Circulating tumor cells clusters and their role in Breast cancer metastasis; a review of literature.

Breast cancer is a significant and deadly threat to women globally. Moreover, Breast cancer metastasis is a complicated process involving multiple biological stages, which is considered a substantial cause of death, where cancer cells spread from the original tumor to other organs in the body-representing the primary mortality factor. Circulating tumor cells (CTCs) are cancer cells detached from the primary or metastatic tumor and enter the bloodstream, allowing them to establish new metastatic sites. CTCs can travel alone or in groups called CTC clusters. Studies have shown that CTC clusters have more potential for metastasis and a poorer prognosis than individual CTCs in breast cancer patients. However, our understanding of CTC clusters' formation, structure, function, and detection is still limited. This review summarizes the current knowledge of CTC clusters' biological properties, isolation, and prognostic significance in breast cancer. It also highlights the challenges and future directions for research and clinical application of CTC clusters.

Spontaneous Vertebral Artery Dissection Is an Under-Recognized Cause of Stroke in Young Patients: Two Case Reports and Review.

Cervicocerebral artery dissection (CAD) is an important and under-recognized cause of strokes in young and middle-aged patients. Spontaneous vertebral artery dissection (VAD) is a rare condition that can potentially cause a stroke without any preceding trauma or other causes of dissection. VAD rarely simulates classical headache syndromes. In this report, we discuss two young patients who were initially misdiagnosed as cases of headache until they presented with ischemic events, and were eventually diagnosed with spontaneous VAD. Case 1 involves a 41-year-old male patient who presented with severe headache radiating to left posterior neck pain and dizziness. He was initially misdiagnosed as a case of cervicogenic headache. He was subsequently diagnosed with extracranial VAD complicated by a delayed embolic ischemic stroke. However, he made full recovery within the next few days. Case 2 pertains to a 33-year-old female patient who presented with right-sided headache mimicking migraine; later on, new neurological signs prompted a diagnosis of acute ischemic infarction as a complication of intracranial VAD. In conclusion, VAD should be seriously considered when dealing with patients complaining of the first attack of headache that mimics migraine or those with cervicogenic headaches, which fail to respond to the usual treatment. Moreover, posterior circulation stroke among young patients or stroke with pain in the head and neck should be investigated carefully with extensive neuroimaging. Finally, prompt and accurate diagnosis of VAD followed by proper treatment is crucial for good outcomes and will prevent disability or even fatal complications in patients.