Category Nuances for null:

• solid,
• gastrointestinal,
• neoplastic,
• primary,
• internal,
• underlying,
• malignant,
• common,
• metastatic,
• invasive,
• epithelial,
• intestinal,

Simple Categories for null:

• disease,
• tumor,
• tumour,
• cancer,
• carcinoma,
• malignancy,
• neoplasm,