Jordan Reynolds

Most prior studies of primary diagnosis in surgical pathology using whole slide imaging (WSI) versus microscopy have focused on specific organ systems or included relatively few cases. The objective of this study was to demonstrate that WSI is noninferior to microscopy for primary diagnosis in surgical pathology. A blinded randomized noninferiority study was conducted across the entire range of surgical pathology cases (biopsies and resections, including hematoxylin and eosin, immunohistochemistry, and special stains) from 4 institutions using the original sign-out diagnosis (baseline diagnosis) as the reference standard. Cases were scanned, converted to WSI and randomized. Sixteen pathologists interpreted cases by microscopy or WSI, followed by a wash-out period of ≥4 weeks, after which cases were read by the same observers using the other modality. Major discordances were identified by an adjudication panel, and the differences between major discordance rates for both microscopy (against the reference standard) and WSI (against the reference standard) were calculated. A total of 1992 cases were included, resulting in 15,925 reads. The major discordance rate with the reference standard diagnosis was 4.9% for WSI and 4.6% for microscopy. The difference between major discordance rates for microscopy and WSI was 0.4% (95% confidence interval, -0.30% to 1.01%). The difference in major discordance rates for WSI and microscopy was highest in endocrine pathology (1.8%), neoplastic kidney pathology (1.5%), urinary bladder pathology (1.3%), and gynecologic pathology (1.2%). Detailed analysis of these cases revealed no instances where interpretation by WSI was consistently inaccurate compared with microscopy for multiple observers. We conclude that WSI is noninferior to microscopy for primary diagnosis in surgical pathology, including biopsies and resections stained with hematoxylin and eosin, immunohistochemistry and special stains. This conclusion is valid across a wide variety of organ systems and specimen types.

OBJECTIVES: Metastases to the thyroid gland are not as unusual as previously believed. This study reports the largest number of patients with metastatic disease of the thyroid to date, confirms the accuracy of fine-needle aspiration (FNA) in diagnosing metastasis, and reviews the incidence and management through our institutional experience. METHODS: This study entailed review of all thyroid FNAs performed at Mayo Clinic, Rochester during the period 1980 to 2010 and identified 97 patients with a metastatic solid neoplasm of the thyroid gland. RESULTS: Frequent primary tumor sites included kidney (22%), lung (22%), and head and neck (12%). The median age at discovery of thyroid metastasis was 63 years. The time from diagnosis of primary tumor to metastasis to the thyroid gland was most considerable for renal cell carcinoma (mean 113 mo). Forty-one patients underwent thyroid resection with an average tumor size of 3 cm. Median survival in all patients with metastases was 20 months (range, 1 to 228 mo). Patients who underwent thyroid resection had a median survival of 30 months (range, 3 to 171 mo), whereas survival in patients without thyroid surgery was 12 months (range, 1 to 228 mo, log-rank test P=0.09). CONCLUSIONS: Our experience over the last 30 years confirms that FNA remains a sensitive and specific method to detect metastases to the thyroid. In any patient with a history of a malignancy, a new thyroid mass should be promptly evaluated for recurrent malignancy as early diagnosis and surgical resection resulted in a nonstatistically significant increased median survival.

Abstract Purpose: Transcriptomic profiling can shed light on the biology of small-cell bladder cancer (SCBC), nominating biomarkers, and novel therapeutic targets. Experimental Design: Sixty-three patients with SCBC had small-cell histology confirmed and quantified by a genitourinary pathologist. Gene expression profiling was performed for 39 primary tumor samples, 1 metastatic sample, and 6 adjacent normal urothelium samples (46 total) from the same cohort. Protein levels of differentially expressed therapeutic targets, DLL3 and PDL1, and also CD56 and ASCL1, were confirmed by IHC. A SCBC PDX model was utilized to assess in vivo efficacy of DLL3-targeting antibody–drug conjugate (ADC). Results: Unsupervised hierarchical clustering of 46 samples produced 4 clusters that correlated with clinical phenotypes. Patients whose tumors had the most “normal-like” pattern of gene expression had longer overall survival (OS) compared with the other 3 clusters while patients with the most “metastasis-like” pattern had the shortest OS (P = 0.047). Expression of DLL3, PDL1, ASCL1, and CD56 was confirmed by IHC in 68%, 30%, 52%, and 81% of tissue samples, respectively. In a multivariate analysis, DLL3 protein expression on >10% and CD56 expression on >30% of tumor cells were both prognostic of shorter OS (P = 0.03 each). A DLL3-targeting ADC showed durable antitumor efficacy in a SCBC PDX model. Conclusions: Gene expression patterns in SCBC are associated with distinct clinical phenotypes ranging from more indolent to aggressive disease. Overexpression of DLL3 mRNA and protein is common in SCBC and correlates with shorter OS. A DLL3-targeted ADC demonstrated in vivo efficacy superior to chemotherapy in a PDX model of SCBC.

Tumor necrosis has been shown to be an independent predictor of adverse outcome in renal cell carcinoma. A modification of the International Society of Urological Pathology (ISUP) grading system for renal cell carcinomas has recently been proposed, which incorporates the presence of tumor necrosis into grade. The investigators proposing this system found that necrosis added significant prognostic information to ISUP grade. We attempted to describe our experience with the effect of tumor necrosis in relationship to nuclear grade by reviewing the slides from a large consecutive series of localized clear cell renal cell carcinomas from our institution and obtaining long-term clinical follow-up information (overall survival). Of the 842 clear cell renal cell carcinomas reviewed, 265 (31.5%) were ISUP grade 1 or 2, 437 (51.9%) were ISUP grade 3, and 140 (16.6%) were ISUP grade 4. Tumor necrosis was present in 177 (21%) cases. Five hundred and forty-seven (64.9%) cases were stage pT1, 83 (9.9%) were stage pT2, 193 (22.9%) were stage pT3a, and 19 (2.3%) were pT3b or higher. Median follow-up was 73.2 months (range 0.12 to 273.6), and 310 (36.8%) patients died. On univariable analysis, there was no significant difference in outcome for tumors of ISUP grades 1 to 3. After adjustment for age, tumor stage, and tumor size, ISUP grade 4 and necrosis were significant predictors of overall survival on multivariable analysis. When the recently proposed modified grading system incorporating tumor necrosis was applied to our data, there was no significant difference in overall survival between patients with modified grade 1 tumors and those with modified grade 2 tumors (P=0.31); however, there was a statistically significant difference between patients with modified grade 1 or 2 tumors and those with modified grade 3 tumors (P=0.04),and a substantial difference in outcome between those with modified grade 3 and modified grade 4 tumors (P<0.001). When a recursive partitioning approach was applied to our data, patients of a given ISUP grade could be further prognostically separated according to the presence or absence of necrosis and could be divided into 3 statistically significant prognostic groups: (1) non-necrotic ISUP grade 1 to 3 tumors, (2) ISUP grade 1 to 3 tumors with necrosis and ISUP grade 4 tumors with <10% necrosis, and (3) ISUP grade 4 tumors with >10% necrosis. In conclusion, our study shows that tumor necrosis adds additional prognostic information to ISUP grade and that quantification of necrosis can further stratify patients with ISUP grade 4 tumors.