Hi! thanks for writing to HCM sharing your health problem!
Well, it is very common in our clinic to get such lumps which are painless, hard and increasing in size and therefore, I would like to consider few possibilities in your case of the lump between collar bone and shoulder blade as follows:
1. a sebaceous cyst or ganglion or some other
benign cyst 30% possibility
2.
benign skin tumor or tumor-like conditions like lipoma,
dermatofibroma or
neurofibroma 30% possibility
3.
soft tissue tumor or tumor like conditions 20% possibility
4. lymph nodes , benign 10% possibility
5. lymph node infective 5% possibility
6. lymph node, malignant like lymphoma or cancer 3% possibility
7. other neoplastic or cancerous conditions 2% possibility
Therefore ultrasound can assist you in the diagnosis but only a needle biopsy could confirm it!
Regards,