Imaging of leiomyosarcoma of the uterus

Clinical History

History of left flank pain from time to time and 4-month history of a pelvic mass and low abdominal pain. On pelvic examination, a large ill-defined, globular, non-tender uterus was palpated. There was a positive left Giordano sign.

Imaging Findings

The patient presented with a 4-month history of a pelvic mass and low abdominal pain. On pelvic examination, a large ill-defined, globular, non-tender uterus was palpated. The rest of clinical examination revealed a positive left Giordano sign (pain or sensitivity initiated after palpation or mild hit of the lumbar region with the inner side of the examiner's palm - especially in cases of nephrolethiasis). The patient had a medical history of left flank pain from time to time, along with calyceal dilatation. On admission abdominal ultrasonography was performed, which showed moderate pyelocaliceal dilatation including the upper one third of the ureter of the left kidney, as well as a large mass with solid and cystic components extending from the enlarged uterus to the mid-abdominal level. An IVP showed no evidence of excretion of the left kidney even when delayed films were obtained (24 hours after contrast injection). Under suspicion that the mass may have spread beyond the uterus, to the rest retroperitoneal space, encasing the left ureter, a retrograde pyelogram was performed, to depict the lower two thirds only. An abdominal CT before and after contrast administration completed the imaging studies. A huge (10cm x 13cm) diffuse inhomogeneous mass was demonstrated, originating from the uterus and extending to the retroperitoneum. After enhancement, hypodense areas which indicated some degenaration, were noted within the tumour. The preoperative serum CA-125 level was 248IU/ml and other laboratory values were normal. A total hysterectomy and bilateral salpingoophorectomy were performed. Pathological examination of the excised mass confirmed the diagnosis of a uterine leiomyosarcoma. The left ureter was found compressed at it's lower third by the presence of the mass. 18 months postoperatively, 2 months after completion of the sixth chemotheraphy cycle, the patient returned with hypertention and pelvic pain, most probably due to local reccurence.

Discussion

Uterine leiomyosarcomas (LMS) are rare female neoplasms that account for about 1% of all uterine malignancies and for approximately 25% of uterine sarcomas. Uterine LMS are considered neoplasms of high malignant potential with 5-year overall survival rates varying between 0% and 73%. They most frequently present in women around the age of 40. According to recent definitions, uterine smooth muscle tumours with 5 or more mitoses per 10 high power fields and nuclear atypia are defined as LMS. Most of them are considered to be idiopathic. Most leiomyosarcomas extend silently within the retroperitoneum or mesentery and achieve a large size by the time of diagnosis. Metastases tend to be haematogenous, with the liver, lung and peritoneal surfaces being common sites. Lymphatic spread and bone metastases are less common but can occur.

Computed tomography (CT) is very useful for evaluating the primary characteristics and secondary patterns of spread of such a neoplasm. It can show the extent of the primary tumour, identify metastases, and localise lesions for biopsy. The CT appearance of LMS is not specific.

The differential diagnosis of LMS includes other neoplasms such as leiomyoma, lymphoma, or other types of sarcoma and mucinous cystic neoplasm. Nevertheless a group of findings that occur rather frequently among patients may suggest consideration of this diagnosis. These include large masses with central necrosis or liquefaction and frequent liver metastases that also are often necrotic or cystic in appearance. The associated presence of pulmonary, mesenteric, omental, nodal, or soft tissue metastases, especially if necrotic, should suggest the diagnosis of LMS. Calcification is not usually observed in any of the tumour masses or metastases. Intravenous pyelogram, abdominal ultrasound, colonoscopy, double contrast barium enema and cysteoscopy, lemphangiography and MRI may also contribute to the diagnosis.

Differential Diagnosis List

Final Diagnosis

Leiomyosarcoma of the uterus

URL:	https://www.eurorad.org/case/1780
DOI:	10.1594/EURORAD/CASE.1780
ISSN:	1563-4086