of immunohistochemical staining in differentiating leiomyosarcomas from other smooth muscle tumors such as leiomyomas and other sarcomas [1]. Patients with ureteral leiomyosarcoma typically present with nonspecific symptoms, which may include flank pain, hematuria, and urinary obstruction. Due to the nonspecific nature of these symptoms, the diagnosis can often be delayed [2]. Advanced imaging techniques, including CT scans and MRI, are essential in identifying ureteral masses and assessing local invasion [3].

The definitive diagnosis of ureteral leiomyosarcoma is established through histopathological examination of a biopsy or excised tissue. Recent advancements in molecular pathology have provided further insights into the genetic alterations associated with leiomyosarcoma, aiding in diagnosis and potentially guiding targeted therapies [4]. The primary treatment for ureteral leiomyosarcoma involves surgical resection, which may include nephroureterectomy depending on the tumor’s extent. Recent literature indicates that complete resection is associated with improved outcomes, although the prognosis remains poor for advanced-stage disease [5]. Adjuvant therapies, including chemotherapy and radiation, have been explored, but their efficacy varies [6]. The prognosis for patients with leiomyosarcoma of the ureter tends to be poor due to late presentation and high rates of metastasis. Recent studies have reported five-year survival rates significantly correlated with tumor stage at diagnosis, with localized disease showing more favorable outcomes compared to metastatic forms [7].

A 47-year-old Sudanese woman presented with a complaint of left loin pain, which she reported had persistently worsened over the past year but had become particularly severe in the last month. Notably, the pain was continuous, moderate in intensity, and was not associated with any episodes of hematuria. Her medical history was unremarkable, and she had not experienced any weight loss, fever, or other systemic symptoms, or displayed lower urinary tract symptoms nor any signs of hematuria. Upon examination, the patient appeared unwell, although she did not exhibit pallor, and there were no detectable palpable masses. Physical examination revealed no abdominal tenderness and the patient was hemodynamically stable. Investigations revealed the following laboratory results: hemoglobin at 12.2 g/dL, total white blood cell count at 5.5 x 10^3/ μL, platelets at 454 x 10^3/μL, serum creatinine at 0.8 mg/dL, urea at 27 mg/dL, potassium at 3.2 mmol/L, and sodium at 138 mg/dL. A urine analysis yielded normal results.

An abdominal ultrasound identified a mass located just below the left kidney. Subsequent contrast-enhanced CT imaging of the abdomen confirmed the presence of a retroperitoneal mass situated adjacent to the left kidney but not adhered to it, positioned left of the aorta and measuring [30×30×25 mm]. A CT-guided biopsy was performed on the mass, which subsequently revealed a diagnosis of leiomyosarcoma of unknown origin. Given the imaging findings and the patient’s considerable symptoms due to urinary obstruction, surgical intervention was planned. The patient was consented to various probabilities of surgery and on March 11, 2023, the patient underwent surgical intervention. During the procedure, it was observed that the left ureter traversed the mass, which was found to be inseparable from the renal pedicle. Consequently, the left kidney was excised along with the mass. The patient experienced a smooth intraoperative and postoperative course, and histopathological examination confirmed the diagnosis of leiomyosarcoma arising from the ureter. Immunohistochemical analyses were also conducted, and the initial diagnosis was corroborated.

The resected specimen was sent for histopathological evaluation. Microscopic examination revealed spindle-shaped cells with atypical nuclei and a high mitotic index, consistent with a diagnosis of leiomyosarcoma. Immunohistochemical studies confirmed the smooth muscle origin of the tumor (Figures 1-4).

The postoperative course was uneventful, and the patient was discharged home after a few days of observation. A followup regimen was established which included clinical evaluations, imaging studies, and laboratory tests over the course of one year. Notably, the patient has remained asymptomatic with no clinical or radiographic evidence of tumor recurrence during this period.

This case exemplifies the diagnostic challenges faced in identifying rare tumors such as leiomyosarcoma of the ureter. Patients often present with obstructive uropathy, leading to delays in diagnosis if malignancy is not considered in the differential. The rarity of ureteral leiomyosarcoma necessitates awareness among clinicians for timely diagnosis and appropriate treatment. Urothelial malignancies account for a substantial proportion of urinary tract cancers; however, primary sarcomas arising from the ureter are exceedingly rare. In this case report, we discuss a 47-year-old Sudanese woman diagnosed with leiomyosarcoma of the ureter, a condition that underscores the necessity for awareness regarding this uncommon malignancy among clinicians. The presenting symptom in these studies including ours was pain in the abdomen and flank, while in a study by Shastri [8], it was a lump in the abdomen. Hematuria was also seen to be a chief complaint in a few cases [9].

The cause of this tumor is still not clear due to limited data, although some available data suspect retinoblastoma 1 gene mutation, previous pelvic radiotherapy, and the use of cyclophosphamide to be causative [10]. The patient presented with a one-year history of loin pain but notably did not exhibit any signs of hematuria, which is often a key symptom in urinary tract malignancies. This absence of hematuria may have contributed to a delayed diagnosis, as such symptoms typically prompt further investigation. It is crucial that healthcare providers maintain a high index of suspicion when faced with unexplained pain in the renal region, particularly in patients with unusual presentations or risk factors, to consider a broader differential diagnosis, including rare tumors like leiomyosarcoma. Computed tomography (CT) urography played a vital role in the diagnostic process, revealing a mass encasing the left ureter, which led to hydronephrosis.

The visualization of hydronephrosis, indicative of obstructive uropathy, highlights the critical nature of prompt imaging in patients presenting with non-specific symptoms. CT imaging is invaluable not only for confirming the presence of a mass but also for assessing its extent and potential involvement with surrounding structures. Intraoperatively, the extent of the mass was found to be extensive, involving the ureter and extending to its upper portion. Surgical intervention remains the cornerstone of treatment for localized sarcomas, particularly in cases where the lesion is respectable. The decision for surgical management needs to carefully evaluate the tumor’s involvement with adjacent structures, as well as the potential for complete resection to achieve negative margins—an essential component for reducing the likelihood of recurrence. Histopathological examination confirmed the diagnosis of leiomyosarcoma, providing critical information for guiding further management and follow-up. Leiomyosarcoma is characterized by malignant smooth muscle cells and can be associated with relatively aggressive behavior and Leiomyosarcoma shows nodular aggregates and densely packed, interlacing bundles of smooth muscle cells in the center.

At the margin, strands of smooth muscle cells extend between collagen bundles. Areas of lesser differentiation are present in all tumors to varying degrees, including irregularly shaped, anaplastic nuclei, and atypical giant cells with bizarre nuclei. A high mitotic rate remains the main criterion for leiomyosarcoma. The prognosis depends significantly on factors such as tumor size, grade, and the extent of local invasion. Postoperatively, this patient was followed for one year without evidence of tumor recurrence, suggesting that complete surgical resection may lead to favorable outcomes in selected patients with localized leiomyosarcoma of the ureter. This finding aligns with existing literature indicating that early diagnosis and complete surgical excision are associated with improved prognosis in soft tissue sarcomas. Leiomyosarcoma of the ureter is a challenging malignancy characterized by its rarity and aggressive behavior. Ongoing research is essential to elucidate the underlying mechanisms, improve diagnostic accuracy, and develop effective treatment regimens.

Collaborative efforts among pathologists, oncologists, and urologists are crucial to optimize patient care and improve outcomes for individuals affected by this condition. The management of this condition involves complete surgical resection, which is essential for both symptom relief and potential cure. The absence of recurrence in our patient over one-year post-surgery is encouraging and suggests that early intervention may improve outcomes. The patient has been followed for a complete year with no related complaints and the CT urography was normal as yet the best imaging to establish recurrence is a PET scan. Ureteric leiomyosarcoma is rare with just 20 cases reported to date [11,12]. The etiology, diagnostic modalities, and treatment are still a topic of debate as the available literature is scarce.

Leiomyosarcoma of the ureter is a rare malignancy that requires a high index of suspicion for diagnosis. Comprehensive imaging studies and surgical intervention are critical for effective management. Continued follow-up is essential to monitor for recurrence, although our patient has not demonstrated any signs of recurrent disease after one year. This case contributes to the limited literature on ureteral leiomyosarcoma and emphasizes the need for further studies to enhance the understanding and management of such rare tumors. It also emphasizes the importance of considering rare diagnoses such as leiomyosarcoma in patients with unexplained loin pain, even in the absence of hematuria. It reinforces the utility of imaging modalities like CT for diagnosis and highlights the significance of surgical intervention in providing favorable outcomes. Ongoing follow-up is essential to monitor for potential recurrence, given the aggressive nature of such tumors. Further studies investigating the long-term outcomes and optimal management strategies for leiomyosarcoma of the ureter are warranted to improve patient care and outcomes in this rare but challenging condition.

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