Can you detect a sebaceous cyst under ultrasound? my doc said its a sebaceous cyst but i think its a swollen lymph node.

Sebaceous cyst: It all depends on where the "cyst" is. If it is on the back, buttocks, abdominal wall, chest or neck it is most likely a sebaceous cyst. If it is in the armpit or groin it could also be an enlarged lymph node. An ultrasound examination can certainly distinguish between an enlarged lymph node and a sebaceous cyst. See your internist if the lump does not resolve.

Cystic lesions: Ultrasound is good for distinguishing solid vs. cystic lesions and measuring depth. The juncture between tissues like fat and dermis can also often be identified. So if the lesion had cystic characteristics AND was within or attached to the skin, he has made a reasonable diagnosis. Some larger skin lesions can feel quite deep and be mistaken by palpation for other lesions. Path exam wld b good .