Abstract
Spinal lesions in patients with breast cancer are often presumed metastatic; however, benign insufficiency fractures can closely mimic metastatic disease, creating a diagnostic challenge. We report the case of a 52-year-old female with estrogen receptor-positive, progesterone receptor-positive, and HER2-negative (ER/PR+, HER2−) metastatic breast cancer to the liver who presented with severe back pain and peripheral numbness. Imaging revealed bilateral pedicular insufficiency fractures at the level of L3 and L4 vertebral bodies. The pedicular fractures demonstrated imaging features favoring insufficiency etiology, likely therapy- or osteopenia-related, with metastatic involvement considered unlikely. This case emphasizes how important it is to take nonmetastatic etiologies into account when assessing new spinal lesions in patients with cancer. Accurate differentiation between metastatic and nonmetastatic fractures using detailed imaging assessment is crucial to prevent unnecessary changes in cancer management.
Keywords: Breast cancer, Pedicular fracture, Insufficiency fracture, Nonmetastatic, Spine, Bilateral stress fracture
Introduction
Bilateral pedicular fractures are considered rare spinal injuries often mistaken for metastatic lesions, particularly in patients with a history of malignancy [1]. We report a case of bilateral pedicular fractures in a patient with a history of osteoporosis and metastatic breast cancer. This case highlights the importance of considering benign causes, such as insufficiency fractures or stress fractures, when evaluating new spinal lesions in oncology patients.
Case presentation
History
A 52-year-old Saudi female with a known case of ER/PR+, HER2−, metastatic left breast cancer to the liver presented with severe back pain for 3 weeks, associated with peripheral numbness. There were no symptoms of urinary or fecal incontinence. She had previously undergone a modified radical mastectomy with axillary lymph node dissection, followed by adjuvant AC+T chemotherapy and tamoxifen therapy. There was no associated family history or other surgical history. The patient presented initially with a left breast mass. Post biopsy reading showed invasive ductal carcinoma grade III, ER/PR+, HER2. The biopsied axillary lymph nodes show metastatic ductal carcinoma with a BI-RADS 6. The patient received 8 cycles of chemotherapy, the last 1 being 2 years before undergoing a modified radical mastectomy, and has been on tamoxifen since the time of diagnosis. A computed tomography (CT) scan of the whole spine showed diffuse osteopenia and mild cervical and lumbar scoliosis. Osteopenia was confirmed using a bone mineral density (BMD) scan, with BMD values being in the range of osteopenia as per the World Health Organization (WHO) classification, and a T score of -1.9 in the left femoral neck.
Detailed investigations
CT performed for evaluation of new back pain revealed incidental findings of bilateral symmetric pedicular stress/insufficiency fractures at the L3 and L4 vertebrae with minimal displacement (Fig. 1, Fig. 2). The bilateral symmetry, absence of cortical destruction, and lack of associated paraspinal or epidural soft tissue mass were key imaging features supporting a benign etiology. The patient had a history of treated metastatic involvement of the L4 vertebral body, which is noted again, showing post-treatment changes and mild associated scoliosis. No new aggressive or suspicious osseous lesions were identified, and there was no paraspinal or epidural soft-tissue component suggestive of recurrent metastatic disease. The bilateral pedicular fractures were treated conservatively with no surgical involvement. Subsequent bone scan revealed mild irregular uptake in the lower lumbar spine, which could be related to degenerative changes. No other significant focal bone abnormalities were seen on the rest of the whole-body scan. Follow-up CT imaging showed redemonstration of the previously seen L3 and L4 bilateral insufficiency fractures without associated anterolisthesis or changes, and a nonactive L4 vertebral body mixed lytic and sclerotic lesion.
Fig. 1.
Sagittal computer tomography (CT) images of the lumbosacral spine showing bilateral symmetrical pedicular fractures in L4 (A) and L3 (B) vertebral bodies, with absence of destruction (fracture lines represented by arrows).
Fig. 2.
Axial computer tomography (CT) images of the lumbosacral spine showing bilateral non-displaced pedicular fractures in L4 (A) and L3 (B) vertebral bodies represented by dashed lines.
Discussion
In this report, we present a 52-year-old female patient with ER/PR+, HER2− breast cancer metastatic to the liver who had severe back pain and peripheral numbness. A bilateral pedicular fracture was found incidentally during a CT scan of the spine. While insufficiency fractures have been reported in association with metastatic cancers such as breast cancer, leukemia, and osteosarcoma, to the best of our knowledge, no previous reports have described bilateral nonmetastatic pedicular stress or insufficiency fractures in a patient with breast cancer.
Distinguishing insufficiency fractures from metastatic lesions in oncology patients represents a significant diagnostic challenge. In this case, several imaging features favored a benign etiology. The fractures were bilateral and symmetric, a pattern that is uncommon for metastatic disease. Additionally, there was no evidence of cortical destruction, vertebral body involvement, or associated paraspinal or epidural soft tissue mass. These findings, in conjunction with the patient’s known osteopenia and prior systemic therapy, support the diagnosis of insufficiency fractures rather than metastatic involvement.
To the best of our knowledge, no previously published cases matching the clinical and imaging findings of our patient were identified following a review of the literature using PubMed and Google Scholar. However, several studies have reported nonmetastatic fractures in patients with malignancy. In 1992, 2 case reports were published involving patients with fracture-related skeletal complications associated with acute leukemia and osteosarcoma or their therapy [2,3]. Another study reported a pathological compression fracture in a male patient with breast cancer [4]. Additionally, several case reports have described vertebral compression fractures in children with acute lymphoblastic leukemia, occurring both at disease onset and after remission, often in association with osteoporotic changes and pain [5,6].
These reports highlight the occurrence of stress and insufficiency fractures secondary to malignancy or its treatment; however, none have described bilateral nonmetastatic pedicular fractures in patients with cancer, including breast cancer. Therefore, this case contributes to the existing body of knowledge by documenting a previously unreported and unusual fracture pattern.
This case highlights the importance of considering nonmetastatic etiologies for new spinal fractures in oncology patients, particularly in those with known osteopenia or prior systemic therapy that may affect bone quality. Accurate differentiation between metastatic and nonmetastatic fractures is essential to guide management and avoid unnecessary changes in cancer therapy. Our report adds to the limited literature by illustrating an unusual, bilateral pedicular fracture pattern occurring in the absence of metastatic involvement. A limitation of this case is the absence of advanced imaging such as MRI or PET/CT, which may have provided added confirmation in excluding metastatic disease. Therefore, while the CT findings favor a benign cause, metastatic involvement cannot be definitively excluded exclusion of metastatic disease. Although a comprehensive literature search was performed, relevant cases may have been missed because of variations in terminology and indexing.
Conclusion
In conclusion, this case highlights a rare presentation of bilateral pedicular insufficiency fractures in a patient with a history of malignancy. Although nonmetastatic vertebral fractures have been reported in oncology patients, bilateral pedicular involvement appears to be exceptionally uncommon. This case underscores the importance of considering benign fragility fractures in the differential diagnosis of new spinal lesions in cancer patients. Comprehensive radiologic assessment and clinical correlation are therefore crucial to ensure accurate diagnosis and to avoid unwarranted modifications in oncologic management.
Patient consent
The treating physician obtained written informed consent for publication of the case and accompanying images.
Footnotes
Competing Interests: The authors have declared that no competing interests exist.
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