Abstract Single coronary artery is described as an isolated coronary artery originating from the aortic root through a single ostium in the absence of another ostium. The single coronary artery is the only source for blood supply to the whole heart. In this case we present a patient admitted to the outpatient clinic with typical chest pain, whose physical examination indicated accessory mammary tissue without any additional physical examination findings. The patient had hyperlipidemia and hypertension risk factors, and a coronary angiography was planned. The coronary angiography performed on the 72 year old male patient revealed a single coronary artery. According to the angiography, it is reported that the whole coronary system is distributed to the heart from a single trunk originating from the right sinus of valsalva. The multislice computerized tomography showed that the left anterior descending, circumflex and right coronary arteries originated from single trunk at the level of right sinus of valsalva through a single ostium without the left main trunk. There was no additional congenital anomaly. The patient, who had noncritical strictures, was discharged with medical treatment. Neural crest cells, matrix metalloproteinase, epidermal growth factor receptors, vascular endothelial growth factor and receptors are effective in the development of coronary arteries and mammary tissues in the embryonic phase. Any impact on the migration routes of the neural crest cells or distortion of the synthesis of expression products may have caused this kind of an anomaly. Keywords: Coronary artery anomaly, accessory mammary tissue, embryogenesis Ozet Tek koroner arter, aort kokunden tek koroner ostiyum araciligiyla cikan ve ikinci bir ostiyumun gozlenmedigi izole koroner arter olarak tanimlanir. Tek koroner arter butun kalbin kan akiminin saglanmasindan sorumludur. Bu olguda, tipik gogus agrisi nedeniyle poliklinige basvuran, fizik muayenesinde aksesuar meme dokusu olan ve ek fizik muayene bulgusu olmayan bir hasta sunuldu. Hiperlipidemi ve hipertansiyon risk faktorleri olan hastaya koroner anjiyografi planlandi. Yapilan koroner anjiyografide tek koroner arter saptanan 72 yasinda erkek hasta sunuldu. Koroner anjiyografide tum koroner sistemin sag sinus valsalva’dan cikan tek govdeden kalp bolgesine yayilim gosterdigi saptandi. Cokkesitli bilgisayarli tomografide, sol on inen, sirkumfleks ve sag koroner arterlerin sol ana govde olmaksizin tek ostiyum araciligi ile sag sinus Valsalva duzeyinde tek govdeden koken aldiklari izlendi. Ek konjenital anomali izlenmedi. Nonkritik darliklari olan hasta medikal tedavi ile taburcu edildi. Koroner arter ve meme dokusunun embriyonal donemde gelismesinde, noral krista hucreleri, matriks metalloproteinazlar, epidermal buyume faktor reseptorleri, vaskuler endotelyal buyume faktoru ve reseptorleri etkilidir. Noral krista hucrelerinin goc yollarinin etkilenmesi ya da ekspresyon urunlerinin sentezlenmesindeki bir aksaklik bu tur bir anomali olusmasina yol acmis olabilir. Anahtar sozcukler: Koroner arter anomalisi, aksesuar meme dokusu, embriyogenez