A woman was not told she had cancer until the week before she died, despite having been diagnosed three months earlier.
Beverley Smith, 63, from Truro, Cornwall died in July.
The results of a biopsy taken in Plymouth in March were not shared with her, or with medics treating her at hospital in Truro.
Derriford and the Royal Cornwall Hospitals said the care she received was “below the trust’s expectations”.
For six years, Ben Smith was a full-time carer for his mother, who had been paralysed from the chest down since a road accident in 1972.
He said: “If we’d known she had cancer she could have come home for three months and we could have had that time together.”