Open AccessClinicopathologic and Molecular Characteristics of and Diagnostic Dilemmas in Invasive Breast Carcinoma with Choriocarcinomatous Pattern apropos a New Case: A Literature Review with New Findings
Author(s) -
Sun-Young Jun,
Nara Yoon,
Soyeon An,
Young-Joon Kang,
Chang Suk Park
Publication year - 2022
Publication title -
pathobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 53
eISSN - 1423-0291
pISSN - 1015-2008
DOI - 10.1159/000522621
Subject(s) - medicine , breast carcinoma , carcinoma , pathology , breast cancer , cancer
Background: Invasive breast carcinoma with a choriocarcinomatous pattern (IBC-CP) is extremely rare, and its molecular basis is yet unclear. The choriocarcinomatous pattern is characterized by the biphasic arrangement of multinucleated syncytiotrophoblast-like cells around clusters of monotypic tumor cells in a hemorrhagic background, along with β-human chorionic gonadotropin (β-hCG) expression. The differentiation of IBC-CP from metastatic choriocarcinoma of the breast (MC-B) is difficult due to the histologic similarity. Methods: Based on a literature review and our own case, the clinicopathologic differences between IBC-CP patients ( n = 17) and MC-B patients ( n = 8) were analyzed. Moreover, in our case of IBC-CP, next-generation sequencing (NGS) comparative analysis was conducted for both choriocarcinomatous and invasive breast carcinoma (IBC) components. Results: Compared to the MC-B patients, the IBC-CP patients were older ( p < 0.001) and less frequently had past histories of gestational trophoblastic disease/pregnancy/abortion ( p = 0.001) and distant metastases ( p = 0.005). Our case, a 49-year-old female patient, presented with masses in the right breast and axilla. Following neoadjuvant chemotherapy, a radical mastectomy found an 8.5-cm-sized tumor. Microscopically, multinucleated syncytiotrophoblast-like cells were observed around mononuclear tumor cells with hemorrhage and necrosis. Some tumor cells showed β-hCG immunopositivity, which was compatible with IBC-CP. NGS results showed a missense mutation in exon 5 of the TP53 gene in both the choriocarcinomatous and IBC components. Meanwhile, copy number loss in the PTEN gene was only identified in the choriocarcinomatous components. Conclusion: The present IBC-CP case is triple-negative breast cancer with TP53 mutation. The PTEN gene may be associated with choriocarcinomatous differentiation. Obtaining a medical history is mandatory to exclude metastatic lesions.