A 30-year-old woman, 29 weeks pregnant (G1P0), presented with progressive right-sided pleuritic chest discomfort and dyspnea for 1 week in duration. One month prior to her presentation, the patient went kayaking in the Mohawk River Valley, upstate New York. She noticed an enlarging right anterior chest mass that developed after a wooden oar inadvertently struck her during the outing. She was seen by the primary care physician 10 days prior to admission and was given a short course of dexamethasone for presumed costochondritis.