Non Traumatic Rupture of Splenic Metastases as the First Presentation of Clinically Occult Disseminated Primary Lung Cancer

Key Learning Points • Though ruptured aortic aneurysm is one of the commonest causes of sudden hypovolemic shock in an adult male, an urgent abdominal CT angiography is recommended for confirmation of diagnosis as it may occasionally reveal an intact aorta with other unexpected causative factors such as an unsuspected splenic rupture. • Non traumatic splenic rupture is rare and is usually associated with a ‘pathological’ spleen with underlying infectious or neo plastic lesions which are usually primary hemopoietic in nature with secondary metastases being relatively uncommon. • Metastases to the spleen from visceral organs is extremely infrequent (<5%) with breast, lung, pancreas, ovary, melanoma and choriocarcinoma often being attributed as their primary source. • Though lung cancer is a commonly diagnosed cancer in Canada with many being diagnosed at an advanced stage, non-traumatic rupture of splenic metastases is an extremely rare first time clinical presentation of primary occult disseminated lung cancer. 1. Abstract In Canada, lung cancer is one of the most commonly diagnosed cancers and is the leading cause of cancer related death. Unfortunately, more than half of all lung cancers present at an advanced stage and are often metastatic at diagnosis. The common sites of metastases include the brain, bone, liver, adrenals, opposite lung and distant lymph nodes. The spleen, a hemopoietic organ is an extremely uncommon site of metastases. In the setting of lung cancer, splenic metastases occurs in the context of disseminated disease, or uncommonly presents as a solitary metastases that is often detected on radiological image surveillance. Most of these scenarios occur in the background of known lung cancer disease. In this case report, we share a case of non-traumatic rupture of splenic metastases whose clinical presentation mimicked a ruptured abdominal aneurysm. The presentation of non-traumatic rupture of the splenic metastases arising from an occult disseminated primary lung cancer as the first clinical encounter is extremely rare and to our knowledge has not been previously reported. Increased clinical awareness of this extremely uncommon clinical presentation of an underlying common disease is important as rapid diagnosis can significantly reduce major morbidity and mortality. 2. Case Presentation A 63-year-old male presented to the community hospital with a one hour history of sudden onset of central abdominal pain, nausea, vomiting and diarrhea accompanied by shortness of breath. On examination, his abdomen was mildly distended with signs of peritonism. His past medical history included a remote repair of an inguinal hernia and was otherwise unremarkable. While being transferred to a larger referral center for further workup and investigations, he unfortunately went into cardiac arrest requiring cardiopulmonary resuscitation. He was intubated on arrival at the emergency department as he was hemodynamically unstable and in acute hypovolemic shock. Vascular surgery was consulted for a suspected ruptured abdominal aortic aneurysm.