Teaching Case

A 50-year-old female was admitted for management and conduct of incidental cervical mass with suspected diagnosis of nerve sheath tumour. Surgery was performed, with histologic results of leiomyomatosis lineage. Studies before surgery were performed in another centre.

Post-surgical cervical CT confirmed a residual mass at the level of C3 to C5 and blastic lesions.

Body CT revealed the presence of small isolated lung nodules. Solid masses in the peritoneal cavity and in the abdominal wall, with heterogeneous attenuation. Many blastic lesions were seen in the vertebral bodies, ribs and pelvis, suggested of metastasis as the first diagnosis.

Spine MR showed many lesions with contrast enhancement, some of them with soft tissue component that affected the right foramen of D5 and D12.

Bone scintigraphy showed no “hot spots” suggestive of metastasis, considering the study results to be indeterminate.

A biopsy of the abdominal wall mass was performed with histological results compatible with leiomyoma, with positive estrogen and progesterone receptors.

Bone biopsy of the pelvis lesion was also performed, with histological results of focal infiltration by mesenchymal neoplasia with an immunoprotib compatible with leiomyomatous lineage.

Benign metastasic leiomyomatosis (BML), is a rare entity, characterized by proliferation of smooth muscle fibre in remote places from the uterus. Bone affection is very rare, being the lung the most frequent place of appearance. Frequently presents with a radiological appearance similar to metastasic disease. The basic pathogenesis is a multicentric metaplasic change of the mesothelial connective tissue, due to an abnormal response to ovarian hormonal simulation.

Most cases are asymptomatic and are discovered incidentally in image studies. History of hysterectomy for uterine leiomyomas can guide the diagnosis.

Ultrasound, CT and MR imaging features are useful to identify and stage the disease. It can be presented as solid and complex soft tissue masses in the peritoneum cavity, with heterogeneous enhancement. It´s not associated with infiltration of omentum, ascites or liver metástasis. The diagnosis can be confirmed by biopsy, high levels of positive estrogen and progesterone receptors can also be found.

Recurrence is possible and with each one, is more likely to produce sarcomatous degeneration, although is uncommon. Prognosis is good in postmenopausal patients, although it is variable. Cases of progression have been described and are usually related to high levels of estrogen.

Written informed patient consent for publication has been obtained.