A 57–year–old man presented acutely after being awoken from sleep with shortness of breath. He had no associated or prodromal symptoms, and no gastrointestinal complaints. Review of systems revealed significant weight loss, with waist size decreasing from 42 to 32 inches in 3 years. There was no family history of malignancy. Vital signs, physical examination, laboratory studies, and electrocardiogram (EKG) upon presentation were all unremarkable. Admission chest radiograph suggested an enlarged cardiac silhouette and small bilateral pleural effusions. Transthoracic echocardiogram discovered a large circumferential pericardial effusion with signs of hemodynamic compromise. Emergent pericardiocentesis removed 750 mililiters of straw–colored fluid. Serologic and pericardial fluid testing for infectious pathogens were negative. Computed tomography (CT) scan of the chest was without evidence of intrathoracic malignancy. Abdominal CT identified a focal necrotic rim–enhancing mass involving the ileocecal junction and cecum. Pericardial fluid cytology returned positive for malignant adenocarcinoma, with immunohistochemical staining suggestive of a gastrointestinal source. Colonoscopy visualized a nearly–obstructing mass in the proximal ascending colon, with biopsy positive for moderately differentiated colon adenocarcinoma. Surgical window was ultimately required for recurrence of the pericardial effusion. The patient was discharged to pursue a second opinion at another institution, and passed away 4 months after his initial diagnosis of cancer.
All pericardial effusions require a thorough diagnostic evaluation. Malignant pericardial effusion (MPE) is common (13–44% in various series), and is the most frequent cause of pericardial effusion and tamponade in tertiary academic medical centers. MPE also often yields the diagnosis of a previously unrecognized cancer, estimated at 18% in hemodynamically significant effusions. Malignancies of the lung are most common, while a gastrointestinal source is infrequent in MPE. In the clinical assessment of pericardial effusion, the absence of hallmark features (chest pain, friction rub, fever, characteristic EKG findings) has been associated with a greater likelihood of MPE. While cytology can be a useful tool in the diagnosis of MPE, it is far from the gold standard. Sensitivities of cytology for MPE in multiple case series range from 50–90%. When present, abnormal cytology in MPE is associated with a reduction in median survival from 15 to 7 weeks, and an increased need for repeat pericardiocentesis or pericardial surgery.
MPE as the initial manifestation of a disseminated malignancy is not a rare event, though the colonic origin of this malignancy certainly was. Clinicians should be aware of the prevalence of MPE, especially as an initial presentation of cancer to facilitate rapid diagnosis and prompt treatment for patients who desire it.