Using immunohistochemistry to classify the molecular subtypes of Paget's disease of the breast.

PURPOSE: To classify the molecular subtypes of Paget's disease of the breast, and then compare them with general breast cancer to get deeper understanding of this disease and offer better management of associate patients in clinical decisions. METHODS: We used immunohistochemistry to examine 42 cases of this disease by antibodies against estrogen and progesterone receptors, Ki-67, as well as human epidermal growth factor receptor 2 (HER-2). Due to damage and loss of specimens, etc., we obtained 36 pathological specimens from the 42 patients. For 30 of 36 pathological specimens (83.3%), we obtained a complete molecular subtype. Cause the other 6 pathological specimens have missing immunohistochemistry items. For patients with bilateral breast cancer, only information on the side with PDB is listed. For patients with recurrence, only information on the first onset was included. We finally compared and studied the molecular subtype of 26 samples. We calculated the relative frequencies of molecular subtypes including luminal A, luminal B, HER-2-enriched, and basal-like and compared them between PDB and general breast carcinomas in other studies. RESULTS: The luminal A and B subtype were found, respectively, in 3 (11.5%) and 6 (23.1%) of all patients, and 15 cases of HER-2-enriched subtype was detected (57.7%). In addition, 2 (7.7%) showed a basal-like subtype. CONCLUSION: The molecular subtypes of common breast cancer and PDB-associated breast cancer differ. Luminal subtypes are the most common in the former, while within our samples HER-2 positive subtype was the highest in PDB-associated breast carcinoma. With further understanding of this disease, rational therapies will be applied in different patients and cures for PDB and PDB-associated carcinoma will be achieved.

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.