What happened, in summary

This 68-year-old Caucasian man had a history of squamous cell lung cancer diagnosed 3 years before his first vascular presentation. The original cancer was T4N2M0 and was found after workup for recurrent laryngeal nerve palsy. Histology showed squamous carcinoma with p40 positivity, TTF-1 negativity, and no PD-L1 expression reported. He received curative-intent chemoradiotherapy with 6 cycles of carboplatin and paclitaxel plus 60 Gy in 30 fractions. After a radiologic and histologic recurrence about 1 year later, he started pembrolizumab 200 mg every 3 weeks; durvalumab had been avoided because he also had systemic lupus erythematosus. By December 2021, after 18 pembrolizumab cycles, he suddenly developed left hand pain and discolored fingers. CT angiography showed left brachial artery occlusion extending into the radial and ulnar arteries. Heparin was started, embolectomy restored perfusion, and pathology showed the embolus was malignant and consistent with his lung cancer. He was discharged on warfarin. Eight months later, despite therapeutic anticoagulation, he developed sudden bilateral lower-limb pain and discoloration. CT angiography showed bilateral popliteal artery occlusions. He underwent bilateral lower-limb embolectomies and left 4-compartment fasciotomy; pathology again confirmed tumor emboli. Before discharge, new seizures led to brain MRI, which showed cerebral metastases. He received whole-brain radiotherapy for symptom management and later transitioned to community rehabilitation. He died from advanced disease 7 months after the bilateral limb ischemia presentation. The vascular events were important because both operations retrieved tumor material rather than ordinary clot alone, showing that the cancer itself was driving repeated arterial emboli despite anticoagulation.