Teaching Case

A 39-year-old woman presented to our hospital complaining of abdominal distension and discomfort for the last few months. Medical history included laparoscopic myomectomy 6 years prior in another institution for the removal of a voluminous uterine fibroid, histologically confirmed. Physical examination revealed firm masses in the hypogastrium and right iliac fossa.

Contrast-enhanced CT before laparoscopic surgery was available for comparison. A large enhancing uterine mass, slightly heterogeneous, was visible, surrounded by the myometrium, consistent with an intramural leiomyoma (Figure 1). No other extrauterine abdominal lesions were seen.

Contrast-enhanced abdominal CT in our institution showed a very enlarged uterus with multiple heterogeneous contrast-enhancing solid masses of variable size. Some of them showed small hypodense areas consistent with cystic degeneration. Other solid peritoneal masses and nodules, showing similar CT characteristics, were also visible in the right iliac fossa, the left lower quadrant, and the right abdominal wall (Figure 2). The latter were in the thickness of the right rectus abdominis and oblique muscles, respectively, and related to the laparoscopic port site scars (Figures 3, 4).  

The patient underwent surgery and is under surveillance. The latest follow-up CT showed surgical changes related to bowel resections and increased size of abdominal wall lesions (Figure 5).

Disseminated peritoneal leiomyomatosis (DPL) is a rare entity characterized by proliferation of smooth muscle nodules on peritoneal surfaces of the abdomen and pelvis. Its pathophysiology is not completely known, although some authors propose that it is due to metaplasia of submesothelial multipotent mesenchymal cells, possibly influenced by hormonal factors, being more frequent in childbearing-aged women [1]. Its association with endometriosis and hysterectomy or laparoscopic myomectomy with morcellation, as in this case, has also been described [2,3]. Fragmentation of the fibroids using the morcellator may lead to peritoneal and abdominal wall seeding in the trocar sites, which may grow to form parasitic leiomyomas. This is a rare late complication of laparoscopic myomectomy [4].

It usually presents asymptomatically and hence is often diagnosed incidentally by imaging tests ordered for other reasons or during surgery. When present, symptoms are nonspecific, including abdominal distension or pain, among others.

Imaging techniques are important in preoperative diagnosis. They will show multiple nodular lesions ranging from small nodules to large solid masses of lobulated contours, well-circumscribed, without invasion of neighbouring structures. These masses may show homogeneous or heterogeneous attenuation with variable enhancement pattern similar to that of uterine leiomyomas. On MRI, they are characteristically hypointense on T2WI, which can help in the differential diagnosis with peritoneal carcinomatosis, along with the absence of suspicious ancillary features, such as lack of ascites or omental caking. Imaging tests are also useful as a guide for biopsies since definitive diagnosis is histological [5-7].

DPL is a benign condition with a tendency to spontaneous regression. The risk of malignant transformation is low, although cases of sarcomatous degeneration have been described. Due to its low incidence, there is no definite treatment consensus. A conservative approach with active surveillance is recommended unless there are symptoms or complications related to compression of abdominal structures. In these cases, therapeutic options include surgery, hormonal treatments, or chemotherapy, with little reported evidence of results [8].

Our patient underwent surgery in another institution. Histological examination of the resected lesions was consistent with leiomyomas. Since then, she has undergone two additional surgeries for recurring DLP and is currently under observation without any further treatment.

DLP with parasitic abdominal wall myomas can be seen as a rare late complication of laparoscopic myomectomy with morcellation. Radiological tests can help make an adequate diagnosis in the appropriate clinical setting. Active surveillance is necessary because recurrence is not uncommon and malignant transformation is possible.

Written informed patient consent for publication has been obtained.