Disseminated peritoneal leiomyomatosis incidentally diagnosed during surgery for torsion of a subserosal uterine fibroid: a case report

Abstract

Background

Disseminated peritoneal leiomyomatosis is a rare condition characterized by the dissemination of histologically benign leiomyomas within the peritoneal and retroperitoneal cavities. Intra-abdominal findings can resemble the peritoneal dissemination of gynecologic or gastrointestinal malignancies. Disseminated peritoneal leiomyomatosis has been predominantly reported in patients with a history of gynecological treatment or during pregnancy. Herein, we present a case of disseminated peritoneal leiomyomatosis diagnosed incidentally following the torsion of a uterine fibroid in a patient without prior gynecological treatment. This presentation is extremely rare, particularly because it occurred in a postmenopausal woman and manifested as an acute abdomen without any prior gynecologic intervention.

Case presentation

A 53-year-old Japanese woman (gravida 2, para 2) was under observation for multiple uterine fibroids without treatment. The patient was postmenopausal and had no significant medical, surgical, family, or psychosocial history, and no history of hormonal therapy or other gynecologic interventions. The patient presented with sudden-onset lower abdominal pain and was emergently transported to our hospital with a suspected diagnosis of torsion of an ovarian tumor or pedunculated subserosal uterine fibroid. Emergency laparotomy revealed a 15 cm pedunculated subserosal fibroid with 180° of torsion. In addition to the multiple uterine fibroids, multiple nodules were observed in the omentum and pelvic peritoneum. Therefore, a total abdominal hysterectomy, bilateral salpingo-oophorectomy, partial omentectomy, and pelvic peritonectomy were performed. Histopathological examination revealed multiple uterine, omental, and peritoneal leiomyomas, leading to the diagnosis of disseminated peritoneal leiomyomatosis. Postoperative computed tomography demonstrated small residual nodules on the pelvic floor that were also suspected to be leiomyomas. The patient remains under continuous follow-up, with no evidence of disease progression over more than 3 years of postoperative surveillance. Although the patient presented with fever, tachycardia, and elevated inflammatory markers, no infectious workup such as blood cultures was performed because the clinical presentation and computed tomography findings strongly supported torsion as the primary etiology; however, infectious evaluation should also have been considered.

Conclusion

When unexpected intraoperative peritoneal dissemination is encountered, disseminated peritoneal leiomyomatosis should be considered in the differential diagnosis alongside malignancy, recognizing that it can develop even in a patient without prior gynecologic treatment, which is extremely rare. Careful intra-abdominal assessment and appropriate surgical decision-making are essential. Given that only isolated reports have described disseminated peritoneal leiomyomatosis presenting with acute abdomen or torsion-related symptoms, the present case further underscores the exceptional rarity of this clinical scenario.

Background

Disseminated peritoneal leiomyomatosis (DPL) is a rare disease characterized by the peritoneal and retroperitoneal dissemination of smooth muscle tumors without malignant histological features [1]. This disease is frequently reported in patients with a history of gynecological procedures such as myomectomy or during pregnancy [2, 3]. In cases of peritoneal dissemination, DPL must be differentiated from malignant gynecological or gastrointestinal tumors, and the imaging diagnosis remains challenging [4]. Herein, we report a case of DPL incidentally diagnosed during surgery for subserosal uterine fibroid torsion in a patient without a history of gynecological treatment. Although DPL has occasionally been reported to present with acute abdomen or torsion-related symptoms, such cases are extremely rare and limited to isolated reports such as acute abdomen [5] or omental torsion [6], underscoring the clinical rarity of the present case.

Case presentation

A 53-year-old Japanese woman, gravida 2, para 2, who experienced menopause at 51 years of age, presented with a history of multiple uterine fibroids diagnosed more than 10 years ago. The patient was under observation at a local clinic and had no history of myomectomy. The patient also had no significant medical, surgical, family, or psychosocial history relevant to the present condition, and no history of hormonal therapy or other gynecologic interventions. The patient had developed persistent lower abdominal pain a few days before presentation. A pelvic mass was identified, raising the suspicion of torsion of an ovarian tumor or a subserosal uterine fibroid. The patient was then urgently referred to our hospital for further evaluation and management.

Upon admission, the patient’s vital signs were as follows: temperature 38.2 °C, heart rate 107 beats per minuute, and blood pressure 167/104 mmHg. Gynecological examination revealed no significant findings on colposcopy; however, a bimanual examination revealed a firm, elastic mass at the level of the umbilicus, which was tender to palpation. Abdominal ultrasonography confirmed the presence of the mass at this location, whereas transvaginal ultrasonography revealed multiple uterine fibroids without endometrial thickening or adnexal enlargement. Laboratory results showed an elevated white blood cell count (19,200/μL) and C-reactive protein level (21 mg/dL) with a normal lactate dehydrogenase level (250 U/L). Although the patient demonstrated fever, tachycardia, and elevated inflammatory markers, no infectious workup including blood cultures was performed because the clinical presentation and computed tomography (CT) findings were strongly suggestive of torsion.

Abdominal contrast-enhanced computed tomography (CT) revealed multiple uterine fibroids, moderate ascites, and a subserosal uterine fibroid in the fundus with poor contrast enhancement (Fig. 1). Based on these findings, torsion of the uterine fibroid resulting in acute abdomen was suspected, and an emergency laparotomy was performed.

Fig. 1.

Abdominal computed tomography images. A Coronal section showing a large uterine fibroid with moderate amount of ascites (arrow). B Horizontal section in which the subserosal fibroid of the uterine fundus shows poor contrast, and torsion of the fibroid is suspected (arrow). Asterisk indicates the uterine body with contrast effect

Intraoperatively, a 15 cm subserosal uterine fibroid was twisted 180° (Fig. 2A). Additional fibroids with the potential for torsion were also identified. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed (Fig. 3A, B). Multiple nodules were observed in the omentum (Fig. 2B) and pelvic peritoneum, necessitating omental resection (Fig. 3C) and excision of as many disseminated lesions as possible. Histopathological examination revealed congestive changes in the twisted fibroid, with no malignant findings in the uterus, adnexa, or disseminated lesions in the omentum or pelvic peritoneum, all of which were consistent with benign smooth muscle tumors (Fig. 4). Based on these findings, the diagnosis of DPL was made.

Fig. 2.

Intraoperative findings. A A dark red subserosal uterine fibroid is seen in the fundus of the uterus. The arrow indicates the site of torsion, and asterisk shows normal uterine body. B In the greater omentum, multiple yellow to milky white nodular lesions are found

Fig. 3.

Macroscopic findings. A Uterus and bilateral adnexae. Multiple uterine fibroids are found, whereas the bilateral adnexae have no abnormal findings. B: twisted subserosal uterine fibroid with congestion. C Multiple yellow to milky white nodular lesions in the greater omentum

Fig. 4.

Microscopic findings. A Hematoxylin and eosin staining of the twisted uterine fibroid with smooth muscle cells arranged in a cord-like manner without cellular atypia or mitotic figures. There is congestion throughout the tissue. Magnification: × 200. B Hematoxylin and eosin staining of the nodular lesions in the greater omentum with smooth muscle cells arranged in a cord-like manner without cellular atypia or mitotic figures. Neither necrosis nor infiltrative proliferation is observed. Magnification: × 400. C Tumor cells in the greater omentum are positive for alpha-smooth muscle actin (α-SMA). Magnification: × 400.

The postoperative course was uneventful, and the patient was discharged on postoperative day nine. Contrast-enhanced abdominal CT performed 1 month after surgery showed suspected residual smooth muscle tumors on the pelvic floor, and the patient continues to be monitored. No signs of disease progression have been observed at 3 years and 7 months postoperatively. Follow-up has consisted of clinical evaluation and imaging at intervals of 6–12 months, with annual CT scans to monitor stability of residual nodules; ongoing follow-up decisions are individualized on the basis of symptoms, menopausal status, and imaging stability.

Discussion

In the present case, DPL was diagnosed incidentally during the torsion of a uterine fibroid. Diagnosis of DPL is challenging and is often made intraoperatively or through histopathological examination of excised tissues. Reports exist where ovarian cancer with peritoneal dissemination was suspected, leading to treatment based on ovarian cancer protocols [7]. In addition, patients have initially presented to nongynecological departments and were ultimately diagnosed with DPL [8].

There are no prior reports of DPL being newly diagnosed in association with fibroid torsion. Although a few isolated publications have described acute abdomen in the context of DPL or related conditions, including a case of acute abdomen reported by Wijesinghe [5] and a case of omental torsion reported by Tan [6], none of these involved uterine fibroid torsion as the precipitating event. Therefore, the present case represents an exceptionally rare clinical scenario. In cases of acute abdomen, preoperative imaging is often insufficient, especially when multiple uterine fibroids occupy the pelvic cavity and obscure small peritoneal nodules. If peritoneal dissemination is detected intraoperatively, malignancy should be the primary consideration and a thorough intra-abdominal examination is essential. Appropriate surgical strategies must be determined on the basis of the clinical course and intraoperative findings. Therefore, it is important to consider DPL in the differential diagnosis when peritoneal dissemination is observed [4]. Intraoperatively, distinguishing DPL from malignancy is often difficult, and careful assessment of lesion morphology, distribution, and consistency is essential; when malignancy cannot be excluded, intraoperative frozen section may be helpful. Although frozen section was unavailable in this nighttime emergency, its use could potentially help avoid more extensive or overly invasive surgical procedures.

Clinical reports of DPL in patients without a history of gynecological treatment are extremely rare. Several hypotheses have been proposed to explain the pathogenesis of DPL. The first suggests that undifferentiated mesenchymal cells in the peritoneum differentiate into smooth muscle cells under the influence of sex steroids [3]. The second involves chromosomal abnormalities, with prior studies reporting aberrations such as t(12;14)(q14–q24), del(3q), and r(1)(p34q41) in DPL or leiomyoma-like lesions [9], although genetic testing was not performed in this case because it is not a common clinical testing and the results would not have altered management of the patient. The third suggests that iatrogenic factors such as hormonal therapies, myomectomy, or electromechanical morcellation in the abdominal cavity contribute to the development of DPL [3]. Most reports of DPL have cited iatrogenic factors as the cause, underscoring the importance of obtaining a detailed medical history. However, as observed in the present case, DPL can occur in the absence of known iatrogenic factors.

There are no established treatment guidelines for DPL; however, treatment options similar to those for uterine fibroids are considered effective. Surgical management is not always necessary for asymptomatic patients. Medical treatments, such as gonadotropin-releasing hormone agonists and aromatase inhibitors, have been used with the expectation that suppressing estrogen stimulation may shrink lesions [10]. These hormonal therapies are mainly reported in premenopausal or hormonally active patients, and evidence in postmenopausal women is limited; in this postmenopausal patient with small residual lesions and stable imaging, conservative follow-up was considered appropriate. Surgical treatment, including excision of the lesions or bilateral salpingo-oophorectomy, is an option [10]. Cases of DPL occurring after menopause and those with malignant transformation have also been reported [11, 12]. Long-term follow-up is essential when residual disease is present. In this case, surveillance consisted of evaluations every 6–12 months with annual CT imaging, with follow-up decisions individualized according to symptoms, menopausal status, and imaging stability.

Conclusion

When peritoneal dissemination is incidentally identified during surgery, DPL should be considered in the differential diagnosis along with malignant tumors. Detailed intra-abdominal examinations and appropriate surgical decision-making are crucial. DPL may occur in patients without a history of gynecological treatment. The present case demonstrates that DPL can rarely present with acute abdomen due to fibroid torsion, and highlights the importance of considering this entity even in unexpected emergency settings.

Abbreviations

CT

Computed tomography

DPL

Disseminated peritoneal leiomyomatosis

H & E

Hematoxylin and eosin

α SMA

α smooth muscle actin

Author contributions

KW and TK managed the patient and wrote the manuscript. YT and AT gave advice in managing the patient. YT and HF gave advice in preparing the manuscript. All authors agree with the content of the manuscript.

Funding

None to declare.

Data availability

Not applicable.

Declarations

Ethics approval and consent to participate

This retrospective case report was conducted in accordance with the Declaration of Helsinki. Formal review and approval by an ethics committee were not required, in accordance with our institutional policy. Written informed consent was obtained from the patient for publication.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

The authors declare that they have no competing interests.