Leiomyomatosis peritonealis disseminata (LPD)/parasitic leiomyoma (PL) is a rare variant of smooth muscle nodules occurring outside the uterus. According to FIGO classification, parasitic leiomyoma is of type 8, Kelly and Cuccess in 1909 first described parasitic leiomyoma. Extra uterine leiomyomas are rare, present with unusual growth pattern or occur in an unusual location that make their identification more challenging both clinically and radiologically. The clinical presentation is nonspecific and depends on the site of recurrence. Most of these patients are asymptomatic and if symptomatic abdominal swelling/pelvic mass, pressure or abdominal distension, are the manifestations. A fibroid away from the uterus with a history of laparoscopic myomectomy/hysterectomy with power morcellation gives a clue of LPD/parasitic leiomyoma.
Surgical excision is the main treatment.
A 28-year-old nulligravida consulted us with a complaint of mass in the upper abdomen, noticed 5 months ago. She underwent laparoscopic myomectomy and power morcellation for a very large fibroid (unknown dimensions) seven years ago in 2015. Examination revealed a swelling beneath the supra umbilical trocar site. Subsequent ultrasound and magnetic resonance imaging (MRI) done during evaluation by us during February 2022 demonstrated multiple tumors of varied sizes all over the abdomen that included the port site (Fig. 1).
Multiple lobulated well-defined space occupying lesions that varied in size with MR signal pattern of myomata (T2 hypointense, T1 Isointense, DWI low signal) were noted in the abdominal cavity in different locations (intraperitoneal, anterior abdominal wall and portside entry) attached to the mesentery, peritoneum and anterior abdominal wall with characteristics features of parasitic leiomyomata, mapped in the pelvic cavity, 43 mm largest diameter on the right side, 31 mm, 21 mm and, 66 mm on the right peritoneal, anterior abdominal wall with cystic degeneration spread over the transverse abdominal muscle (9.4 cm). Portside entry at umbilicus 49 × 66 mm, 55 mm at the mesenteric attachment in supramesocolic compartment, 49 mm in left paracolic gutter, 21 mm along right round ligament was noted. Vascularity from the peritoneum (Table 1).
Majority of the myomata were predominantly T2 dark/ diffussion weighted imaging (DWI) dark/apparent diffusion coefficient (ADC) low (between 0.9–1.1) consistent with benign morphology: T2 dark DWI one myoma in right anterior abdominal wall showed central T2 hyperintensity DWI bright with ADC value of 1.6–1.9 suggesting T2 shine through and cystic degeneration.
Therapeutic intervention: an operative laparoscopy was performed under general anesthesia GA. Multiple white gray nodules of varying sizes at different locations were noted. Twenty-one nodules were excised. All the tumors removed intact through a small minilap suprapubic incision, thus avoiding morcellation. Histopathological examination of the tissue was consistent with fibroids (Fig. 2).
Of the 21 fibroids, the largest was 11.9 cm, anterior abdominal wall fibroid showed cystic degeneration splaying the transverse abdominal muscle. Most of the fibroids derived the vascularity either from the peritoneum/mesentry/ omentum.
There were no uterine leiomyomas and the previous myomectomy scar was intact. Blood loss was very minimum intraoperatively. Post-operative recovery was uneventful. Multiple fibroids varied in size from 0.6 × 0.4 to 11.6 × 11.9 cm, serial sections across all the fibroids were solid grey white and grey brown and whorled with focal myxoid areas macroscopically. Microscopic examination revealed leiomyomas with fascicles of smooth muscle cells with oval nuclei and fine chromatin (Fig. 2). Intervening hypocellular foci was noted. There was no evidence of malignancy.
LPD is a rare late sequel of uterine leiomyomas, first described in 1952 by Wilson and Paele. It can affect women in their reproductive age, premenopausal and sometimes in postmenopausal women. The etiology and pathophysiology of LPD can be either primary or iatrogenic, the latter being more common due to uncontained power morcellation of fibroids, which augments the potentiality of tumor implantation and dissemination.
LPD originates from metaplasia of submesothelial, multipotential mesenchymal cells and associated with exposure to high endogenous or exogenous estrogens, as in prolonged usage of contraceptive pills and pregnancy. In LPD, tumor cells have both estrogen and progesterone receptors. In addition, autosomal dominant model with varying level of penetrance has been reported in the literature, explaining the occurrance of familial clustering.
Due to uncontained laparosocopic myomectomy/hysterectomy procedures the LPD/Parasitic leiomyoma cases are increasing. Kimberly and his colleagues reported 12 cases of parasitic fibroids with a history of previous morcellation procedure. Lu et al. presented 6 cases of such tumors. All of them had history of myomectomy/hysterectomy with power morcellation.
A retrospective study over 3 years by Gaspare and associates showed the development of PL after power morcellation. Of 425 cases, 0.9% developed PL. It was concluded that uncontained morcellation is a risk factor for developing LPD/PL. Thus came In-bag morcellation of the fibroids to minimise spillage. Table 2 describes the case reports of LPD reported by various authors excluding the 37 cases listed by Huang et al. A careful inspection and thorough washing of the abdomen and pelvic cavities should be done after the procedure.
Majority (93%) of PL occur in pelvis. Many authors reported LPD/PL but rarity in our case is having a leiomyomas in the abdomen and pelvic areas along with the port site and on the large intestine. Dashraath et al. reported the mass on greater omentum. Concomitant occurrence of uterine leiomyomas and LPD have been reported. In our case, uterus, both fallopian tubes, and ovaries were absolutely normal with an intact previous myomectomy scar.
Intracapsular myomectomy, the removal of fibroids from its pseudocapsule, may prove a promising surgical technique, not only for uterine myometrial healing but also in preventing LPD. A pseudo-capsule is defined as an anatomic structure surrounding the fibroid and separating it from the normal myometrium, which has a high angiogenic potential derived from growth factor iatrogenic damage and spread of pseudo capsule by power morcellation could promote implantation of minced leiomyoma fragments at an ectopic site.
Management is generally resection and excision, which can be by open, laparoscopic or robotic procedure. In this case, to avoid morcellation and further recurrence, a small suprapubic incision was given, and all the fibroids were removed intact.
Conflict of Interest Nil.
Ethical Approval Not required for reporting individual cases.
Human or Animal Consent Nil.
Informed Consent Written informed consent obtained from the patient.
