Department of Pathology, Massachusetts General Hospital, 55 Fruit Street, 02114, Boston, MA, USA.
Harvard Medical School, Boston, MA, USA.
Diagn Pathol. 2024 Sep 12;19(1):123. doi: 10.1186/s13000-024-01546-6.
Grade 3 neuroendocrine tumor (G3 PanNET) and poorly differentiated neuroendocrine carcinoma (PanNEC) of the pancreas are considered distinct entities from a biological and prognostic perspective but may have overlapping features complicating a definitive diagnosis.
A 52-year-old female presented with a pancreatic body mass and liver lesions. Initial biopsies showed variable lower- and higher-grade morphologies and modestly elevated Ki67 proliferation index up to 30%, leading to a diagnosis of G3 PanNET. The patient underwent everolimus treatment followed by surgical resection, revealing a complex tumor with features of both G3 PanNET and PanNEC, including admixed well- and poorly differentiated morphologies, modestly elevated hotspot Ki67 of 28%, retained ATRX/DAXX expression, and loss of RB expression. The final diagnosis rendered was "high-grade neuroendocrine neoplasm" with discussion of both entities in the differential. Post-operatively, the patient remains alive with stable metastases.
This case highlights the diagnostic complexities of distinguishing G3 PanNET and PanNEC even with the support of ancillary immunohistochemical and molecular studies. In addition, such cases raise the possibility that G3 PanNET and PanNEC may lie on a spectrum of disease with potential biological overlap.
3 级神经内分泌肿瘤（G3 胰腺神经内分泌肿瘤）和分化差的胰腺神经内分泌癌（PanNEC）从生物学和预后的角度来看被认为是不同的实体，但可能具有重叠的特征，使明确诊断变得复杂。
一名 52 岁女性因胰腺体肿块和肝脏病变就诊。初始活检显示形态学存在可变的低级别和高级别，Ki67 增殖指数适度升高至 30%，导致 G3 胰腺神经内分泌肿瘤的诊断。患者接受了依维莫司治疗，随后进行了手术切除，发现肿瘤具有 G3 胰腺神经内分泌肿瘤和 PanNEC 的特征，包括混合的良好和低度分化形态学，适度升高的热点 Ki67 为 28%，保留 ATRX/DAXX 表达，以及 RB 表达缺失。最终诊断为“高级别神经内分泌肿瘤”，并在鉴别诊断中讨论了这两种肿瘤。术后，患者仍存活且转移稳定。
即使有辅助免疫组织化学和分子研究的支持，本病例也强调了区分 G3 胰腺神经内分泌肿瘤和 PanNEC 的诊断复杂性。此外，此类病例提出了 G3 胰腺神经内分泌肿瘤和 PanNEC 可能处于疾病谱上的可能性，存在潜在的生物学重叠。
