Prostatic adenocarcinoma is the most commonly occurring cancer among men in the United States, second only to skin cancer. Currently, the only definitive method to ascertain the presence of prostatic cancer is by trans-rectal ultrasound (TRUS) directed biopsy. Owing to the poor image quality of ultrasound, the accuracy of TRUS is only 20%-25%. High-resolution magnetic resonance imaging (MRI) has been shown to have a higher accuracy of prostate cancer detection compared to ultrasound. Consequently, several researchers have been exploring the use of high resolution MRI in performing prostate biopsies. Visual detection of prostate cancer, however, continues to be difficult owing to its apparent lack of shape, and the fact that several malignant and benign structures have overlapping intensity and texture characteristics. In this paper, we present a fully automated computer-aided detection (CAD) system for detecting prostatic adenocarcinoma from 4 Tesla ex vivo magnetic resonance (MR) imagery of the prostate. After the acquired MR images have been corrected for background inhomogeneity and nonstandardness, novel three-dimensional (3-D) texture features are extracted from the 3-D MRI scene. A Bayesian classifier then assigns each image voxel a "likelihood" of malignancy for each feature independently. The "likelihood" images generated in this fashion are then combined using an optimally weighted feature combination scheme. Quantitative evaluation was performed by comparing the CAD results with the manually ascertained ground truth for the tumor on the MRI. The tumor labels on the MR slices were determined manually by an expert by visually registering the MR slices with the corresponding regions on the histology slices. We evaluated our CAD system on a total of 33 two-dimensional (2-D) MR slices from five different 3-D MR prostate studies. Five slices from two different glands were used for training. Our feature combination scheme was found to outperform the individual texture features, and also other popularly used feature combination methods, including AdaBoost, ensemble averaging, and majority voting. Further, in several instances our CAD system performed better than the experts in terms of accuracy, the expert segmentations being determined solely from visual inspection of the MRI data. In addition, the intrasystem variability (changes in CAD accuracy with changes in values of system parameters) was significantly lower than the corresponding intraobserver and interobserver variability. CAD performance was found to be very similar for different training sets. Future work will focus on extending the methodology to guide high-resolution MRI-assisted in vivo prostate biopsies.

Sinonasal undifferentiated carcinoma (SNUC) is a high-grade malignancy with limited treatment options and poor outcome. A morphologic spectrum of 47 sinonasal tumors including 17 (36.2%) SNUCs were analyzed at genomic level. Thirty carcinomas (Cohort 1) were subjected to a hybridization exon-capture next-generation sequencing assay (MSK-IMPACT™) to interrogate somatic variants in 279 or 410 cancer-related genes. Seventeen sinonasal tumors (Cohort 2) were examined only for presence of IDH1/2 exon 4 mutations by Sanger sequencing. IDH2 R172 single nucleotide variants were overall detected in 14 (82.4%) SNUCs, in 2 (20%) poorly-differentiated carcinomas with glandular/acinar differentiation, and in one of 2 high-grade neuroendocrine carcinomas, large cell type (HGNEC). No IDH2 mutation was detected in any of 5 olfactory neuroblastomas or in any of 5 SMARCB1–deficient carcinomas. Among 12 IDH2-mutated cases in Cohort 1, 5 (41.7%) harbored co-existing TP53 mutations, 4 (33.3%) CDKN2A/2B loss-of-function alterations, 4 (33.3%) MYC amplification, and 3 (25%) had concurrent SETD2 mutations. AKT1 E17K and KIT D816V hotspot variants were each detected in one IDH2-mutated SNUC. The vast majority of SNUCs and variable proportions of other poorly differentiated sinonasal carcinomas may be amenable to IDH2-targeted therapy.

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We reviewed 17 cases of primary anorectal malignant melanoma. Morphologic features evaluated included junctional change, pigmentation, morphology, and mitotic rate. Immunohistochemical stains were performed for/with S-100 protein, HMB-45, MelanA, tyrosinase, vimentin, KIT, and pankeratin. Morphologic subtypes were as follows: epithelioid, 12 cases; spindle cell, 7 cases; lymphoma-like, 10 cases; and pleomorphic, 6 cases. Pigmentation was present in 9 cases. Junctional change was present in 6 cases. The mitotic rate was 3 or more per high-power field in 8 cases. S-100 protein was present in all cases, HMB-45 stained 16 of 17, MelanA was present in 14 of 15, tyrosinase in 12 of 14, vimentin in 13 of 14, and KIT in 12 of 16. Pankeratin was absent in all cases. The mean length of follow-up was 25.6 months (range, 8-96 months), and the average survival with disease was 32.3 months (range, 8-96). No morphologic or immunohistochemical features were predictive of survival. Anorectal malignant melanoma shows considerable morphologic variability. Immunohistochemical staining is similar to cutaneous melanomas. Expression of KIT was present frequently, including cases with spindle cell morphologic features, in which it may lead to confusion with gastrointestinal stromal tumors.

Intraductal carcinomas (IDCs) of salivary gland are rare neoplasms. Here, we report a case of IDCs harboring TRIM27-RET fusion with mixed low grade and apocrine types. A 79-year-old male presented with slowly-growing left parotid mass for 2.5 years. Histologically, the tumor demonstrated two distinct morphologies; a classic intercalated duct and low grade apocrine component. The intercalated duct component was positive for S100, SOX10 and vimentin, and negative for DOG-1 and HER2. The apocrine component was positive for androgen receptor (AR) and focally positive for HER2. The tumor harbored a TRIM27-RET fusion by FISH, and was negative for ETV6 and PLAG1 rearrangements. This case is unusual in that it displays two true phenotypically distinct components, which has only rarely been reported. This is the first report of intraductal carcinoma with two true phenotypically distinct components composed of low-grade and apocrine types with RET rearrangement and TRIM27-RET fusion.