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Case Report Volume 17 issue 5
Structural dedifferentiation of breast cancer arising within the major lactiferous ducts: imaging-histopathologic correlation in two fatal cases, part II
László Tabár, Peter B Dean, Miklós Tarján
Received: September 30, 2026 | Published: October 14, 2026
Citation: Tabár L, Dean PB, Tarján M. Structural dedifferentiation of breast cancer arising within the major lactiferous ducts: imaging-histopathologic correlation in two fatal cases, part II. J Cancer Prev Curr Res. 2026;17(4):156-165. DOI: 10.15406/jcpcr.2026.17.00623
Abstract
Background: Breast cancers originating in the epithelia of the major ducts develop through three steps of progression, the 1st being a mammographically occult in situ phase. In the 2nd phase neoducts branch out from the original duct(s) forming an invasive network through the process of neoductgenesis. Neoducts are frequently surrounded by a desmoplastic reaction and lymphocytic infiltration, producing a duct forming invasive carcinoma, termed ductal adenocarcinoma of the breast (DAB). In the 3rd phase defects in the neoduct boundary develop through structural dedifferentiation, allowing the malignant cells to disseminate freely beyond these restrictive neoducts. This 3 rd step is associated with a vastly increased fatality and is termed dedifferentiated ductal adenocarcinoma of the breast (ddDAB). Precis: These case descriptions provide additional, richly illustrated examples of neoductgenesis and structural dedifferentiation of cancers originating within the major lactiferous ducts. The lack of significant progress in reducing the fatality of this group of breast cancers can be attributed to a poor understanding of their complex nature. Case description: Case 1 describes a 48-year-old woman who detected a firm thickening in the upper portion of her left breast five years after her most recent, negative mammograms. Multimodal imaging shows a five cm region having fragmented casting type calcifications associated with a non-specific asymmetric density. Correlation of imaging and large format thin section histopathology demonstrated an extensive malignancy of ductal origin (DAB) associated with multifocal invasive dedifferentiated DAB. Four years after diagnosis and initiation of treatment the patient was diagnosed with distant metastases in the sternum and in the lungs. The distant metastases had histopathologic and immunohistochemical features similar to those of the malignant neoducts (DAB) and dedifferentiated DAB in the breast. Four years and six months after diagnosis and treatment the patient died from metastasizing DAB and ddDAB. Case 2 describes a 52-year-old woman who suffered an unfortunate scenario which is often typical for this breast cancer subtype represented by numerous fragmented type calcifications on the mammogram and by the rapid development of an extensive breast malignancy. The first symptom of this patient was shortness of breath caused by pleural metastases. A search for the primary tumour detected a firm, palpable, diffuse thickening in the upper-outer portion of the right breast. Mammograms showed many fragmented casting type calcifications between the nipple and the chest wall, a characteristic imaging biomarker of breast cancer originating within the major lactiferous ducts. The patient was inoperable, but the microscopic diagnosis was confirmed by 14-G biopsy, which also provided a sufficient amount of tissue to evaluate the IHC biomarkers on both the core biopsy specimen as well as the tissue samples of the pleural metastasis. The patient died from metastasizing dedifferentiated DAB eleven months after diagnosis and initiation of palliative treatment. Conclusion: Current histopathologic terminology and practice considers that the 1 st and 2nd phases in the evolution of breast cancers originating within the major lactiferous ducts are identical by using the same term to describe these two morphologically distinct entities as “DCIS”. This interpretation fails to account for the presence of DCIS-like structures within axillary lymph nodes and in vital organs, or why “microinvasion” is associated with extensive distant metastases and accounts for breast cancer death. The three phases of development proposed by our research group form a fundamental concept supporting efforts to control this aggressive breast malignancy subgroup characterized by fragmented casting type calcifications associated with structural dedifferentiation of neoducts.
Keywords: mammography, breast cancer neoducts, neoductgenesis, dedifferentiation of neoducts, imaging biomarkers
©2026 Tabár, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work non-commercially.