A case study of the treatment of a rare germ cell tumor in Taiwan was published in the international medical journal 'Lancet' earlier this year and could serve as a reference for other doctors, Taipei Mackay Memorial Hospital said Wednesday in a press conference. The patient, a 33-year-old male with an unremarkable medical history, was admitted to the hospital's emergency room with sudden chest pain, left shoulder pain, and cold sweats while sleeping, said Lai Yau-huei, an attending cardiologist at Mackay. His symptoms resembled those of a heart attack, but when tests did not reveal typical indicators for heart disease, the hospital resorted to a multidimensional echocardiogram -- a kind of cardiac ultrasound -- and found a mass encroaching on the pulmonary artery. The mass was diagnosed as malignant seminoma, a germ cell tumor normally found in the male gonads but which also appears on rare occasions in the anterior mediastinum, the front part of the chest between the lungs. Lai said that in emergency situations where a compression was caused by a tumor, a quick diagnosis was crucial. The patient was cured after four chemotherapy treatments in a three-month period, said Lai, but the patient will need to return for regular checkups because the therapeutic recommendations for this class of germ cell tumor are constantly being revised. The case study, which Lai believed could serve as a valuable reference to other doctors with patients exhibiting similar symptoms, appeared in Lancet in April but was only brought to the public's attention by the hospital on Wednesday. 