Spinal collision lesions

Bone Metastasis from Renal Cancer Coinciding with the Same Anatomical Position as a Vertebral Hemangioma: A Collision Lesion Case Report

Collisions lesions are rare neoplasms where two histologically distinct tumors coexist in the same organ or anatomical site. Vertebral hemangiomas (VHs) are the most common lesions involving the vertebral bodies and imaging findings of typical and atypical hemangiomas, variant forms of hemangioma such as aggressive hemangiomas are well known, but collision lesions involving VHs are extremely rare. This article presents a case report of a 73-year-old male patient diagnosed with clear cell renal cancer in a rare presentation of a bone metastasis coinciding with the same anatomical position as a VH (collision lesion). This required a multidisciplinary approach involving various diagnostic techniques to determine the best therapeutic management.

Primary Benign Neoplasms of the Spine

Benign tumours comprise the majority of primary vertebral tumours, and these are often found incidentally on imaging. Nonetheless, accurate diagnosis of these benign lesions is crucial, in order to avoid misdiagnosis as more ominous malignant lesions or infection. Furthermore, some of these tumours, despite their benign nature, can have localised effects on the spine including neural compromise, or can be locally aggressive, thus necessitating active management. Haemangiomas and osteomas (enostosis) are the commonest benign tumours encountered. Others include osteoid osteoma, osteoblastoma, fibrous dysplasia, osteochondroma, chondroblastoma, haemangioma, simple bone cysts, aneurysmal bone cysts, giant cell tumours, eosinophilic granuloma and notochordal rests. The majority of lesions are asymptomatic; however, locally aggressive lesions (such as aneurysmal bone cysts or giant cell tumours) can present with nonspecific symptoms, such as back pain, neurological deficits and spinal instability, which may be indistinguishable from more commonly encountered mechanical back pain or malignant lesions including metastases. Hence, imaging, including radiography, computed tomography (CT) and magnetic resonance imaging (MRI), plays a critical role in diagnosis. Generally, most incidental or asymptomatic regions are conservatively managed or may not require any follow-up, while symptomatic or locally aggressive lesions warrant active interventions, which include surgical resection or percutaneous treatment techniques. Due to advances in interventional radiology techniques in recent years, percutaneous minimally invasive techniques such as radiofrequency ablation, sclerotherapy and cryoablation have played an increasing role in the management of these tumours with favourable outcomes. The different types of primary benign vertebral tumours will be discussed in this article with an emphasis on pertinent imaging features.

A 68-Year-Old Woman with a Remote History of Breast Cancer Presenting with Low Back Pain to a Chiropractic Clinic in Hong Kong with Imaging Findings Consistent with a Vertebral Hemangioma and Vertebral Metastatic Lesions

BACKGROUND Patients commonly visit chiropractic clinics for treatment for low back pain, which is often due to injury or degenerative spinal conditions. Rarely, serious underlying pathology may be identified. This report describes a 68-year-old woman with a remote history of breast cancer presenting with low back pain to a chiropractic clinic in Hong Kong with imaging findings consistent with vertebral hemangioma and vertebral metastatic lesions. CASE REPORT A 68-year-old woman with a history of breast cancer status after chemotherapy and mastectomy 20 years prior presented to a chiropractor with an acute exacerbation of chronic low back pain with lower extremity paresthesia. She previously visited her general practitioner and underwent radiography, which supported diagnoses of degenerative lumbar spondylosis and hemangioma of the fifth lumbar vertebra. Given the patient's worsening status and previous cancer, the chiropractor ordered lumbar magnetic resonance imaging at the initial visit, consistent with multilevel spinal metastasis. The chiropractor referred the patient to an oncologist who performed positron emission tomography/computed tomography, which suggested breast cancer recurrence and metastasis. The greatest hypermetabolic activity was evident within the level of the suspected vertebral hemangioma, suggesting this finding which initially appeared innocuous on plain radiography contained underlying metastasis. CONCLUSIONS This case illustrates that when patients fail to respond to treatment for low back pain, clinical referral should be undertaken for investigations to identify possible serious underlying pathology.

"Do-not-touch" lesions of bone revisited

Incidental bone lesions are encountered frequently in day-to-day practice. Many of these lesions are indeterminate requiring referral to specialist centres for further characterisation with or without biopsy; however, as biopsy has its own drawbacks, not all lesions can be subjected to biopsy. The primary role of a radiologist in these situations is to characterise these lesions based on their imaging appearances into aggressive lesions requiring biopsy and non-aggressive lesions that do not require a biopsy. The term "do-not-touch lesion" is used to describe a lesion with typical radiographic appearances that can be characterised based on radiographic appearances alone without needing a biopsy. With recent advances in imaging, many incidental lesions can be characterised into do-not-touch lesions based on their imaging appearances alone using a single imaging technique or using a combination of imaging techniques and, less frequently, with the additional help of serological investigations, without the need for biopsy. Hence, the definition of do-not-touch lesions of bone needs a revisit. In this article, we attempt to redefine do-not-touch lesions of bone and propose an imaging-based classification for characterisation of these lesions.