Had 3 drs look at invisible lump, no biop. decided its deep lipoma partly on spine. i found almost matching pair below ribs. spot on back liposarcoma?

Likely not: Liposarcomas are very rare, but you can't say one is present or not except after a biopsy.

Probably not: Most subcutaneous above muscle fascia tumors are lipomas. Common to have multiple lipomas at the same time. The lipoma is soft compared to liposarcoma which is firm. Soft fatty tumors under 10 cm. in size are for the most part benign. The growing lipoma which becomes firm is usually the Sa. In very large lipomas, one can find variations with lipoma and Sa mixed in the same growth.