良性

• Reading: りょうせい
• Romaji: ryousei
• Kanji breakdown: 良 (ryou) — good, fine; 性 (sei) — nature, character, type
• Pronunciation: /ɾjoː.seː/

Meaning

Benign. Describes a tumour or growth that is not cancerous and does not spread to other parts of the body. Also means good-natured or mild in character.

A na-adjective and noun used primarily in oncology to contrast with 悪性 (malignant). 良性腫瘍 (benign tumour) does not invade surrounding tissue or metastasise, though it may still require monitoring or removal. In non-medical usage, 良性 can describe a person's kind disposition or a mild version of a phenomenon, as in 良性の競争 (healthy competition).

Examples

1. 腫瘍の生検の結果、良性であることが確認され家族は安堵した。 The biopsy results confirmed that the tumor was benign, and the family was relieved.
2. 良性の腫瘍であっても、大きくなれば手術での摘出が必要になることもある。 Even a benign tumor may require surgical removal if it grows large enough.
3. 医師から良性と診断されても、定期的な経過観察は欠かせない。 Even after being diagnosed as benign, regular follow-up monitoring is essential.

Usage Guide

Context: medicine, oncology, diagnosis, surgery, pathology

Tone: clinical, reassuring

Origin & History

Sino-Japanese compound: 良 (ryou) means good, fine, or excellent, and 性 (sei) means nature, character, or type. Used in contrast with 悪性 (malignant, literally bad-natured). The medical usage mirrors the classical Chinese binary of good/bad nature applied to disease.

Cultural Context

Era: Modern

Generation: Adult

Social background: Universal