The specimen is received unfixed labeled "right atrial mass". It consists of a 58 gram, firm, opaque, gray-yellow mass with a small portion of tan trabecular atrial tissue visibe. The total specimen measures 6.6 x 5.3 x 4.6 cm. The serosal aspect is diffusely hemorrhagic. Upon sectioning there is a soft, focally necrotic gray-white nodular tumor, measuring 5.8 x 3.6 x 3.5 cm. The tumor has infiltrating borders and is extensively necrotic and hemorrhagic. The atrial tissue adjacent to the mass is pink-tan, firm and somewhat gelatinous. The surface is inked and representative sections are submitted in cassettes B through E with cassette 1A being saved for DNA. Tumor is submitted for cytogenetics, frozen in OCT and in bulk, submitted for EM and DNA studies.