Capricious Radiographic Presentations of Pulmonary Benign Metastasizing Leiomyoma Raise Diagnostic Challenges

Abstract

ABSTRACT

Pulmonary benign metastasizing leiomyoma (PBML) cases are often asymptomatic and exhibit various imaging patterns, posing diagnostic challenges and frequently mimicking malignancies or other atypical histologies. Herein, we present three cases of PBML in women, each with distinct radiographic features, all managed through surgical interventions. These cases underscore the importance of early detection for prompt diagnosis and treatment. Furthermore, they highlight the need to consider PBML as a differential diagnosis in women with a history of uterine leiomyoma presenting with indeterminate lung masses and diverse radiographic findings.

Introduction

Benign metastasizing leiomyoma (BML) is a condition mostly found in women. The prevalence of BML remains unestablished due to its rarity and mostly asymptomatic nature. BML is often found incidentally, representing leiomyomas extending beyond the uterus, with the lungs being the primary metastasis site [1]. Pulmonary benign metastasizing leiomyoma (PBML) cases are mostly asymptomatic, leading to misdiagnosis as cancer metastasis and pneumonia due to challenges in diagnosis through examinations [2, 3]. Thus, we present three cases of PBML with diverse radiographic features, all of which underwent surgery. This emphasises the importance of early recognition to enable prompt diagnosis and treatment.

Case Series

Case 1

A 46-year-old woman with no underlying medical conditions visited our hospital due to lower abdominal pain. During a sonography examination, a cystic lesion was observed in the uterus, and diagnostic surgical intervention was organised. Consequently, a preoperative chest x-ray image revealed bilateral miliary nodules (Figure 1A). Subsequent CT images indicated multiple poorly enhancing solid nodules in both lobes (Figure 1B). Therefore, a combined operation, which included a hysteroscopic uterine tumour biopsy and video-assisted thoracoscopic surgery (VATS) was conducted (Figure 1C,D).

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The subsequent pathological report and the immunohistological staining of lung nodules suggested a diagnosis of PBML and uterine leiomyoma (UC). Over the subsequent 4 years, she underwent regular outpatient clinic follow-ups with Leuprorelin, during which CT images revealed stable disease of the remaining lung nodules.

Case 2

A 53-year-old woman, who had a total abdominal hysterectomy for uterine leiomyoma (UC) 7 years ago, is now diagnosed with Stage IVB nasopharyngeal cancer (NPC). The additional staging assessment through chest CT imaging disclosed bilateral lung nodules, raising concerns about potential lung metastases. Subsequently, she underwent chemotherapy regimens involving Gemcitabine (1400 mg) and Cisplatin (30 mg/m²) for 4 months; However, persistent lung nodules remained evident on the CT images (Figure 2A–D), despite the notable shrinkage of NPC observed in the Magnetic resonance images (MRI). Due to the reasons above, she was referred to the chest surgeon, where one-stage right VATS and left minithoracotomy metastasectomies were performed (Figure 2E,F).

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The pathology report indicated that three out of the four specimens were PBML (Figure 3A) and the other was benign focal interstitial fibrosis. Immunohistochemical staining of these specimens further confirmed the diagnosis of PBML (Figure 3B–D). There was no observed recurrence of PBML over a span of 3 years postoperatively. The patient has been undergoing a radiotherapy regimen for NPC, with no evidence of disease progression.

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Case 3

A 51-year-old woman, who had a total abdominal hysterectomy a decade ago due to uterine leiomyoma (UC), presented with an incidentally discovered mass on chest x-ray images (Figure 4A). The patient denied any discomfort. Subsequent CT examination revealed a cavitated hyperdense lesion (Figure 4B) and multiple nodules (Figure 4D). Suspecting aspergilloma and lung metastasis, left VATS S9+10 segmentectomy and wedge resection of the left upper lung were performed (Figure 4C). The gross appearance of the lesion was elastic, white-tan colour, and well demarcated (Figure 4E). Both the pathological report and the immunohistochemical staining supported the diagnosis of PBML. Following the operation, the patient has been undergoing routine follow-up at the outpatient clinic with a stable condition for 10 months.

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Discussion

Asymptomatic pulmonary nodules in patients with a history of uterine pathology or prior gynaecological surgery should raise suspicion for PBML. In this study, none of the three patients presented with pulmonary symptoms. The first patient had a cystic uterine lesion, while the other two had undergone total abdominal hysterectomy for uterine leiomyoma approximately 10 years prior to the incidental discovery of their PBML.

Previous research, such as the study by Miller et al., reported symptoms in approximately 30% of patients and prior gynaecological surgery in 80%, with a median interval of 23 years between the primary uterine pathology and PBML diagnosis [3]. These three cases underscore the importance of considering PBML as a differential diagnosis in patients with a history of gynaecological disease, even in the absence of pulmonary symptoms. In our study, these cases highlight the need for vigilance when evaluating patients with underlying gynaecological conditions, as this may facilitate the timely diagnosis of PBML.

Furthermore, previous studies have also indicated that CT images of PBML exhibited various patterns [4, 5]. The diversity of patterns was also observed in our three cases, including bilateral diffuse miliary patterns, multiple nodules suspecting metastases, or solitary cavitated masses. The first two cases had CT images resembling malignant metastasis, particularly when considering their underlying disease. In the third case, the irregular mass with cavitation resembles characteristics often associated with aspergilloma. Various CT image patterns of PBML can increase the challenges of diagnosis.

On the other hand, prompt operation can assist diagnosis of PBML. Following the operation, stable disease was observed in these patients, aligning with findings from a prior study by Miller et al. In their study, 72% of patients maintained stable disease during the three-year follow-up period after the operation [3]. Disease progression after operation was shown to be indolent, indicating the benign nature of PBML. Thus, the operation can be considered as a diagnostic tool in selected patients to avoid inappropriate treatment direction and delayed care.

PBML is an unusual and often asymptomatic disease. In the differential diagnosis of lung lesions, particular attention should be given to female patients with a history of uterine leiomyoma. Consideration of surgical intervention in selected patients may be warranted. Further studies are needed to explore the general incidence of PBML in the female population and the diversified imaging patterns, thereby allowing clinicians to prompt optimal management.

Author Contributions

Chao-Hsin Huang and Yu-Wei Liu contributed to the conception of the study, interpretation of the data, and drafting of the manuscript. Chieh-Ni Kao, Kun-Bow Tsai, Ping-Ruey Chou, and Shah-Hwa Chou contributed to the interpretation of the data and revision of the manuscript. All the authors critically reviewed and approved the final version of this manuscript.

Ethics Statement

The authors declare that appropriate written informed consent was obtained for the publication of this manuscript and accompanying images.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

References

E. Barnas, M. Ksiazek, R. Ras, A. Skret, J. Skret‐Magierlo, and E. Dmoch‐Gajzlerska, “Benign Metastasizing Leiomyoma: A Review of Current Literature in Respect to the Time and Type of Previous Gynecological Surgery,” PLoS One 12, no. 4 (2017): [eLocator: e0175875], [DOI: https://dx.doi.org/10.1371/journal.pone.0175875].