What happened, in summary

A 75-year-old woman had advanced gastric adenocarcinoma. Surgeons attempted a gastrectomy but could not remove the tumor because it involved the pancreatic head and nearby lymph nodes. She instead underwent a palliative gastric bypass and was considered too frail for chemotherapy.

One month later, she arrived at the emergency department with a painful, tense swelling of the right thumb. Two courses of antibiotics had already been given for a presumed soft-tissue infection after a minor burn, but the swelling continued. Examination showed marked tenderness and loss of movement at the thumb joint. Imaging and tissue examination established that the lesion involved the distal phalanx and represented metastatic gastric adenocarcinoma rather than infection.

Her case was reviewed by the upper gastrointestinal multidisciplinary team. Because the gastric cancer was advanced and treatment goals were palliative, radiotherapy to the thumb was offered to reduce pain and preserve function. The case illustrates how bone metastases in the hand can resemble infection and may be overlooked, especially when swelling follows a minor injury.