Three-dimensional atypical structure in intraductal carcinoma differentiating from papilloma and papillomatosis of the breast

Phase-contrast visualization of human tissues using superimposed wavefront imaging of diffraction-enhanced x-rays

BACKGROUND

Phase-contrast computed tomography (CT) using high-brilliance, synchrotron-generated x-rays enable three-dimensional (3D) visualization of microanatomical structures within biological specimens, offering exceptionally high-contrast images of soft tissues. Traditional methods for phase-contrast CT; however, necessitate a gap between the subject and the x-ray camera, compromising spatial resolution due to penumbral blurring. Our newly developed technique, Superimposed Wavefront Imaging of Diffraction-enhanced x-rays (SWIDeX), leverages a Laue-case Si angle analyzer affixed to a scintillator to convert x-rays to visible light, capturing second-order differential phase contrast images and effectively eliminating the distance to the x-ray camera. This innovation achieves superior spatial resolution over conventional methods.

PURPOSE

In this paper, the imaging principle and CT reconstruction algorithm based on SWIDeX are presented in detail and compared with conventional analyzer-based imaging (ABI). It also shows the physical setup of SWIDeX that provides the resolution preserving second-order differential images for reconstruction. We compare the spatial resolution and the sensitivity of SWIDeX to conventional ABI.

METHODS

To demonstrate high-spatial resolution achievable by SWIDeX, the internal structures of four human tissues-ductal carcinoma in situ, normal stomach, normal pancreas, and intraductal papillary mucinous neoplasm of the pancreas-were visualized using an imaging system configured at the Photon Factory's BL14B beamline under the High Energy Accelerator Research Organization (KEK). Each tissue was thinly sliced after imaging, stained with hematoxylin and eosin (H&E) for conventional microscope-based pathology.

RESULTS

A comparison of SWIDeX-CT and pathological images visually demonstrates the effectiveness of SWIDeX-CT for biological tissue imaging. SWIDeX could generate clearer 3D images than existing analyzer-based phase-contrast methods and accurately delineate tissue structures, as validated against histopathological images.

CONCLUSIONS

SWIDeX can visualize important 3D structures in biological soft tissue with high spatial resolution and can be an important tool for providing information between the disparate scales of clinical and pathological imaging.

A human organoid system that self-organizes to recapitulate growth and differentiation of a benign mammary tumor

As 3D culture has become central to investigation of tissue biology, mammary epithelial organoids have emerged as powerful tools for investigation of epithelial cell polarization and carcinogenesis. However, most current protocols start from single cells suspended in Matrigel, which can also restrict cell differentiation and behavior. Here, we show that the noncancerous mammary cell line HMT-3522 S1, when allowed to spontaneously form cell aggregates ("spheroids") in medium without Matrigel, switches to a collective growth mode that recapitulates many attributes of "usual ductal hyperplasia" (UDH), a common benign mammary lesion. Interestingly, these spheroids undergo a complex maturation process reminiscent of embryonic development: solid-cell cords form their own basement membrane, grow on the surface of initially homogeneous cell aggregates, and form asymmetric lumina lined by two distinct cell types that express basal and luminal cytokeratins. This sequence of events provides a cellular mechanism that explains how the characteristic crescent-shaped, asymmetrical lumina form in UDH. Our results suggest that HMT-3522 S1 spheroids are useful as an in vitro model system to study UDH biology, glandular lumen formation, and stem cell biology of the mammary gland.

Automated reconstruction algorithm for identification of 3D architectures of cribriform ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is a pre-invasive carcinoma of the breast that exhibits several distinct morphologies but the link between morphology and patient outcome is not clear. We hypothesize that different mechanisms of growth may still result in similar 2D morphologies, which may look different in 3D. To elucidate the connection between growth and 3D morphology, we reconstruct the 3D architecture of cribriform DCIS from resected patient material. We produce a fully automated algorithm that aligns, segments, and reconstructs 3D architectures from microscopy images of 2D serial sections from human specimens. The alignment algorithm is based on normalized cross correlation, the segmentation algorithm uses histogram equilization, Otsu's thresholding, and morphology techniques to segment the duct and cribra. The reconstruction method combines these images in 3D. We show that two distinct 3D architectures are indeed found in samples whose 2D histological sections are similarly identified as cribriform DCIS. These differences in architecture support the hypothesis that luminal spaces may form due to different mechanisms, either isolated cell death or merging fronds, leading to the different architectures. We find that out of 15 samples, 6 were found to have 'bubble-like' cribra, 6 were found to have 'tube-like' criba and 3 were 'unknown.' We propose that the 3D architectures found, 'bubbles' and 'tubes', account for some of the heterogeneity of the disease and may be prognostic indicators of different patient outcomes.

A proposal for the histopathological diagnosis of ductal carcinoma in situ of the breast

BACKGROUND

As the incidence of ductal carcinoma in situ (DCIS) is increasing, it is necessary to make a guideline for the pathological examination and diagnosis of DCIS, by creating criteria based on clinical and biological aspects of the disease.

METHOD

We collected biopsy specimens originally diagnosed as benign lesions, from patients who subsequently developed invasive carcinoma in the ipsilateral breast. The histology of the biopsy specimens was re-evaluated principally according to the 1995 Philadelphia Consensus on DCIS. Histopathological agreement on each biopsy specimen was made by the JBCS Study Group members under a multiviewer microscope. In the course of making conclusive agreements among the pathologists, we developed a consensus for the histopathological diagnosis of DCIS, especially non-comedo types.

RESULTS

DCIS is defined as a carcinoma of ductal epithelial origin, without any evidence of stromal invasion. It is necessary to note the methods of pathologic examination required to diagnose DCIS. Stromal invasion is an important prognostic factor, and should be diagnosed with caution. Classification of proliferative ductal lesions as benign or malignant (DCIS), the subtype of DCIS (nuclear grade, architecture, and necrosis), and the histological grading of DCIS are proposed and recommended.

CONCLUSION

Although we have made a new proposal according to current concepts, there are still several unresolved problems. Thus further examination and modification will be necessary in the future.

Pattern of distribution of intraductal and infiltrating ductal carcinoma: a three-dimensional study using serial coronal giant sections of the breast

The purpose of this study was to establish the 3-dimensional (3D) structure of the breast tissue and to study the distribution and relationship between the intraductal and infiltrating components of ductal carcinoma and other proliferative epithelial lesions of the breast. Thirty mastectomy specimens with infiltrating carcinoma less than 3.0 cm in diameter were serially cut in the coronal plane. Each giant section was divided into small sections for routine processing. Using Photoshop (Adobe) and PowerPoint (Microsoft) software programs, the routinely stained sections were scanned and assembled to reestablish complete giant sections of the breast and subsequently the 3D structure. Intraductal and infiltrating ductal carcinomas, epithelial hyperplasia with atypia, and marked epithelial hyperplasia without atypia were mostly confined to a single duct (27 cases), resulting in an increase in size of the involved breast segment. Three remaining cases included a case of Paget's disease with tumor appearing to spread from one duct system to another system through the epidermis and two cases with multiple separate foci of carcinomas located in different quadrants and accompanied by ductal spread in different lactiferous ducts. Both intraductal and infiltrating carcinomas were often located in the superficial segments (near the subcutaneous tissue) (28 cases). The infiltrating components were often located adjacent to area of pure intraductal carcinoma and were often peripheral (nearer the chest wall than the nipple). Intraductal carcinomas showed a "fanned out" pattern of distribution, frequently extended toward the nipple (with involvement of the nipple or subareolar tissue in 7 cases), and occasionally were seen in the breast tissue peripheral to the infiltrating carcinoma. Multiple ducts with intraductal carcinoma could be seen to be connected with each other with serial sections. However, in at least 6 cases, foci of intraductal carcinomas were separated from each other by segments of duct with benign epithelium. Breast carcinoma often arise from the breast segment close to the subcutaneous tissue. Infiltrating carcinoma lesser than 3.0 cm in diameter is usually located adjacent to the area of pure intraductal. The pattern of spread of intraductal carcinoma has a pyramid-like shape, with the summit toward and occasionally extending up to the nipple. These findings should be considered in the surgical strategy for segmental resections of breast carcinomas.

Breast-conserving surgery for invasive cancer: a principle based on segmental anatomy

As the incidence of breast cancer increases in Japan, breast-conserving surgery becomes an important issue in the light of quality of life. We have demonstrated by 3-D reconstruction studies that ductal carcinoma in situ (DCIS) originates from the terminal duct-lobular unit (TDLU). Normal mammary epithelium anatomically located in the TDLU was shown to be biologically associated with cancerous change, particularly in specimens from patients who subsequently developed invasive carcinoma. Atypical ductal hyperplasia as well as DCIS expressed breast cancer associated antigen, providing further biological evidence that the atypical lesion at the TDLU are premalignant. Intraductal spread of carcinoma was defined as "DCIS was present clearly extending beyond the TDLU, or present prominently within the large ducts," and was classified into 3 grades according to the distribution of carcinoma in the duct-lobular system. We have developed a breast-conserving surgery consisting of quadrantectomy and regional lymph node dissection and immediate volume replacement using lateral tissue-flap (LTF). The quadrantectomy was employed on the basis of segmental anatomy of the duct-lobular system in which breast carcinoma originates. Fairly good cosmetic outcome as well as local control were obtained in the patients who underwent the immediate volume replacement using LTF. It must be emphasized that the quadrantectomy is a radical procedure in the sense that it aims at removal of all the carcinoma cells of the primary tumor.

Management of ductal carcinoma in situ with nipple discharge. Intraductal spreading of carcinoma is an unfavorable pathologic factor for breast-conserving surgery

BACKGROUND

Surgical management of ductal carcinoma in situ (DCIS) has been a controversial issue in the selection of breast-conserving surgery as a method of treatment. The definition of intraductal spreading of carcinoma becomes an important factor in the decision making process, but little is known about how much intraductal extension influences the spreading of tumor in the whole breast. To define any unfavorable pathologic factors existing in limited surgery for patients with DCIS, the authors investigated histopathologic characteristics using a sequential slicing of tissues.

METHODS

Duct-lobular segmentectomy, a limited surgery, was performed on 110 patients with a bloody nipple discharge. Six patients with invasive carcinoma and 17 patients with DCIS subsequently received a total mastectomy. The specimens obtained by segmentectomy and mastectomy were histopathologically examined. Using subserial sections, the authors examined the relationship between intraductal spreading of carcinoma in the segmentectomy specimens and carcinoma residue in the mastectomy specimens.

RESULTS

Among 16 mastectomy specimens, the authors found residual DCIS in 6, and atypical ductal hyperplasia in 4. Intraductal spreading of carcinoma was detected in 8 of 16 segmentectomy specimens. Six of eight patients with intraductal spreading had residual DCIS. The other two patients had atypical hyperplasia in breasts. No residual DCIS was detected in the other eight patients without intraductal spreading. Among 12 patients under observation who did not have a mastectomy, invasive carcinoma subsequently developed in 3. Two of three patients had intraductal spreading in segmentectomy specimens. Only 1 of 10 patients without intraductal spreading, however, developed carcinoma.

CONCLUSIONS

Intraductal spreading of carcinoma is an unfavorable pathologic factor in breast-conserving surgery for patients with ductal carcinoma in situ with nipple discharge.

An original stereomicroscopic analysis of the mammary glandular tree

In the 1970s, Wellings developed and reported extensively on a technique for a three-dimensional (3D) analysis of breast lesions. Drawbacks of this subgross sampling technique were that it was laborious, rather time-consuming and only allowed prospective studies. Furthermore, the stereomicroscopic aspect of the lesions studied was not diagnostic and each sample had to be studied histologically after paraffin embedding to determine the diagnosis. The present study introduces an original method enabling the exploration of the 3D structure of the mammary glandular tree from a paraffin-embedded sample. This procedure is quicker than the Wellings' technique, permits retrospective study and enables a 3D analysis of previously identified histological structures. Stereomicroscopic aspects of non-malignant lesions such as single multiple or metaplastic cysts, adenosis, ductal-lobular hyperplasia and malignant in situ neoplasms are illustrated. Our results confirm Wellings' concept that most minimal lesions arise in the terminal ductulo-lobular units. We also show that ductal carcinoma in situ may grow continuously by extending through the glandular tree but may also have a multifocal or stepwise progression in some cases.

Anatomic markers of human premalignancy and risk of breast cancer

Epithelial hyperplasia of the breast carries an increased likelihood of carcinoma development, with most lesions best understood as markers of higher risk. The indication of increased cancer risk for more worrisome or complex histologic patterns has been supported in many studies. About 25% of women who underwent biopsies in the premammographic era had well-developed hyperplastic changes associated with an elevated risk of 1.5 to 2.0 times that of the general population when age and length of time of follow-up were considered. Somewhat fewer than 5% of women had specific patterns of atypical hyperplasia (AH) that approached the criteria of carcinoma in situ (CIS). These women with AH had a risk of cancer four to five times that of the general population, or about one half the risk associated with microscopic CIS. Only ductal CIS should be considered without question to be an intrinsic precancerous lesion because of its regular association with recurrence at the site of its initial diagnosis. Further studies indicated an appreciable interaction between AH and other nonanatomic risk factors, particularly a family history of breast cancer. Also, lower dosage estrogen replacement after menopause does not affect risk in any histologically defined group. The atypical hyperplastic lesions are more common in women undergoing biopsies on the indication of mammographic calcifications than because of palpable masses. The primary therapeutic implications of these premalignant lesions are intensified breast cancer surveillance and screening for these patients.

Premalignant conditions and markers of elevated risk in the breast and their management

Most epithelial hyperplasias of the human breast indicate an increased likelihood of carcinoma development, and the majority are best understood as markers or indicators of higher risk. Prospective studies of women with hyperplasia biopsied in the premammographic era indicate that about 70 per cent of women had mild or no hyperplastic epithelial alterations and experienced no increase in the risk of subsequent carcinoma. About 25 per cent of women had well-developed hyperplastic changes associated with a risk 1.5 to 2.0 times that of the general population controlled for age and length of follow-up. Somewhat fewer than 5 per cent of women had specific patterns of atypical hyperplasia that approached the patterns of carcinoma in situ. The women with atypical hyperplasia had a risk of cancer four to five times that of the general population, or about half the risk associated with microscopic carcinoma in situ. Only ductal carcinoma in situ should be considered without question to be an intrinsically precancerous lesion because of its regular association with recurrence at the site of its initial diagnosis. No follow-up studies of comparable type involving women with mammographically detected lesions are as yet available. However, it is clear that the incidence of atypical hyperplasia is higher in mammographically directed biopsies. The principal therapeutic implication of these premalignant lesions is a need for intensified breast cancer surveillance and screening for these patients.