In my opinion, the invasive pattern with isolated cells and irregular glands in stroma, fibrotic background, and the degree of cytologic atypia are sufficient for a malignant diagnosis.

• 翻译：依我的意见，间质中可见孤立的细胞和不规则的腺体是浸润的特征，纤维化背景，一定程度的细胞异型性足以诊断恶性。