<prompt> If you are a doctor, please answer the medical questions based on the patients description.i have a small lump on my 2nd rib below my right breast. I have seen my GP and he is sending me for an ultrasound. I am 16 weeks pregnant and extremely worried it could be a cancerous lump. Is this likely? I am 32 years old and in good health with no background of ill health. There is no history of cancer on my mother s side of the family however my father died of prostate cancer aged 62 .  <response>: Hi.it is best if you have that breast ultrasound done as directed, if you want to know if there is truly a lesion or mass on your breast. It is safe even for your pregnancy. If further investigation will be needed such as mammography, abdominal shielding is advised. If indeed there is a mass on your breast, next step would be a tissue diagnosis of that lump through a biopsy. It could just be an inflammatory reaction, a simple cyst or other probable breast pathology. youll be guided accordingly by your physician through these steps. The biopsy would tell you the nature of the masslump, and youll be managed accordingly. Hope this helps. Good day!! Chat Doctor. 