A 56 year-old male smoker patient with verified non-small cell lung cancer (NSCLC) was complaining of pain in the upper part of the thigh.
Whole body planar bone scan and SPECT/CT of the area from calvaria to proximal one-third of the shin were performed 2 hours after intravenous injection of 740 MBq Tc99m-MDP. Planar bone scan showed elongated lesion of increased radiotracer uptake in proximal one-third diaphysis of the right femur with central well-defined photopenic defect at posterior projection. Additionally, a heterogeneous area of increased radiotracer uptake was detected in the supraspinatus part of the left scapula. Other areas of abnormal radiotracer uptake, which could be evidence of tumour lesion were not detected. SPECT/CT showed osteolytic lesions with full thickness cortex destruction, extraosseous soft tissue component propagation, in the femur with moderate intramedullary spread, periosteal reaction in the form of “Codman triangle” and increased radiotracer uptake at the periphery of bone defect. Morphological verification, including IHC test, was performed. According to IHC findings, the identified lesion presented bronchogenic carcinoma metastasis.
Bone is one of the most common sites of distant metastases from cancer. Breast cancer, prostate cancer, lung cancer and renal cell carcinoma are the site of origin of 80% bone metastases [1]. Lung cancer is the third most frequent site of origin of skeletal metastases, after breast and prostate cancer. Bone is a common site of metastatic deposits from NSCLC (20–40%) [2]. Spine is the most frequent site of bone metastases. Other common sites are pelvis, proximal humerus, ribs, skull and 6% in femur [3].
Isolated cortex destruction is not a typical pattern of metastatic bone lesions. It is rarely mentioned in medical literature and reveals itself in solitary or multiple lesions of long bones, which can be the first indication of a malignant process [4]. Primaries in lung, breast, kidney and pancreas are causes of cortical metastases [5]. Some authors consider this metastatic pattern as typical for bronchogenic carcinoma, pointing at the typical localization at femoral diaphysis and defining 4 types of lesion: small cortical destruction-"cookie-bite" or "cookie-cutter" lesions, large osteolytic cortical lesions, saucerized intracortical lesions with well-defined periosteal reaction, and lesions with predominant cortical destruction extending into the soft tissue as well as the medullary cavity [6, 7]. A group of autors reported a case of a solitary femur metastatic cortex destruction lesion of a patient with NSCLC [8]. They had analog results of the planar bone scan and SPECT/CT. Pathogenesis of this type of metastatic lesion is not clearly defined. Considering the arterial blood supply of the cortex, which originates from a periosteum vasculature communicating with the bone nutrient artery basin, an isolated cortex lesion may take place, beside a secondary cortex involvement at a primary marrow lesion.
Bone metastases may be the first manifestation of cancer. It is necessary to keep in mind that there are different types of metastatic bone lesions, including cortex metastases.
Femoral cortical metastasis from NSCLC.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
1. The provided femoral X-ray shows partial destruction of the femoral cortical bone, presenting as a localized radiolucent area with a clearly abnormal boundary compared to the surrounding cortex.
2. Bone scan (planar and SPECT/CT) demonstrates abnormal radiotracer uptake at the proximal metaphyseal-diaphyseal region or the metaphyseal-diaphyseal junction of the affected femur, indicating active bone metabolism or lesion activity; corresponding findings are also observed in the primary lung site.
3. CT images of the lesion indicate focal cortical destruction, with partial involvement of the adjacent soft tissues. The local bone marrow cavity involvement is not prominent or relatively minimal, consistent with a “cortical solitary” or “cortically dominant” destructive lesion pattern.
The patient has a confirmed diagnosis of non-small cell lung cancer (NSCLC), and distant bone metastasis is relatively common in lung cancer. Imaging shows local cortical destruction in the metaphyseal region of a long bone, a typical feature of “cortical-type” metastasis from lung cancer.
Such as renal carcinoma, breast carcinoma, or other solid tumors. However, given the patient’s established history of NSCLC, these possibilities are considered lower priority.
Without a confirmed tumor history, one should consider primary bone tumors (e.g., osteosarcoma, chondrosarcoma) or multiple myeloma. However, due to the patient’s known history and the lesion characteristics consistent with metastatic disease, these diagnoses are less likely.
Based on the patient’s existing history of NSCLC, clinical symptoms (proximal thigh pain), and imaging findings (peripheral cortical lytic destruction with high metabolic activity on bone scan), the most likely diagnosis is femoral cortical bone metastasis secondary to NSCLC.
If there is still uncertainty, a histopathological biopsy can be considered for a definitive diagnosis, or additional imaging and laboratory tests (e.g., tumor markers, PET-CT, etc.) can be performed for further confirmation.
1. Treatment Strategy:
(1) Local Treatment: If there is a risk of fracture or signs of impending fracture, prophylactic internal fixation or postoperative bone cement augmentation may be considered to alleviate pain and prevent pathological fractures.
(2) Systemic Pharmacotherapy: This may include chemotherapy, targeted therapy, immunotherapy, or radiotherapy, depending on NSCLC subtype and genetic testing results.
(3) Bone-Protective Therapy: Use bisphosphonates or RANKL inhibitors (e.g., denosumab) to slow bone resorption and prevent new skeletal-related events.
(4) Pain Control and Symptomatic Management: Provide oral or topical analgesics based on pain severity, along with adequate nutrition and basic supportive care.
2. Rehabilitation/Exercise Prescription:
Disclaimer:
This report provides a reference-based analysis based on current imaging and patient history and cannot replace direct consultation or professional medical advice. A specific treatment plan should be developed by a clinical physician in conjunction with the patient’s actual condition.
Femoral cortical metastasis from NSCLC.
