Radiologic-pathologic Correlation Research Articles

Artificial Intelligence in Radiology Education: A Longitudinal Approach

Artificial intelligence (AI) and machine learning (ML) techniques stand poised to redefine the face of radiology. Far from mere technological novelty, AI products have received U.S. Food and Drug Administration (FDA) authorizations in increasing numbers (1) with applications spanning the gamut from image interpretation and protocoling to physician workflow management and radiologic-pathologic correlation (2). AI may represent the future of radiology, but no commensurate training pathway for radiologists is currently available.

MR Imaging of uterine sarcomas: a comprehensive review with radiologic-pathologic correlation.

The aim of this article is to summarize the MRI features of each sarcoma subtype and to correlate them with its pathological findings. Literature review through PubMed/Medline database to identify relevant articles on uterine sarcomas, with a special emphasis on their MRI findings and pathological features. While several, more generalistic, MRI findings of a uterine tumour should raise suspicion for malignancy (including irregular contour, intra-tumoral necrosis/hemorrhage and low ADC values), some particular features may suggest their specific histological subtype such as the gross lymphovascular invasion associated with endometrial stromal sarcomas, the "bag of worms" appearance of the low-grade endometrial stromal sarcoma and the "lattice-like" aspect of adenosarcomas which results from the mixed composition of solid and multiseptated cystic components. Knowledge of the different histological uterine sarcoma subtypes, their specific MRI features and comprehension of their pathological background allows for a more confident diagnosis and may indicate the correct histological subtype.

Approach to Cystic Lesions in the Abdomen and Pelvis, with Radiologic-Pathologic Correlation

Cystic lesions found in and around the peritoneal cavity can often be challenging to diagnose owing to significant overlap in imaging appearance between the different entities. When the cystic lesion can be recognized to arise from one of the solid abdominal organs, the differential considerations can be more straightforward; however, many cystic lesions, particularly when large, cannot be clearly associated with one of the solid organs. Cystic lesions arising from the mesentery and peritoneum are less commonly encountered and can be caused by relatively rare entities or by a variant appearance of less-rare entities. The authors provide an overview of the classification of cystic and cystic-appearing lesions and the basic imaging principles in evaluating them, followed by a summary of the clinical, radiologic, and pathologic features of various cystic and cystic-appearing lesions found in and around the peritoneal cavity, organized by site of origin. Emphasis is given to lesions arising from the mesentery, peritoneum, or gastrointestinal tract. Cystic lesions arising from the liver, spleen, gallbladder, pancreas, urachus, adnexa, or soft tissue are briefly discussed and illustrated with cases to demonstrate the overlap in imaging appearance with mesenteric and peritoneal cystic lesions. When approaching a cystic lesion, the key imaging features to assess include cyst content, locularity, wall thickness, and presence of internal septa, solid components, calcifications, or any associated enhancement. While definitive diagnosis is not always possible with imaging, careful assessment of the imaging appearance, location, and relationship to adjacent structures can help narrow the differential diagnosis. Online supplemental material is available for this article. ©RSNA, 2021.

Chromophobe Renal Cell Carcinoma with Radiologic-Pathologic Correlation.

Renal cell carcinoma (RCC) is a heterogeneous group of neoplasms derived from the renal tubular epithelial cells. Chromophobe RCC (chRCC) is the third most common subtype of RCC, accounting for 5% of cases. chRCC may be detected as an incidental finding or less commonly may manifest with clinical symptoms. The mainstay of therapy for chRCC is surgical resection. chRCC has a better prognosis compared with the more common clear cell RCC. At gross pathologic analysis, chRCC is a solid well-defined mass with lobulated borders. Histologic findings vary by subtype but include large pale polygonal cells with abundant transparent cytoplasm, crinkled "raisinoid" nuclei with perinuclear halos, and prominent cell membranes. Pathologic analysis reveals only moderate vascularity. The most common imaging pattern is a predominantly solid renal mass with circumscribed margins and enhancement less than that of the renal cortex. The authors discuss chRCC with emphasis on correlative pathologic findings and illustrate the multimodality imaging appearances of chRCC by using cases from the Radiologic Pathology Archives of the American Institute for Radiologic Pathology. ©RSNA, 2021.

DWI and ADC value versus ADC ratio in the characterization of solid renal masses: radiologic-pathologic correlation

BackgroundRenal masses are becoming an increasingly common finding on cross-sectional images. Characterization of the nature of the lesion either neoplastic or not, benign or malignant as well as further subtype characterization is becoming an important factor in determining management plan. The purpose of our study with to assess the sensitivity and specificity of both ADC mean value and ADC ratio in such characterization along with the calculation of different cutoff values to differentiate between different varieties, using pathological data as the main gold standard for diagnosis.ResultsOur study included 50 patients with a total of 72 masses. A final diagnosis was reached in 69 masses by pathological examination and three masses had clinical and laboratory signs of infection. We had a total of 49 malignant lesions (68%) and 23 benign lesions (32%). The ADC value of ccRCC (1.4 × 10−3 mm2/s) was significantly higher than all other renal masses. A cutoff ADC value of > 1.1 and a cutoff ADC ratio of > 0.56 can be used to differentiate between clear cell renal cell carcinoma and other lesions and an ADC value of < 0.8 and an ADC ratio of ≤ 0.56 to differentiate papillary renal cell carcinoma from other masses. There was no statistically significant ADC value to differentiate between benign and malignant lesions but a statistically significant ADC ratio (> 0.52) was reached.ConclusionADC value and ADC ratio can be used as an adjunct tool in the characterization of different renal masses, with ADC ratio having a higher sensitivity, which can affect the prognosis and management of the patient.

A prospective study of dual-energy computed tomography for differentiating metastatic and non-metastatic lymph nodes of colorectal cancer.

Colorectal cancer (CRC) is the third most common malignancy worldwide, and lymph node metastasis is considered to be a risk factor for local recurrence and a poor prognosis in colorectal cancer. However, there remains a lack of reliable and non-invasive biomarkers to identify the lymph node status of CRC patients preoperatively. The purpose of this study was to explore the ability of dual-energy computed tomography (DECT) to differentiate metastatic from non-metastatic lymph nodes in colorectal cancer. Seventy-one patients with primary colorectal cancer underwent contrast-enhanced dual-energy computed tomography imaging preoperatively. The colorectal specimen was scanned postoperatively, and lymph nodes were matched to the pathology report. The following dual-energy computed tomography quantitative parameters were analyzed: dual-energy curve slope value (λHU), standardized iodine concentration (n△HU), iodine water ratio (nIWR), electron density value (nρeff), and effective atom-number (nZ), based on metastatic and non-metastatic lymph node differentiation. Also, sensitivity and specificity analyses were performed using receiver operating characteristic curves. In all patients, one hundred and fifty lymph nodes, including 66 non-metastatic and 84 metastatic lymph nodes, were matched using the radiological-pathological correlation. Metastatic nodes had significantly greater λHU, n△HU, and nIWR values than non-metastatic nodes in both the arterial and venous phases (P<0.01). The area under curve (AUC), sensitivity, and specificity were 0.80, 80%, and 66% for λHU; 0.86, 70%, and 95% for n△HU; and 0.88, 71%, and 95% for nIWR in the arterial phase. There was no significant difference in electron density and effective Z values between metastatic and non-metastatic lymph nodes. DECT quantitative parameters may help differentiate between metastatic and normal lymph nodes in patients with CRC.

Tomosynthesis-Guided Vacuum-Assisted Breast Biopsy of Architectural Distortion Without a Sonographic Correlate: A Retrospective Review.

BACKGROUND. Digital breast tomosynthesis-guided vacuum-assisted breast biopsy (DBT VAB) allows biopsy of findings seen better or exclusively on digital breast tomosynthesis (DBT), including architectural distortion. Although architectural distortion with an associated sonographic mass correlate has a high risk of malignancy, limited data describe the radiologic-pathologic correlation of tomosynthesis-detected architectural distortion without a sonographic correlate. OBJECTIVE. This study evaluates the malignancy rate of architectural distortions without a sonographic correlate that undergo DBT VAB and provides radiologic-pathologic correlation for benign, high-risk, and malignant entities that are associated with architectural distortion. METHODS. We retrospectively reviewed imaging, as well as pathology slides and/or reports, for DBT VABs performed for architectural distortion without a sonographic correlate at a single institution between June 1, 2017, and January 15, 2020. According to the correlative histopathology, cases were categorized as benign, high risk, or malignant, and specific histopathologic diagnoses were summarized. RESULTS. During the study period, 142 patients (mean age, 59 years) underwent DBT VAB for 151 unique architectural distortions without a sonographic correlate. DBT VAB revealed a malignant diagnosis in 27 (18%), a high-risk lesion in 50 (33%), and a benign diagnosis in 74 (49%). Two cases of atypical ductal hyperplasia were upgraded to malignancy, resulting in a final malignancy rate of 19% (n = 29/151). Most malignant lesions were invasive carcinomas (83%, n = 24/29); most invasive carcinomas were of lobular subtype (54%, n = 13/24). Most high-risk lesions were radial scars/complex sclerosing lesions (62%, n = 31/50). Most benign results represented fibrocystic change (66%, n = 49/74). A subset (11%, n = 8/74) of benign results were considered discordant and subsequently excised, with none representing malignancy. CONCLUSION. The final malignancy rate of 19% in architectural distortion without a sonographic correlate justifies a recommendation for biopsy using DBT VAB. CLINICAL IMPACT. Our results highlight the utility of DBT VAB in the era of DBT. The detailed radiologic-pathologic correlations will assist radiologists in assessing concordance when performing DBT VAB for architectural distortions and provide a reference for future patient management.

Reticular enhancement of the submandibular gland on contrast-enhanced magnetic resonance imaging in three cases with IgG4-related chronic sclerosing sialadenitis.

The present case study reports contrast-enhanced magnetic resonance findings in three patients with histopathologically proven IgG4-related chronic sclerosing sialadenitis of the submandibular gland. All three patients presented with painless swelling of the submandibular region. The contrast-enhanced T1-weighted images showed reticular enhancement of the swollen submandibular gland. Radiological-pathological correlation revealed that the characteristic reticular enhancement corresponded to fibrosis and to inflammatory cell infiltration in the interlobular septa and in the periductal region of the submandibular gland.

Axillary fibromatosis with radiological-pathological correlation: a case report and literature review

BackgroundThe term fibromatosis refers to a spectrum of soft tissue tumors resulting from the unbridled proliferation of fibroblasts, with high infiltrative power. It is a rare neoplasm, with an incidence of about 3 cases per million. Most common sites include the abdominal wall and cavity, chest wall, scapular area, and the limbs, rarely affecting the axilla. Imaging plays a major role in surgical planning and clinical follow-up. Differential diagnosis with other soft tissue tumors may be arduous, but a correct evaluation is fundamental.Case presentationA 33-year-old case is reported for the evaluation of a palpable hardened and immobile left axillary nodule. The ultrasound reveals a solid, elongated, heterogeneous, poorly delimited, infiltrative lesion observed in the left axillary hollow, with no detectable flow in the color Doppler mode. At magnetic resonance imaging, the same elongated and expansive lesion was better defined, revealing its irregular contours, alternating areas of hypo- and hyperintense on T2, heterogeneous enhancement, and no signs of signal decay on in- and out-of-phase sequences. Due to its growth and local invasion potential, surgical excision was performed. The microscopic analysis showed long and uniform spindle cell fascicles, with clear cytoplasm and wavy nuclei, arranged in different directions, included in collagen stroma. Immunohistochemistry was positive for nuclear beta-catenin, confirming the diagnosis of fibromatosis.ConclusionImaging methods reflect the heterogeneous nature of the lesion. This study demonstrates the importance of using a multidisciplinary approach in addition to imaging tests and histopathological study for better diagnosis and therapeutic planning. The high infiltrative power always must be reminded of, since it affects young patients and diagnosis delay can lead to mutilating surgeries.

MRI Response to Pre-operative Stereotactic Ablative Body Radiotherapy (SABR) in Early Stage ER/PR+ HER2- Breast Cancer correlates with Surgical Pathology Tumor Bed Cellularity

ObjectiveThis study evaluates breast MRI response of ER/PR+ HER2- breast tumors to pre-operative SABR with pathologic response correlation. MethodsWomen enrolled in a phase 2 single institution trial of SABR for ER/PR+ HER2- breast cancer were retrospectively evaluated for radiologic-pathologic correlation of tumor response. These patients underwent baseline breast MRI, SABR (28.5 Gy in 3 fractions), follow-up MRI 5 to 6 weeks post-SABR, and lumpectomy. Tumor size and BI-RADS descriptors on pre and post-SABR breast MRIs were compared to determine correlation with surgical specimen % tumor cellularity (%TC). Reported MRI tumor dimensions were used to calculate percent cubic volume remaining (%VR). Partial MRI response was defined as a BI-RADs descriptor change or %VR ≤ 70%, while partial pathologic response (pPR) was defined as %TC ≤ 70%. ResultsNineteen patients completed the trial, and %TC ranged 10% to 80%. For BI-RADS descriptor analysis, 12 of 19 (63%) showed change in lesion or kinetic enhancement descriptors post-SABR. This was associated with lower %TC (29% vs. 47%, P = .042). BI-RADS descriptor change analysis also demonstrated high PPV (100%) and specificity (100%) for predicting pPR to treatment (sensitivity 71%, accuracy 74%), but low NPV (29%). MRI %VR demonstrated strong linear correlation with %TC (R = 0.70, P < .001, Pearson's Correlation) and high accuracy (89%) for predicting pPR (sensitivity 88%, specificity 100%, PPV 100%, and NPV 50%). ConclusionEvaluating breast cancer response on MRI using %VR after pre-operative SABR treatment can help identify patients benefiting the most from neoadjuvant radiation treatment of their ER/PR+ HER2- tumors, a group in which pCR to neoadjuvant therapy is rare.

Mucocele-like lesions of the breast - A radiological and clinicopathological analysis

Introduction: Mucocele-like lesions (MLL) of the breast are rare entities which are considered to harbor uncertain malignant potential. Current UK guidelines recommend vacuum assisted excision (VAE) of all such lesions regardless of whether they display epithelial atypia. This study sought to review the key histological and radiological features of MLLs and compare their differing outcomes based on the presence of epithelial atypia.Methods: Pathology records of a single breast cancer screening center were retrospectively searched for all biopsy diagnosed MLLs over an 11-year period. Upgrade rates to malignancy (positive predictive values) were calculated by reviewing histology from the initial core biopsy and comparing with the corresponding excision specimen. Radiological images were simultaneously reviewed to provide radiological-pathological correlation.Results: Three of 11 patients (27.3%) with atypical MLLs on biopsy had malignant outcomes at excision, compared with only 1 of 36 patients (2.8%) with non-atypical MLLs. The majority of MLLs (93%) were identified as microcalcifications on mammographic imaging. No specific radiological features were predictive of malignancy.Conclusions: Our data suggest that MLLs without atypia are potentially overtreated with current protocols and could be managed conservatively with radiological follow up. Radiological-pathological correlation is essential.

Analysis of 612 Benign Papillomas Diagnosed at Core Biopsy: Rate of Upgrade to Malignancy, Factors Associated With Upgrade, and a Proposal for Selective Surgical Excision.

BACKGROUND. Despite numerous published studies, management of benign papillomas without atypia remains controversial. OBJECTIVE. The purpose of this study was to determine the malignancy upgrade rate of benign papillomas, identify risk factors for upgrade, and formulate criteria for selective surgery. METHODS. This retrospective study included benign papillomas without atypia diagnosed on percutaneous biopsy between December 1, 2000, and December 31, 2019. Papillomas that did not undergo surgical excision or at least 2 years of imaging and/or clinical follow-up were excluded. Clinical, imaging, and histopathologic features were extracted from the electronic medical record. Features associated with upgrade to malignancy were identified. Multivariable logistic regression was performed. RESULTS. The study included 612 benign papillomas in 543 women (mean age, 54.5 ± 12.1 [SD] years); 466 papillomas were excised, and 146 underwent imaging or clinical surveillance. The upgrade rate to malignancy was 2.3% (14/612). Upgrade rate was associated (p < .05) with radiology-pathology correlation (50.0% if discordant vs 2.1% if concordant), patient age (5.6% for 60 years and older vs 0.7% for younger than 60 years), presenting symptoms (6.7% if palpable mass or pathologic nipple discharge vs 1.3% if no symptoms), and lesion size (7.3% if ≥ 10 mm vs 0.6% if < 10 mm). Three of 14 upgraded papillomas were associated with four or more metachronous or concurrent peripheral papillomas. No incidental papilloma or papilloma reported as completely excised on core biopsy histopathologic analysis was upgraded. A predictive model combining radiology-pathology discordance, symptoms (palpable mass or nipple discharge), age 60 years old and older, size 10 mm or larger, and presence of four or more metachronous or concurrent peripheral papillomas achieved an AUC of 0.91, sensitivity of 79%, and spec-ificity of 89% for upgrade. Selective surgery based on presence of any of these five factors, although excluding from surgery incidental papillomas and papillomas reported as completely excised on histopathology, would have spared 294 of 612 lesions from routine excision and identified all 14 upgraded lesions. CONCLUSION. Benign nonatypical papillomas have a low malignancy upgrade rate; routine surgical excision may not be necessary. Selective excision is recommended for lesions satisfying any of the five criteria. Incidental papillomas or papillomas completely excised on histopathology may undergo imaging follow-up. CLINICAL IMPACT. The proposed criteria for selective surgery of benign papillomas on core biopsy would reduce surgeries without delaying diagnosis of malignancy.

In Memoriam

In Memoriam

Identification of hippocampal cortical microinfarcts on postmortem 3-T magnetic resonance imaging

Cortical microinfarcts (CMI) are increasingly recognized in the neurological community as a biomarker related to cognitive impairment and dementia. If their radiological depiction has been largely described in experimental settings using ultra-high-field magnetic resonance imaging (MRI), less is known about their visibility on routinely used 3-T MRI. In this radiologic-pathologic correlation study, using 3-T post-mortem MRI, we searched for hippocampal CMI, in a double-blinded fashion, and found that only 4/36, or 11%, were clearly demonstrated on both radiological and histopathological exams.

Tissue clearing techniques for three-dimensional optical imaging of intact human prostate and correlations with multi-parametric MRI.

Tissue clearing technologies have enabled remarkable advancements for in situ characterization of tissues and exploration of the three-dimensional (3D) relationships between cells, however, these studies have predominantly been performed in non-human tissues and correlative assessment with clinical imaging has yet to be explored. We sought to evaluate the feasibility of tissue clearing technologies for3Dimaging of intact human prostate and the mapping of structurally and molecularly preserved pathology data with multi-parametric volumetric MR imaging (mpMRI). Whole-mount prostates were processed with either hydrogel-based CLARITY or solvent-based iDISCO. The samples were stained with a nuclear dye or fluorescently labeled with antibodies against androgen receptor, alpha-methylacyl coenzyme-A racemase, or p63, and then imaged with 3D confocal microscopy. The apparent diffusion coefficientand Ktrans maps were computed from preoperative mpMRI. Quantitative analysis of cleared normal and tumor prostate tissue volumes displayed differences in 3D tissue architecture, marker-specific cell staining, and cell densities that were significantly correlated with mpMRI measurements in this initial, pilot cohort. 3D imaging of human prostate volumes following tissue clearing is a feasible technique for quantitative radiology-pathology correlation analysis with mpMRI and provides an opportunity to explore functional relationships between cellular structures and cross-sectional clinical imaging.

Management of Lobular Neoplasia Found on Core Needle Biopsy Performed for Calcifications Using Precise Radiologic-Pathologic Correlation.

OBJECTIVE. The purpose of our study was to evaluate the upgrade rate of calcified lobular neoplasia (LN) versus incidental noncalcified classic LN found on core needle biopsy performed for the evaluation of suspicious calcifications. MATERIALS AND METHODS. This retrospective study included 390 consecutive image-guided breast core needle biopsies with microcalcifications as the target that were performed between December 2009 and July 2017. In 81 of the 390 core biopsies, the highest-risk lesion was LN that then underwent either excision or imaging follow-up. Core biopsy results were compared with excision and imaging follow-up findings. An upgrade of LN was defined as ductal carcinoma in situ or invasive ductal or lobular carcinoma. RESULTS. Of 81 LN diagnosed on core biopsy performed for calcifications, 16 had calcifications within the LN. Fifteen of these 16 cases underwent surgical excision, and three (3/15, 20.0%) were upgraded on excision. Of the 64 core biopsies showing incidental noncalcified LN with benign concordant entities containing calcifications, 42 underwent surgical excision, and one LN (1/42, 2.4%) was upgraded. Twenty-three total lesions (one calcified LN and 22 noncalcified LN) were followed with imaging rather than excision. No cancers were detected among the follow-up group. One case was deemed to have discordant findings on radiologic-pathologic review and was sent for excision, which showed invasive cancer with tubulolobular and lobular features. CONCLUSION. Women undergoing stereotactic core needle biopsy for calcifications revealing noncalcified incidental classic LN and a benign concordant entity that could explain the presence of the target calcifications have a low risk of upgrade and may be followed with imaging. Surgical excision should be offered to women who have LN with calcifications.

Closing the communication loop between gynecological surgeons, diagnostic imaging experts and pathologists in endometriosis: building bridges between specialties.

Closing the communication loop between gynecological surgeons, diagnostic imaging experts and pathologists in endometriosis: building bridges between specialties.

Imaging response evaluation after neoadjuvant treatment in soft tissue sarcomas: Where do we stand?

Soft tissue sarcomas (STS) represent a broad family of rare tumours for which surgery with radiotherapy represents first-line treatment. Recently, neoadjuvant chemo-radiotherapy has been increasingly used in high-risk patients in an effort to reduce surgical morbidity and improve clinical outcomes. An adequate understanding of the efficacy of neoadjuvant therapies would optimise patient care, allowing a tailored approach. Although response evaluation criteria in solid tumours (RECIST) is the most common imaging method to assess tumour response, Choi criteria and functional and molecular imaging (DWI, DCE-MRI and 18F-FDG-PET) seem to outperform it in the discrimination between responders and non-responders. Moreover, the radiologic-pathology correlation of treatment-related changes remains poorly understood. In this review, we provide an overview of the imaging assessment of tumour response in STS undergoing neoadjuvant treatment, including conventional imaging (CT, MRI, PET) and advanced imaging analysis. Future directions will be presented to shed light on potential advances in pre-surgical imaging assessments that have clinical implications for sarcoma patients.

Lobular neoplasia detected at MRI-guided biopsy: imaging findings and outcomes

ObjectiveTo review MRI findings of pure lobular neoplasia (LN) on MRI guided biopsy, evaluate surgical and clinical outcomes, and assess imaging findings predictive of upgrade to malignancy. MethodsHIPAA compliant, IRB-approved retrospective review of our MRI-guided breast biopsy database from October 2008–January 2015. Biopsies yielding atypical lobular hyperplasia or lobular carcinoma in situ were included in the analysis; all biopsy slides were reviewed by a dedicated breast pathologist. Imaging indications, MRI findings, and histopathology were reviewed. Statistical analysis was performed using the two-tailed Fisher exact-test and the t-test, and 95% CIs were determined. A p < 0.05 was considered statistically significant. ResultsDatabase search yielded 943 biopsies in 785 patients of which 65/943 (6.9%) reported LN as the highest risk pathologic lesion. Of 65 cases, 32 were found to have LN as the dominant finding on pathology and constituted the study population. All 32 findings were mammographically and sonographically occult. Three of 32 (9.3%) cases of lobular neoplasia were upgraded to malignancy, all LCIS (one pleomorphic and two classical). The most common MRI finding was focal, heterogenous non-mass enhancement with low T2 signal. No clinical features or imaging findings were predictive of upgrade to malignancy. ConclusionIncidence of pure lobular neoplasia on MRI guided biopsy is low, with comparatively low incidence of upgrade to malignancy. No imaging or clinical features are predictive of upgrade on surgical excision, therefore, prudent radiologic-pathologic correlation is necessary.

An atypically located pleomorphic adenoma: Radiological and pathological correlation

Pleomorphic adenoma is a common benign salivary gland neoplasm which very rarely occurs in the breast. Its radiologic and pathologic appearance may be mistaken for other benign or malignant lesions such as a fibroadenoma or invasive ductal carcinoma. Due to the risk of local recurrence and, rarely, malignant transformation, wide local excision with clear margins is recommended. As such, a correct diagnosis of this lesion is important to ensure appropriate surgical treatment. We report a case of an atypically located pleomorphic adenoma with radiologic-pathologic correlation in an asymptomatic 63-year-old woman.