腫瘍(しゅよう)

A medical term of Sino-Japanese origin, composed of 腫(しゅ) (swelling) + 瘍(よう) (sore, ulcer). Used in clinical and informed health-writing contexts. A casual speaker discussing a lump or bump is more likely to use a vaguer word like しこり (lump) or できもの (growth).

IMPORTANT DISTINCTION — TUMOR VS CANCER:

• 腫瘍(しゅよう): tumor — an abnormal mass of tissue, which may be harmless or dangerous.
• 良性(りょうせい)腫瘍(しゅよう): benign tumor
• 悪性(あくせい)腫瘍(しゅよう): malignant tumor (≈ cancer)
• がん / 癌(がん): cancer — specifically malignant disease. Not every 腫瘍(しゅよう) is がん, but every がん is a 悪性(あくせい)腫瘍(しゅよう).

Common collocations

• 腫瘍(しゅよう)ができる: a tumor forms
• 腫瘍(しゅよう)が見(み)つかる: a tumor is found (passive-feeling)
• 腫瘍(しゅよう)を発見(はっけん)する: to detect / find a tumor
• 腫瘍(しゅよう)を摘出(てきしゅつ)する: to surgically excise a tumor
• 腫瘍(しゅよう)を取(と)り除(のぞ)く: to remove a tumor
• 腫瘍(しゅよう)マーカー: tumor marker

Compounds

• 脳腫瘍(のうしゅよう): brain tumor
• 悪性(あくせい)腫瘍(しゅよう): malignant tumor
• 良性(りょうせい)腫瘍(しゅよう): benign tumor
• 原発(げんぱつ)腫瘍(しゅよう): primary tumor
• 腫瘍(しゅよう)内科(ないか): medical oncology department

Similar words

• しこり: a lump (felt through the skin) — informal and subjective, used before a diagnosis is made.
• できもの: a growth, sore, or skin eruption — vague, includes pimples, cysts, and small tumors.
• 腫(は)れ物(もの): swelling; a lump on or under the skin — slightly more formal than できもの.
• がん / 癌(がん): cancer — a disease category, not a physical object.

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Medical / semi-formal. Appropriate in health articles, doctor-patient conversations, and news. A casual Japanese speaker explaining a non-serious bump would not use 腫瘍(しゅよう) unless they had been told that by a doctor.