Prediction of the Nottingham prognostic index and molecular subtypes of breast cancer through multimodal magnetic resonance imaging.

PURPOSE: To explore the ability of intravoxel incoherent motion (IVIM), diffusion kurtosis imaging (DKI) and background parenchyma enhancement (BPE) to predict the Nottingham prognostic index (NPI) and molecular subtypes of breast cancer (BC). MATERIALS AND METHODS: In this study, 93 patients with BC were included, and they all underwent DKI, IVIM and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) examinations. The corresponding mean kurtosis value (MK), pure diffusion (MD), perfusion fraction (f), pseudo diffusion coefficient (D*), true diffusion coefficient (D), and BPE were measured. We used logistic regression analysis to investigate the relevance between the NPI, molecular subtypes and variables. The diagnostic efficacy was analyzed using receiver operating characteristic curves (ROC). RESULTS: The MD and D values of the high-level NPI group were significantly lower than those of the low-level NPI group (p < 0.01), and the f value of the high-level NPI group was obviously higher than that of low-level NPI group (p < 0.001). The area under curve (AUC) of the combined model (f + D) was 0.824. Comparing with non-Luminal subtypes, the Luminal subtypes showed obviously lower MK, f and D*, and the AUC of the combined model (MK + f + D*) was 0.785. In comparison to other subtypes, the MK and D* values of triple-negative subtype were higher than other subtypes, and the combined model (MK + D*) represented an AUC of 0.865. CONCLUSION: The quantitative parameters of DKI and IVIM have vital value in predicting the NPI and molecular subtypes of BC, while BPE could not provide additional information. Besides, these combined models can obviously improve the prediction performance.

A Rare Case of Breast fat-Forming Solitary Fibrous Tumor With Molecular Confirmation.

Solitary fibrous tumor (SFT) is an uncommon fibroblastic neoplasm which may arise in a wide range of anatomic location and can occur across all ages. Fat-forming SFT is a rare morphological variant of SFT. Primary breast fat-forming SFT is exquisitely rare. Here, we report a case in a 51-year-old Chinese woman with a palpable painless mass in the left breast. A color Doppler ultrasound scan examination demonstrated a 3.4-cm oval, well-circumscribed, hypoechoic solid mass with several peripheral and internal color flow signals. Magnetic resonance imaging (MRI) showed a focal lobulated solid nodular lesion displaying geographical enhancement but no architectural distortion. Subsequently, she underwent a left breast lumpectomy. In histopathologic examination, there was a well-circumscribed, cellular spindle cell tumor consisting of short fascicles of bland, fusiform, ovoid to spindle cells disposed in a patternless architecture around branching vascular spaces within a fibrous stroma with wispy collagen. Cells revealed mild nuclear atypia. Mitotic figures were up to 4/10 high-power fields (HPFs) in the hot spot. Mature adipocytes intermixed with spindle cells were also observed. The tumor cells were diffusely positive for CD34 and STAT6. Some S100-expressing adipocytes co-expressed STAT6. Next-generation sequencing (NGS) revealed the presence of the NAB2exon6::STAT6exon2 fusion. The histological, immunohistochemical (IHC) and molecular examinations confirmed the diagnosis of fat-forming SFT. Post-excision, the patient showed no signs of tumor recurrence or metastasis in a 7-month follow-up. Here, we describe a rare case of a fat-forming SFT involving the breast and highlight the comprehensive pathological evaluation and necessary ancillary testing.