Software-based risk stratification of pulmonary adenocarcinomas manifesting as pure ground glass nodules on computed tomography.

OBJECTIVES: To assess the performance of the "Computer-Aided Nodule Assessment and Risk Yield" (CANARY) software in the differentiation and risk assessment of histological subtypes of lung adenocarcinomas manifesting as pure ground glass nodules on computed tomography (CT). METHODS: 64 surgically resected and histologically proven adenocarcinomas manifesting as pure ground-glass nodules on CT were assessed using CANARY software, which classifies voxel-densities into three risk components (low, intermediate, and high risk). Differences in risk components between histological adenocarcinoma subtypes were analysed. To determine the optimal threshold reflecting the presence of an invasive focus, sensitivity, specificity, negative predictive value, and positive predictive value were calculated. RESULTS: 28/64 (44%) were adenocarcinomas in situ (AIS); 26/64 (41%) were minimally invasive adenocarcinomas (MIA); and 10/64 (16%) were invasive ACs (IAC). The software showed significant differences in risk components between histological subtypes (P<0.001-0.003). A relative volume of 45% or less of low-risk components was associated with histological invasiveness (specificity 100%, positive predictive value 100%). CONCLUSIONS: CANARY-based risk assessment of ACs manifesting as pure ground glass nodules on CT allows the differentiation of their histological subtypes. A threshold of 45% of low-risk components reflects invasiveness in these groups. KEY POINTS: • CANARY-based risk assessment allows the differentiation of their histological subtypes. • 45% or less of low-risk component reflects histological invasiveness. • CANARY has potential role in suspected adenocarcinomas manifesting as pure ground-glass nodules.

Lymphocytic ganglionitis leading to megacolon in lymphocyte-rich glioblastoma.

T-cell immune attack of cancer cells underlies the efficacy of immune checkpoint inhibitors in many cancer subtypes, but is not yet well established in the primary brain cancer glioblastoma. Immune checkpoint inhibitor treatments that disinhibit the immune system to enhance immune clearance of cancer have in rare cases resulted in T-cell attack of peripheral ganglia causing lymphocytic ganglionitis. In glioblastoma, lymphocytic ganglionitis has not been reported and checkpoint inhibitors are not routinely used. Here we report a case of glioblastoma not treated with checkpoint inhibitors in which the primary tumor and peripheral ganglia of the celiac and sympathetic chains, as well as myenteric plexus, are infiltrated by CD8+ cytotoxic T-cells. In addition to the marked lymphocytic infiltrates, this case is also notable for an unusually long survival (8 years) after diagnosis with glioblastoma, but an ultimately fatal outcome due to ileus. The findings suggest T-cell immune attack of glioblastoma may prolong survival, but also suggest T-cell autoimmune diseases such as lymphocytic ganglionitis could become a risk with the future use of immune-targeted therapies for glioblastoma.

Frozen-Section Checklist Implementation Improves Quality and Patient Safety.

OBJECTIVES: An intraoperative consultation (IOC) checklist was developed and implemented aimed at standardizing slide labeling and monitoring metrics central to quality and safety in surgical pathology. DESIGN: Data were collected for all IOC cases over a 9-month period. Slide labeling defect rates and IOC turnaround time (TAT) were recorded and compared for the pre- and postimplementation periods. RESULTS: In total, 839 IOC cases were analyzed. Preintervention slide labeling showed that 85% of cases contained at least one defect (n = 565). Postintervention data revealed that 27% of cases contained at least one defect (n = 274). The improvement was statistically significant (P < .001). Mean TAT was 21.6 minutes preintervention vs 23.2 minutes postintervention, and the change was insignificant (P = .071). CONCLUSIONS: The implementation of a standardized IOC reduced slide labeling error. This improvement did not affect mean TAT and may have the increased quality of IOC TAT data reporting. Other metrics affecting patient safety and quality were monitored and standardized.

Visceral Pleural Invasion in Pulmonary Adenocarcinoma: Differences in CT Patterns between Solid and Subsolid Cancers.

PURPOSE: To analyze the incidence and CT patterns of visceral pleural invasion (VPI) in adenocarcinomas on the basis of their CT presentation as solid or subsolid nodules. MATERIALS AND METHODS: A total of 286 adenocarcinomas in direct contact with a pleural surface, resected at an institution between 2005 and 2016, were included in this retrospective, institutional review board-approved study. CT size and longest contact length with a pleural surface were measured and their ratios computed. Pleural deviation, pleural thickening, spiculations, different pleural tag types, pleural effusion, and the CT appearance of transgression into an adjacent lobe or infiltration of surrounding tissue were evaluated. Fisher exact tests and simple and multiple logistic regression models were used. RESULTS: Of the 286 nodules, 179 of 286 (62.6%) were solid and 107 of 286 (37.4%) were subsolid. VPI was present in 49 of 286 (17.1%) nodules and was significantly more frequent in solid (44 of 179; 24.6%) than in subsolid nodules (five of 107; 4.7%; P < .001). In solid nodules, multiple regression analysis showed an association of higher contact length-to-size ratio (adjusted odds ratio [OR], 1.02; P = .007) and the presence of multiple pleural tag types (adjusted OR, 5.88; P = .002) with VPI. In subsolid nodules, longer pleural contact length of the solid nodular component (adjusted OR, 1.27; P = .017) and the CT appearance of transgression or infiltration (adjusted OR, 10.75; P = .037) were associated with VPI. CONCLUSION: During preoperative evaluation of adenocarcinomas for the likelihood of VPI, whether a tumor manifests as a solid or a subsolid nodule is important to consider because the incidence of VPI is significantly higher in solid than in subsolid nodules. In addition, this study showed that the CT patterns associated with VPI differ between solid and subsolid nodules.© RSNA, 2019Supplemental material is available for this article.See also the commentary by Elicker in this issue.

Synchronous granular cell tumors of the pancreas and cecum.

Granular cell tumors (GCT) are rare and typically benign. Diagnosis is challenging due to nonspecific imaging characteristics and symptomatology. Herein, we report a combination of pancreatic/cecal GCTs in a 43-year-old man. Contrast enhanced MDCT demonstrated a 1.5 cm well-defined homogeneous intraluminal cecal mass and a 1.6 cm slightly hypervascular pancreatic body mass. On MRI, the pancreatic mass showed increased enhancement on post-gadolinium delayed sequences. Diagnosis was confirmed by excisional pathology (S100 and CD68, PAS-D positive). Radiologists, gastroenterologists, and surgeons should ponder the possibility of GCTs in the differential diagnosis of any small, pancreatic or cecal well-defined tumor.

Pathologic T Descriptor of Nonmucinous Lung Adenocarcinomas Now Based on Invasive Tumor Size: How Should Pathologists Measure Invasion?

OBJECTIVES: The eighth edition of the American Joint Committee on Cancer staging manual now stratifies nonmucinous lung adenocarcinomas (nmLACAs) by the size of the invasive component only. This is determined by direct gross or microscopic measurement; however, a calculated invasive size based on the percentage of invasive growth patterns has been proposed as an alternative option. METHODS: To compare radiologic with different pathologic assessments of invasive tumor size, we retrospectively reviewed a cohort of resected nmLACAs with a part-solid appearance on computed tomography (CT) scan (n = 112). RESULTS: The median direct microscopic pathologic invasive measurements were not significantly different from the median calculated pathologic invasive measurements; however, the median CT invasive measurements were 0.26 cm larger than the median direct pathologic measurements (P < .001). CONCLUSIONS: Our results show that pathologic calculated invasive tumor measurements are comparable to direct microscopic measurements of invasive tumor, thereby supporting the recommendation for use of calculated invasive tumor size by the pathologist if necessary.

Measurement Bias of Gross Pathologic Compared With Radiologic Tumor Size of Resected Lung Adenocarcinomas: Implications for the T-Stage Revisions in the Eighth Edition of the American Joint Committee on Cancer Staging Manual.

OBJECTIVES: The eighth edition of the AJCC Cancer Staging Manual now stratifies the T descriptor for lung cancers by each increasing 1.0 cm increment, up to 5.0 cm, with an additional category for tumor greater than 7.0 cm. Bias in pathologic versus radiologic measurements may impact tumor staging. METHODS: The gross pathologic measurements of 493 resected lung adenocarcinomas were compared with presurgical computed tomography radiologic measurements. Also, pathologic tumor measurement data from the Surveillance, Epidemiology, and End Results (SEER) program database were examined. RESULTS: The distribution of pathologic measurements showed clustering at 0.5-cm increments, with 43.0% of pathologic measurements falling on 0.5-cm increments compared to only 20.3% of radiologic measurements. This pathologic measurement clustering was also observed for both 591,691 resected lung cancers and 3,597,685 tumors of any type from the SEER database. CONCLUSIONS: Compared to radiologic measurements, gross pathologic measurements cluster around whole- and half-cm values. This measurement bias could lead to incorrect pathologic tumor staging and influence clinical treatment plans.

Size Measurement and T-staging of Lung Adenocarcinomas Manifesting as Solid Nodules ≤30 mm on CT: Radiology-Pathology Correlation.

RATIONALE AND OBJECTIVES: This study aimed to compare long-axis diameter to average computed tomography (CT) diameter measurements of lung adenocarcinomas manifesting as solid lung nodules ≤30 mm on CT, as referenced to pathologic measurements, and to determine the impact of the two CT measurement approaches on tumor (T)-staging of nodules. MATERIALS AND METHODS: This institutional review board-approved study included all 274 radiologic solid adenocarcinomas resected at our institution over 10 years. Two observers measured long- and short-axis diameters on pre-resection chest CT in lung and mediastinal windows. T-stages were determined. CT measurements and T-stages were compared to pathology measurements and T-stages using Wilcoxon signed rank test and McNemar test. Inter- and intraobserver variability was determined with intraclass correlation coefficients (ICC) and Bland-Altman plots. RESULTS: For lung and mediastinal windows, nodule size was significantly larger using long-axis diameter rather than average diameter (16.93 vs. 14.92 mm, P <.001; and 14.02 vs. 12.17 mm, P <.001, respectively). The correlation of CT with pathologic measurements was stronger with long-axis than with average diameter (ICC 0.808 vs. 0.730; and 0.731 vs. 0.621, respectively). Lung window measurements correlated stronger with pathology than mediastinal window measurements. CT T-stages differed from pathology T-stages in more than 20% of nodules (P <.001). Inter- and intraobserver variability was small with long-axis and average diameter (ICC range 0.96-0.991, and 0.970-0.993, respectively), but long-axis diameter showed wider scatter on Bland-Altman plots. CONCLUSIONS: Long-axis CT diameter is preferable for T-staging because it better reflects the pathology T-stage. Average CT diameter might be used for longitudinal nodule follow-up because it shows less measurement variability and is more conservative in size assessment.

Lung Adenocarcinoma Manifesting as Pure Ground-Glass Nodules: Correlating CT Size, Volume, Density, and Roundness with Histopathologic Invasion and Size.

OBJECTIVES: The aims of this study were to quantify the relationship between computed tomography (CT) size, volume, density, and roundness of lung adenocarcinomas (ACs) manifesting as pure ground-glass nodules (pGGNs) on CT images and to correlate these parameters with histologic features of invasiveness. METHODS: From 2005 to 2015, 63 ACs manifesting as pGGNs on CT images were surgically resected at our institution. CT size was measured, and roundness, volumes and densities were computed. CT parameters were correlated to age and sex, as well as to size and number of invasive foci and histologic AC subcategories. Correlations were quantified with Spearman rank correlation coefficients. RESULTS: Of 63 ACs, 28 (44%) were AC in situ, 25 (40%) were minimally invasive AC, and 10 (16%) were invasive AC. Six of 35 nodules with invasive foci (17%) were smaller than 10 mm. Correlations between age and CT size, volume, density, and roundness were not significant (range r = -0.061 to 0.144, p = 0.285 to 0.902). Correlations between size and number of invasive foci with CT size (r = 0.417, p < 0.001 and r = 0.389, p = 0.003, respectively) were similar to the correlations with volume (r = 0.401, p = 0.001 and r = 0.350, p = 0.005, respectively) and stronger than the correlation with density (r = 0.237, p = 0.062 and r = 0.222, p = 0.081, respectively) and roundness (r = 0.059, p = 0.648 and r = -0.030, p = 0.831, respectively). CONCLUSIONS: In ACs manifesting as pGGNs on CT images, nodule size is positively related to size and number of histologically invasive foci. However, invasive foci can be found in pGGNs smaller than 10 mm. Measuring volume and density of pGGNs provides no advantage over two-dimensional size measurements, which appear sufficient for risk estimation in clinical practice.

"Rounding" the Size of Pulmonary Nodules: Impact of Rounding Methods on Nodule Management, as Defined by the 2017 Fleischner Society Guidelines.

RATIONALE AND OBJECTIVES: The objective of this study was to quantify the impact of different rounding methods on size measurements of pulmonary nodules and to determine the number of nodules that change management categories as a result of rounding. MATERIALS AND METHODS: For this retrospective institutional review board-approved study, we included 503 incidental pulmonary nodules (308 solid and 195 subsolid) from a data repository. Long and short axes were measured. Average diameters were calculated using four different rounding methods (method 1: no rounding; method 2: rounding only the average diameter to the closest millimeter; method 3: rounding only short and long axes; and method 4: rounding short and long axes and the average diameter to the closest millimeter). Nodules were classified for each rounding method according to the 2017 Fleischner Society guideline management categories. Measurements were compared among the four rounding methods using analysis of variance. RESULTS: Without rounding, the average nodule diameter was 15.67 ± 5.97 mm. This increased between 0.03 and 0.29 mm using rounding methods 2-4 (range: P < 0.001-0.017). The nodule size was more frequently rounded up (range: 52.1%-77.5%) than rounded down (range: 17.7%-42.5%) using rounding methods 2-4, as compared to no rounding. In the 308 solid nodules, up to 2.9% of the nodules changed management category, whereas none of the 195 subsolid nodules changed category. CONCLUSIONS: Rounding methods have a small absolute but statically significant effect on nodule size, impacting management category in less than 3% of the nodules. This suggests that, in clinical practice, any rounding method can be used for determining nodule size without substantially biasing individual nodules toward given management categories.

Anatomic and physiologic considerations in ureteroscopy.

The successful and safe implementation of ureteroscopic techniques depends on considerations of anatomy and physiology. Combining knowledge of the drainage system of the kidney with its vascular supply, predictive patterns of incisions can be applied within the collecting system to safely avoid vascular injury. In addition, awareness of the variation in normal and pathologic anatomy and physiology is key to effective interventions. An appreciation of the impact of ureteroscopy on normal anatomy and physiology can prevent complications and promote improved therapeutic outcomes.

Clinical and histological significance of the testicular remnant found on inguinal exploration after diagnostic laparoscopy in the absence of a patent processus vaginalis.

PURPOSE: We reviewed the histological findings of cord structures excised at inguinal exploration after diagnostic laparoscopy in patients with a nonpalpable testis with the vas deferens and spermatic vessels exiting the internal inguinal ring in the absence of a patent processus vaginalis. MATERIALS AND METHODS: A retrospective review of 809 laparoscopic explorations for nonpalpable testes between 1981 and 2003 was conducted. The histological findings of the excised remnants of those patients with a closed processus vaginalis were reviewed. RESULTS: A total of 110 patients underwent excision of a testicular remnant at inguinal exploration in association with a closed processus vaginalis. Of the specimens 31 (28%) were on the right side and 79 (72%) were on the left side. The incidence of viable germ cell elements was 8 of 110 (7%). The presence of hemosiderin, calcification and fibrosis was identified in all 8 remnants with viable germ cell elements. CONCLUSIONS: The incidence of viable germ cell elements in the excised remnant when the vas deferens and spermatic vessels are identified exiting a closed internal ring in patients with a nonpalpable testis is 7%. To our knowledge no prior study has evaluated the incidence of viable germ cell elements in remnants associated with a closed internal inguinal ring. Based on these findings, we advocate inguinal exploration and excision of testicular remnants in these patients.