腎臟平滑肌瘤之案例報告與文獻回顧

梁柏崧、黃勝賢

彰化基督教醫院 外科部 泌尿外科

Leiomyoma of the kidney: A case report and literature review

Po-Sung Liang, Sheng-Hsien Huang

Division of Urology, Department of Surgery, Changhua Christian Hospital, Changhua, Taiwan

Introduction: Renal leiomyomas of the kidney are exceedingly rare benign tumors of the kidney originating from smooth muscle and are predominantly asymptomatic. The first case was documented by Schluter in 1890. They exhibit little aggressive activity and typically do not metastasis. The surgical prognosis for renal leiomyoma is excellent. We present a case of renal leiomyoma managed by robot-assisted retroperitoneal partial nephrectomy.

Case presentation: A 68-year-old woman reported abdominal pain for months, and the sonography showed a suspicious right renal tumor. The abdominal computed tomography (CT) revealed a bulging, lobulated mass lesion exhibiting heterogeneous enhancement in the upper pole of the right kidney. Its dimensions were approximately 4.8 x 4.2 cm. She underwent robot-assisted retroperitoneal partial nephrectomy. The pathology report indicated a leiomyoma of the kidney. The histology exhibited a distinct nodule composed of spindle cells arranged in fascicles, along with several thin blood veins within the nodule. The spindle cells showed inconspicuous nuclei and localized areas of pink cytoplasm. Immunohistochemical staining was positive for SMA, desmin and H-caldesmon but negative for cytokeratin, S-100, DOG-1, HMB-45, melan-A, CD-34, STAT-6 and PAX-8. The ki-67 proliferation index was low in the spindle tumor cells.

Conclusions: Leiomyomas of the kidney constitute roughly 0.3% of nephrectomies and 1.5% of benign renal tumors. They are primarily situated in the renal capsule (53%) and pelvis (10%). Typical manifestations include flank pain, abdominal lump and microscopic hematuria. Leiomyomas of the kidney are benign and exhibit non-aggressive behavior. The definite diagnosis of renal leiomyomas might be challenging in the pre-operative setting because to the varied imaging findings. Histological analysis facilitates the distinction of leiomyomas from other malignant neoplasms. Due to its benign nature, patients usually get positive prognoses without recurrence.