In-Depth Comparison of Genetic Variants Demonstrates a Close Relationship Between Invasive and Intraductal Components of Prostate Cancer.

Intraductal carcinoma (IDC) of the prostate is often associated with concurrent high-grade invasive prostate cancer (PCa) and poor clinical outcomes. In this context, IDC is thought to represent the retrograde spread of invasive prostatic adenocarcinoma into the acini and ducts. Prior studies have demonstrated a concordance of PTEN loss and genomic instability between the IDC and high-grade invasive components of PCa, but larger genomic association studies to solidify our understanding of the relationship between these 2 lesions are lacking. Here, we evaluate the genomic relationship between duct-confined (high-grade prostatic intraepithelial neoplasia and IDC) and invasive components of high-grade PCa using genetic variants generated by whole exome sequencing. High-grade prostatic intraepithelial neoplasia and IDC were laser-microdissected, and PCa and nonneoplastic tissue was manually dissected from 12 radical prostatectomies. A targeted next-generation sequencing panel was used to identify disease-relevant variants. Additionally, the degree of overlap between adjacent lesions was determined by comparing exome-wide variants detected using whole exome sequencing data. Our results demonstrate that IDC and invasive high-grade PCa components show common genetic variants and copy number alterations. Hierarchical clustering of genome-wide variants suggests that in these tumors, IDC is more closely related to the high-grade invasive components of the tumor compared with high-grade prostatic intraepithelial neoplasia. In conclusion, this study reinforces the concept that, in the context of high-grade PCa, IDC likely represents a late event associated with tumor progression.

Uncommon molecular alterations in follicular-derived thyroid carcinoma: A single institution study.

Thyroid carcinomas are the most common endocrine malignancy and commonly have alterations in the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI3K)/AKT signaling pathways in well-differentiated tumors. Alternative molecular alterations driving thyroid carcinomas have been identified rarely in the literature and are more likely to occur in poorly differentiated or anaplastic cases. In this study, uncommon genetic alterations such as MLH1, MSH2, NSD3::NUTM1, RET::SPECC1L, and G3BP2::FGFR2 were identified in patients with papillary thyroid carcinoma, poorly differentiated thyroid carcinoma, and differentiated high-grade thyroid carcinoma. Most of these tumors demonstrated an aggressive biological behavior. Atypical driver mutations in thyroid carcinomas can occur in patients with cancer predisposition syndromes as demonstrated by an NTRK1::TPM3 fusion in a patient with Li Fraumeni syndrome. In these settings of more aggressive disease, molecular testing targeting actionable fusions and mutations is important. As demonstrated in our case cohort, 100% of cases diagnosed as high-grade follicular-derived thyroid carcinoma had a mutation or fusion that is associated with worse prognosis, has a germline syndrome association requiring further work up, or an actionable mutation. This high yield seen in this cohort for molecular testing in patients with high-grade follicular-derived thyroid carcinoma suggests more routine molecular testing in this population would be a beneficial clinical practice.

CSF3R mutated myeloid neoplasms: Beyond chronic neutrophilic leukemia.

CSF3R activating mutation is a genetic hallmark of chronic neutrophilic leukemia (CNL), and is also present in a subset of atypical chronic myeloid leukemia (aCML), but infrequent in other myeloid neoplasms. However, the occurrence of CSF3R mutations in various myeloid neoplasms is not well studied. Here we evaluate the spectrum of CSF3R mutations and the clinicopathologic features of CSF3R mutated myeloid neoplasms. We retrospectively identified CSF3R mutations in a variety of myeloid neoplasms: two CNL, three atypical chronic myeloid leukemia (aCML), nine acute myeloid leukemia (AML), one chronic myelomonocytic leukemia, and one myeloproliferative neoplasm. The prototypic T618I mutation was found in 50% of cases: CNL (2/2), aCML (2/3) and AML (4/9). We observed a new recurrent CSF3R mutation Q776* in 25% of cases, and a potential-germline mutation in a 20-year-old patient. Co-occurring mutations were often in epigenetic modifier and spliceosome. IDH/RUNX1 and tumor suppressor mutations were frequent in AML but absent in CNL/aCML. All CNL/aCML patients succumbed within 2-years of diagnosis. We demonstrate that CSF3R mutations are not restricted to CNL. CNL and aCML show similar clinicopathologic and molecular features, suggesting that CNL may be best classified as myelodysplastic/myeloproliferative neoplasm rather than myeloproliferative neoplasm.

Utilization of cytologic cell blocks for targeted sequencing of solid tumors.

BACKGROUND: Targeted sequencing of cytologic samples has significantly increased in recent years. With increasing numbers of clinical trials for variant specific therapeutics, validating a comprehensive assay for cytologic samples has become clinically important. AIM: For this study, a retrospective review of cytologic cell blocks from fine needle aspirations and fluid specimens was performed. METHODS: Two hundred twenty six total cases of solid tumor malignancies were identified, of which 120 cases and 20 lymph node negative controls were sequenced for the Oncomine Comprehensive Assay. Cytology and surgical specimen correlation was performed in a subset of cases. Statistical analysis to determine variant concordance was performed. RESULTS: Within the 117 cases sequenced, a total of 347 pathogenic variants were detected. Of the 117 cases, 32 cases (27.4%) would qualify for FDA approved targeted therapy according to the current guidelines, and an additional 23 cases (19.7%) would qualify for clinical trial based on pathogenic variants detected. DISCUSSION: With over 27% of cases in our cohort qualifying for some form of targeted therapy, our study shows the importance of providing comprehensive molecular diagnostic options. Despite only half of the cytology cases in the review period having enough material to be sequenced, overall approximately 27% of patients in this cohort would have benefitted from this service.

Clear cell chondrosarcoma: a review of clinicopathologic characteristics, differential diagnoses, and patient management.

Clear cell chondrosarcoma (CCC), an extremely rare primary bone tumor, is currently classified by the World Health Organization as a low-grade malignant cartilaginous neoplasm. Clinically, CCC occurs primarily in males with a peak incidence in the third to fifth decades of life, and occasionally, it presents in skeletally immature patients. Unlike conventional chondrosarcoma, CCC has a predilection for the epiphysis of long bones and often displays radiologic features reminiscent of chondroblastoma. The recommended treatment is wide operative resection. CCC has a local recurrence rate of approximately 30%, and nearly 20% cases metastasize mainly to bone and lung often a decade after surgical intervention. Incomplete excision or curettage is associated with a high rate of recurrence. Histologically, the process is characterized by infiltrative lobules and sheets of round to oval cells with abundant cleared cytoplasm and well-defined cell borders associated with trabecula of osteoid and woven bone, scattered osteoclasts, and foci of conventional low-grade chondrosarcoma in about one-half of cases. Correlation with clinical and radiologic characteristics, such as epiphyseal location and young patient age, assists in establishing a correct diagnosis. Pathologic diagnosis of CCC is complicated by the low diagnostic accuracy of core needle biopsy, overlapping histologic features with other matrix-rich primary bone tumors, and a lack of a specific immunohistochemical and molecular profile. DNA methylation-based profiling classifier (sarcoma classifier) is one recent technologic advancement that may help to confirm the histopathological diagnosis of CCC or indicate the need for thorough reassessment in cases where results contradict previous conventional findings.

Variant allelic frequencies of driver mutations can identify gliomas with potentially false-negative MGMT promoter methylation results.

MGMT promoter methylation testing is required for prognosis and predicting temozolomide response in gliomas. Accurate results depend on sufficient tumor cellularity, but histologic estimates of cellularity are subjective. We sought to determine whether driver mutation variant allelic frequency (VAF) could serve as a more objective metric for cellularity and identify possible false-negative MGMT samples. Among 691 adult-type diffuse gliomas, MGMT promoter methylation was assessed by pyrosequencing (N = 445) or DNA methylation array (N = 246); VAFs of TERT and IDH driver mutations were assessed by next generation sequencing. MGMT results were analyzed in relation to VAF. By pyrosequencing, 56% of all gliomas with driver mutation VAF ≥ 0.325 had MGMT promoter methylation, versus only 37% with VAF < 0.325 (p < 0.0001). The mean MGMT promoter pyrosequencing score was 19.3% for samples with VAF VAF ≥ 0.325, versus 12.7% for samples with VAF < 0.325 (p < 0.0001). Optimal VAF cutoffs differed among glioma subtypes (IDH wildtype glioblastoma: 0.12-0.18, IDH mutant astrocytoma: ~0.33, IDH mutant and 1p/19q co-deleted oligodendroglioma: 0.3-0.4). Methylation array was more sensitive for MGMT promoter methylation at lower VAFs than pyrosequencing. Microscopic examination tended to overestimate tumor cellularity when VAF was low. Re-testing low-VAF cases with methylation array and droplet digital PCR (ddPCR) confirmed that a subset of them had originally been false-negative. We conclude that driver mutation VAF is a useful quality assurance metric when evaluating MGMT promoter methylation tests, as it can help identify possible false-negative cases.

Validation Study of a Direct Real-Time PCR Protocol for Detection of Monkeypox Virus.

Monkeypox has recently been described as a public health emergency of international concern by the World Health Organization and a public health emergency by the United States. If the outbreak continues to grow, rapid scalability of laboratory testing will be imperative. During the early days of the coronavirus disease 2019 (COVID-19) pandemic, laboratories improved the scalability of testing by using a direct-to-PCR approach. To improve the scalability of monkeypox testing, a direct real-time PCR protocol for the detection of monkeypox virus was validated. The assay retains the sensitivity and accuracy of the indirect assay while eliminating the need for nucleic acid extraction kits, reducing laboratory technologist time per sample and decreasing exposure to an infectious agent. The direct method will make it easier for laboratories across the world to rapidly develop, validate, and scale testing for monkeypox virus.

Deciphering intratumor heterogeneity in clear cell renal cell carcinoma utilizing clinicopathologic and molecular platforms.

Clear cell renal cell carcinoma (CCRCC) is a common renal malignancy known for its lethality and chromosome 3p aberrancies associated with loss of VHL. It has been shown that additional prognostic molecular markers exist in other transcriptional modifiers such as BAP1 and SETD2. Molecular heterogeneity has been described between primary and metastatic sites as well as genetic diversity in spatial tumor analysis; however, morphologic and proteogenomic heterogeneity information is lacking. We assessed 77 nephrectomy specimens with a diagnosis of CCRCC for morphologic architectural patterns including nodular growth patterns and variations in WHO/ISUP grade. Evaluation of highly heterogeneous areas with immunohistochemical (IHC) staining for BAP1, UCHL1, SETD2, and CAIX was performed and correlated with morphologic and histology data. Ultimately, high variability in the morphologic and histological findings matched the complexity of the IHC findings. Alterations in expression of CAIX and UCHL1 correlated with alterations in transcriptional regulators BAP1 and SETD2 within the tumor. High-grade morphology, such as eosinophilia, were areas enriched for alteration of biomarker expression. This highly complex data set of morphologic and biomarker characteristics highlights the heterogeneity of morphology amongst high-grade CCRCC tumors.

Next generation sequencing of cervical high grade dysplasia and invasive squamous cell carcinoma: A case study.

Cervical cancer continues to be a prevalent diagnosis among gynecologic pathology despite widespread screening methods and known pathogenesis by human papilloma virus. We describe a patient who underwent next generation sequencing (NGS) of her high grade squamous dysplasia (HG-SIL) as well as the invasive component of her cervical cancer. This tumor showed an amplification of PIK3CA in the invasive carcinoma in addition to a common E542K mutation both in dysplastic and invasive carcinoma. The dysplasia also showed a novel PCNX (e1) - RAD51B (e8) fusion suggesting potentially new mechanisms of pathogenesis in cervical squamous cell carcinoma.

Presentation of a diagnostically challenging case of chronic eosinophilic leukemia with marrow dysplasia and ringed sideroblasts.

Chronic eosinophilic leukemia, not otherwise specified can be challenging to differentiate from hypereosinophilic syndrome and myelodysplastic syndromes with elevated eosinophilia. We present a diagnostically challenging case of chronic eosinophilic leukemia, not otherwise specified that initially seemed like a myelodysplastic syndrome but progressed to eosinophilic tissue infiltration and overt eosinophilic dyspoiesis. In addition, we discuss the morphologic and molecular findings that can overlap among these entities that made the diagnosis difficult in the case presented.

Thrombocytopenia and Predisposition to Acute Myeloid Leukemia due to Mosaic Ring 21 with Loss of RUNX1: Cytogenetic and Molecular Characterization.

Familial platelet disorder with predisposition to acute myeloid leukemia (FPD/AML) has been well documented in the literature and is a new entity within the latest revised edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (OMIM). The disorder arises due to mutations within the RUNX1 gene in chromosome 21; mutations within the Runt-binding domain are the most commonly encountered anomalies that cause decreased platelet count and function. Rare cases of haploinsufficiency have also been shown to cause this disorder. Here, we describe a 12-year-old female with mosaicism for a ring chromosome 21 and monosomy 21 who was born with thrombocytopenia which is now explained by loss of the RUNX1 gene resulting in FPD/AML. We also comment on the structure of the ring and the mechanism of its formation.