necrotic lymph node enlargement may be due to multiple causes, but you need to get proper diagnosis as they are highly suggestive of cancer , but there may be other aetiologies eg infectious (abdominal tb) etc so get proper assessment by a surgeon as more information is required eg your symptoms your general physical condition any fever associated any history of bleeding etc
Next Steps
visit a surgeon as physical examination will also be required to reach a proper diagnosis
Health Tips
do not delay.
you can always consult on practo for second opinion or explanations.