The small triangular epicardial fat pads which are so frequently seen in postero-anterior chest films at the cardiac apex, where they normally mask the blunt tip of the apex and fill in the left cardiophrenic angle, are now well known. A larger form, which may be found in the right as well as the left cardiophrenic angle, in spite of several published descriptions (1–3), is less readily identified by radiologists generally. Holt, in particular, described the roentgen characteristics of this deposit as observed in a series of probable cases. He demonstrated several conditions of pathological import closely mimicked by the epipericardial fat pad roentgenologically and stressed the importance of a differential diagnosis. In order further to develop the roentgen features of the condition and to facilitate its recognition, we are reporting here a case of epipericardial fat pad explored first by tomography and later at thoracotomy. Relatively few such cases have been definitely identified, since this can be done only in the event of a fortuitous thoracotomy undertaken for some other reason, or on postmortem examination. Case Report A. N., a 32-year-old white male, who was discovered to have pulmonary tuberculosis with a right infraclavicular cavity on May 2, 1946, was admitted to a sanatorium on May 13, 1946, where he was treated by right pneumothorax and intrapleural pneumonolysis. He was considered “arrested” and was discharged on Dec. 3, 1946. He did well until Feb. 20, 1953, when a routine follow up film showed a small area of fresh disease in the left apex. Following admission to a hospital, this lesion gradually resolved. Recently, x-ray examination had revealed an apparently typical tuberculoma in the right upper lung field. Tomographic examinations in July 1953, undertaken because of recurrence of positive sputum, suggested a small possible breakdown within the tuberculoma and it was decided to resect this lesion both as a possible source of the organisms in the sputum and a potential future hazard. It was about this time that right lateral tomography clearly demonstrated a triangular shadow in the right lower anterior thorax which subsequently proved to be an epipericardial fat pad. On Dec. 28, 1953, a segmental resection of the posterior segment of the right upper lobe was performed. The surgeon, alerted to the triangular radiopacity previously described, reported it to represent an epipericardial fat pad lying in the angle formed by the diaphragm, anterior chest wall, and pericardium. A photograph of the structure through the operative incision is shown in Figure 1. Discussion From Holt's article, it is possible to gather some of the roentgen characteristics of large right-sided epipericardial fat pads.