Correlation Analysis of Digital Mammography, Ultrasonography, and Pathologic Features in Pure Invasive Micropapillary Carcinoma of the Breast (PIMPC).

Purpose: This study determined the digital mammography and ultrasonography imaging features of pure invasive micropapillary carcinoma of the breast (PIMPC) and the correlation with pathologic features. Patients Methods: Nineteen patients diagnosed with PIMPC at Yantaishan Hospital from October 2015 to February 2022 were included in the study group. Forty patients with breast masses diagnosed as nonspecific invasive ductal carcinoma of the breast (NIDC) from July to December 2021 were included in the control group. Digital mammography and ultrasonography features were compared between the two groups. Results: Patients with PIMPC had a younger age profile compared to patients with NIDC (P=0.017). Moreover, PIMPC masses were smaller than NIDC masses (P=0.040). Imaging features analysis revealed significant differences in age groups (<45 years: χ²=5.971, P=0.044) and the presence of spiculations or the crab claw sign (χ²=8.583, P=0.004) between patients with PIMPC and NIDC. However, there were no statistically significant differences in the presence of calcifications, blood flow grading, pathologic molecular subtypes between the study and control groups. The Ki-67 proliferative index (χ²=1.052, P=0.389), vascular invasion (χ²=2.263, P=0.197), and lymph node metastasis (χ²=1.968, P=0.386) showed no significant differences between PIMPC and NIDC patients. Conclusion: PIMPC imaging features show specificity, such as tiny breast masses, spiculated edges, or crab claw-like patterns, and malignant signs appeared when the lesion was <2 cm in diameter. PIMPC mainly occurs in middle-aged women 45-59 y of age. Patients with PIMPC and NIDC of the breast are frequently associated with lymph node metastases and greater than one-half of the cases (74%) were shown to have a Ki-67 index >30%, suggesting a significant risk of recurrence and metastasis. Early therapeutic care for these patients is crucial. These results warrant further validation with additional samples from several centers due to the limited single-center sample size in the current study.

Carcinoma micropapilar infiltrante de la mama. Pronóstico a largo plazo / Invasive micropapillary carcinoma of the breast. Long term outcome

Introducción: el carcinoma micropapilar infiltrante (CMI) es una variante histológica inusual y potencialmente agresiva caracterizada por primera vez en 1993 por Siriangkul et al. y que no formó parte de la clasificación de la Organización Mundial de la Salud (OMS) hasta 2003, como tumor mamario epitelial. Representa menos del 2% del total de carcinomas invasivos de la mama y se presupone que presenta un pronóstico desfavorable en comparación con otros carcinomas convencionales debido a su elevado tropismo vascular y linfático. Material y métodos: hasta la fecha no existe ningún estudio con un número elevado de pacientes procedentes de un único centro (> 100 casos) con un periodo de seguimiento largo (> 20 años) que compare la supervivencia del CMI con otros carcinomas convencionales no micropapilares. Se ha llevado a cabo un estudio retrospectivo, observacional con un total de 401 pacientes: 174 con CMI y 227 con otros carcinomas convencionales. Resultados: el CMI presenta mayor grado histológico, mayor afectación ganglionar y mayor riesgo de metástasis a distancia en comparación con otros carcinomas convencionales de características similares. Sin embargo, en el análisis multivariante considerando factores pronósticos como edad, tamaño tumoral, afectación ganglionar y grado histológico, no se observan diferencias estadísticamente significativas para la supervivencia global y libre de enfermedad entre los CMI diagnosticados en el mismo periodo de tiempo que los casos pareados del grupo control y otros carcinomas convencionales. Conclusión: la supervivencia global y libre de enfermedad es similar entre el CMI y otros carcinomas convencionales a igual edad, tamaño tumoral, grado histológico y afectación ganglionar. (AU)

Introduction: Invasive Micropapillary Carcinoma of the breast (IMPC) is an unusual and aggressive histological variant characterized for the first time in 1993 by Siriangkul et al. and classified by the World Health Organization in 2003 as an epithelial breast tumor. It represents less than 2% of all invasive carcinomas of the breast and is presumed to have an unfavorable prognosis compared to other conventional carcinomas due to its high vascular and lymphatic tropism. Material and methods: Until now, there is no study with a large number of patients from a single center with a long follow-up period that compares the survival of IMPC with other conventional non-micropapillary carcinomas. A retrospective, observational study has been carried out with a total of 401 patients: 174 with IMPC and 227 with other conventional carcinomas. Results: IMPC has a higher histological grade, greater lymph node involvement and a higher risk of distant metastasis compared to other conventional carcinomas. However, in the multivariate analysis considering date of diagnosis, age, tumor size, lymph node involvement and histological grade as variables, no statistically significant differences were observed for overall and disease- free survival between IMPC and other conventional carcinomas. Conclusion: Overall and disease-free survival is similar between IMPC and other conventional carcinomas considering same age, tumor size, histological grade, and lymph node involvement. (AU)

Authentication of a survival nomogram for non-invasive micropapillary breast cancer.

Purpose: We aimed at establishing a nomogram to accurately predict the overall survival (OS) of non-metastatic invasive micropapillary breast carcinoma (IMPC). Methods: In the training cohort, data from 429 patients with non-metastatic IMPC were obtained through the Surveillance, Epidemiology, and End Results (SEER) database. Other 102 patients were enrolled at the Xijing Hospital as validation cohort. Independent risk factors affecting OS were ascertained using univariate and multivariate Cox regression. A nomogram was established to predict OS at 3, 5 and 8 years. The concordance index (C-index), the area under a receiver operating characteristic (ROC) curve and calibration curves were utilized to assess calibration, discrimination and predictive accuracy. Finally, the nomogram was utilized to stratify the risk. The OS between groups was compared through Kaplan-Meier survival curves. Results: The multivariate analyses revealed that race (p = 0.047), surgery (p = 0.003), positive lymph nodes (p = 0.027), T stage (p = 0.045) and estrogen receptors (p = 0.019) were independent prognostic risk factors. The C-index was 0.766 (95% CI, 0.682-0.850) in the training cohort and 0.694 (95% CI, 0.527-0.861) in the validation cohort. Furthermore, the predicted OS was consistent with actual observation. The AUCs for OS at 3, 5 and 8 years were 0.786 (95% CI: 0.656-0.916), 0.791 (95% CI: 0.669-0.912), and 0.774 (95% CI: 0.688-0.860) in the training cohort, respectively. The area under the curves (AUCs) for OS at 3, 5 and 8 years were 0.653 (95% CI: 0.498-0.808), 0.683 (95% CI: 0.546-0.820), and 0.716 (95% CI: 0.595-0.836) in the validation cohort, respectively. The Kaplan-Meier survival curves revealed a significant different OS between groups in both cohorts (p<0.001). Conclusion: Our novel prognostic nomogram for non-metastatic IMPC patients achieved a good level of accuracy in both cohorts and could be used to optimize the treatment based on the individual risk factors.

Invasive micropapillary breast carcinoma: A retrospective study on the clinical imaging features and pathologic findings.

Purpose: To describe the clinical imaging and pathological features of invasive micropapillary breast carcinoma (IMPC), including breast mammography, sonography, magnetic resonance imaging (MRI), and molecular imaging findings. Patients and methods: We retrospectively reviewed our institution's surgical pathology database and identified 65 patients with pathologically proven IMBC; 63/65 patients had available imaging results. Two radiologists retrospectively reviewed all imaging evaluations according to the Breast Imaging Reporting / Data System (BI-RADS) Lexicon. Clinical and histopathologic features, receptor statuses, and clinical follow-up data were recorded. Results: Sixty-three patients were admitted with palpable abnormalities; one patient's mammogram revealed no abnormality (3.3%, 1/32), whereas 31 had abnormal mammograms (31/32, 96.8%) demonstrating 37 lesions. Twenty-four had irregular, spiculated masses, 12 had microcalcifications, and 19 had architectural distortion. Sonography detected 69 masses (54 patients), characterized by irregular shapes (61/69, 88.4%), hypoechoic structures (50/69, 72.4%), angular or spiculated margins (38/69, 55.1%; 30/69, 43.4%), echogenic halo (8/69, 11.5%), and abnormal vascularity (52/69, 75.3%). MRI detected 68 lesions (52 patients); 59/68 (86.8%) appeared as masses with angular or spiculated margins (32/68, 47.1%; 35/68, 51.4%), 58 exhibited irregular or lobulated shapes (58/68, 89.7%), 29 displayed heterogeneous internal enhancement (29/68, 42.5%), and 64 demonstrated type II or III washout kinetic curves (37/68, 55%; 27/68, 40%). Breast molecular imaging showed mild-to-moderate radiotracer uptake in 15 focal areas among 13 patients. Thirty-two, 38, and 43 patients had abnormal lymph nodes identified mammographically, by breast sonography, and by MRI, respectively. Immunohistochemistry revealed high estrogen receptor (90.5%), high progesterone receptor (71.6%), and low HER-2 (26.4%) positivity. Conclusion: IMPC mammography, sonography, and MRI clinical imaging features highly suggest malignancy. Breast molecular imaging also contributed to the diagnosis. IMPC's invasiveness correlated well with regional lymph node metastasis. Radiologists and surgeons should be more attentive to these imaging findings and additional clinical and pathological IMPC features.