Not All Hilar Adenopathy is Sarcoidosis: A Rare Case of Mediastinal and Hilar Lymph Node Metastasis in Cervical Squamous Cell Carcinoma

Abstract INTRODUCTION: Uterine cervical cancer is the fourth most common malignancy among women globally. The majority of metastases occur in the pelvis (pelvic and para-aortic lymph nodes). Distant pulmonary metastases are rare. This case report presents an uncommon occurrence of uterine cervical cancer with distant pulmonary metastases after receiving multimodal therapy. It also highlights the role of endobronchial ultrasound (EBUS) with fine needle aspiration (FNA) in confirming the diagnosis. CASE PRESENTATION: A 39-year-old-female presented with abnormal uterine bleeding. She was diagnosed with human papilloma virus (HPV)-associated stage III squamous cell carcinoma (SCC) of the uterine cervix. Imaging revealed bilateral pelvic and retroperitoneal lymphadenopathy, plus a right iliac crest metastasis. She underwent definitive treatment with external beam radiation therapy, brachytherapy, and concurrent chemotherapy with immunotherapy (cisplatin and pembrolizumab). Post-treatment positive emission tomography-computed tomography scan showed an adequate treatment response in the cervix and pelvis. However, it also revealed multiple new bilateral hypermetabolic mediastinal and hilar lymphadenopathy, plus bilateral lung nodules. Bronchoscopy with EBUS was performed with FNA of lymph node stations 4R and 7. Pathology revealed HPV-associated poorly differentiated carcinoma consistent with the patient's known SCC of the cervix. DISCUSSION: Cervical cancer is the fourth leading cause of cancer-related death in women. It commonly metastasizes by local invasion to the pelvic and para-aortic lymph nodes. Metastasis to the thoracic lymph nodes is rare (1% of cases) and when unrecognized can lead to inadequate initial therapy. The mechanism of spread is through lymphatic and hematogenous routes. To our knowledge this is the first case of SCC of the cervix with thoracic lymphadenopathy diagnosed by EBUS-FNA. The literature reported patients with cervical cancer who presented with dysphagia or hemoptysis that were ultimately diagnosed with metastases of the mediastinal lymph nodes by transesophageal endoscopic ultrasound-FNA. EBUS-FNA is a minimally invasive procedure that enables biopsy of mediastinal and hilar lymph nodes. It has a sensitivity of 68.4% and a specificity approaching 100%. This technique has been shown to reduce the need for invasive procedures such as surgical biopsy in 50.3% of patients. This case is notable for a rare occurrence of cervical cancer metastasizing to thorax even after definitive multimodal therapy. Providers should remain vigilant of unusual metastatic sites of cervical cancer. Additionally, this case highlights the value of EBUS-FNA in diagnosing thoracic adenopathy, providing a minimally invasive and highly effective method for confirming metastatic disease.