Mixed neuroendocrine and endometrioid carcinoma of the endometrium: a rare aggressive malignancy

• Published in: International journal of gynecological cancer Vol. 34; no. 11; p. 1828
• Main Authors: Bakshi, Neha, Modi, Rahul D, Srivastava, Mala, Badwal, Sonia
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 04.11.2024
• Subjects: Cancer; Cytokeratin; Cytoplasm; Editing; Endometrial cancer; Endometrium; Estrogens; Females; Medical prognosis; Metastasis; Morphology; Pathology; Proteins; Tumors; Neuroendocrine Tumors; Endometrial Neoplasms
• DOI: 10.1136/ijgc-2023-004929
• ISSN: 1048-891X

Correspondence to Dr Sonia Badwal, Pathology (Histopathology division), Sir Ganga Ram Hospital, New Delhi, Delhi, 110060, India; soniabadwal06@gmail.com Uterine neuroendocrine carcinomas are rare, accounting for <1% of endometrial carcinomas, and include both large cell and small cell types.1 Prognosis is distinctly worse, even in early stage tumors, with strong propensity for rapid recurrence and distant metastasis.2 3 Accurate diagnosis is therefore crucial to improve patient survival. According to the World Health Organization (WHO) 2020 classification, diagnosis of large cell neuroendocrine carcinoma requires a combination of this high grade neuroendocrine histomorphology and expression of at least one neuroendocrine marker (synaptophysin, chromogranin, or CD56) in >10% tumor cells.2 3 Chromogranin positivity is more specific, as synaptophysin expression is reported in both endometrioid (21%) and serous (13%) endometrial carcinomas, while CD56 can stain endometrioid endometrial and ovarian carcinomas.2 INSM1 is a novel immunohistochemistry marker, with superior performance to conventional neuroendocrine markers in cervical tumors.4 Cytokeratin is usually positive, but rare cytokeratin negative cases are documented in the literature.2 Up to two thirds of neuroendocrine carcinomas are negative for PAX8, and these tumors may be associated with microsatellite instability (up to 44% of cases).2 Uterine neuroendocrine carcinomas may be histologically pure, but are frequently (50–80%) admixed with non-neuroendocrine carcinoma (endometrioid >serous) components, and such cases are classified by WHO as combined or mixed neuroendocrine carcinomas. Twitter @, @ModiRahul86 Contributors NB: design, literature search, data acquisition, data analysis, manuscript preparation, and manuscript editing.