1.
an abnormal mass of tissue in the body; a tumor
The standard medical term for a tumor — an abnormal growth of tissue that can be either benign or malignant. Used in clinical writing, patient explanations, and news reports on health. Not the same as "cancer" — a tumor may or may not be cancerous.
腫瘍が見つかった。
A tumor was found.
検査の結果、良性の腫瘍だと分かった。
The tests showed that it was a benign tumor.
医師は腫瘍を手術で取り除くことを勧めた。
The doctor recommended surgically removing the tumor.
定期検診で早期に腫瘍を発見することが、治療の成功率を大幅に高める。
Detecting tumors early through regular checkups significantly raises the success rate of treatment.
A medical term of Sino-Japanese origin, composed of 腫 (swelling) + 瘍 (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: tumor — an abnormal mass of tissue, which may be harmless or dangerous.
- 良性腫瘍: benign tumor
- 悪性腫瘍: malignant tumor (≈ cancer)
- がん / 癌: cancer — specifically malignant disease. Not every 腫瘍 is がん, but every がん is a 悪性腫瘍.
COMMON COLLOCATIONS:
- 腫瘍ができる: a tumor forms
- 腫瘍が見つかる: a tumor is found (passive-feeling)
- 腫瘍を発見する: to detect / find a tumor
- 腫瘍を摘出する: to surgically excise a tumor
- 腫瘍を取り除く: to remove a tumor
- 腫瘍マーカー: tumor marker
COMMON COMPOUNDS:
- 脳腫瘍: brain tumor
- 悪性腫瘍: malignant tumor
- 良性腫瘍: benign tumor
- 原発腫瘍: primary tumor
- 腫瘍内科: 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.
- 腫れ物: swelling; a lump on or under the skin — slightly more formal than できもの.
- がん / 癌: cancer — a disease category, not a physical object.
REGISTER:
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 unless they had been told that by a doctor.