Bone marrow clonal hematopoiesis is highly prevalent in blastic plasmacytoid dendritic cell neoplasm and frequently sharing a clonal origin in elderly patients.

Myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) are reported in up to 20% patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN), where a shared clonal origin is shown in individual case studies. In this study, we performed targeted next generating sequencing on multiple bone marrow (BM), skin or sorted cells from 51 BPDCN patients (68.7 years,14.4-84.7), and detected mutations in BM hematopoietic cells in 65% (30/46) and BPDCN in 100% (27/27), both components showing similar high frequencies of TET2 (60% versus 58%) and ASXL1 (33% versus 40%). Of 24 patients with paired mutation data, 13(54%) had shared mutations, with TET2(77%), ASXL1(37%) and ZRSR2(22%) the most commonly shared, and NRAS the most gained mutation in BPDCN(9/24, 38%). Karyotypic abnormalities were detected in 19/29(66%) BPDCN but only in 1/49 BM hematopoietic cells, providing additional evidence of clonal evolution. BM clonal hematopoiesis (CH) was associated with an older age (p < 0.001), being confounding factors in multivariate analysis; whereas <10% BM BPDCN infiltrate and stem cell transplant were associated with favorable outcomes. This study is the first to report a high prevalence of BM CH in BPDCN patients beyond an associated diagnosis of MDS/CMML, and demonstrates a frequent clonal relationship in elderly, findings contributing to the understanding of BPDCN clonal origin.

Determination of immunophenotypic aberrancies provides better assessment of peripheral blood involvement by mycosis fungoides/Sézary syndrome than quantification of CD26- or CD7- CD4+ T-cells.

BACKGROUND: Blood involvement by mycosis fungoides (MF)/Sézary syndrome (SS) influences prognosis and therapeutic decisions. MF/SS blood stage is currently determined by absolute CD4 + CD26- or CD4 + CD7-cell counts, which quantification method may overestimate MF/SS by including CD26- or CD7- normal CD4+ T-cells, or underestimate disease burden when MF/SS cells show incomplete loss of CD26 and/or CD7. Recently, through the standardization effort led by the International Clinical Cytometry Society (ICCS), recommendation was made to quantify MF/SS by enumerating immunophenotypically aberrant CD4+ T-cells, rather than CD26- or CD7- in isolation. METHODS: We compared these two quantitation methods in 309 MF/SS patients who had blood samples analyzed by flow cytometry immunophenotyping (FCI) over a 1-year period. RESULTS: Using the European Organization of Research and Treatment of Cancer (EORTC)/International Society for Cutaneous Lymphomas (ISCL) criteria, 221 (71.5%) patients had a blood stage corresponding to B0, 57 (18.4%) to B1, and 31 (10%) to B2. By FCI analysis, a total of 62 patients (20.0%) were found positive for MF/SS. Among EORTC B0 patients, 11/221 (5%) were positive by FCI (false negatives), and among EORTC Stage B1 patients, 35/57 (61%) were negative by FCI (false positives). Regarding patients positive for MF/SS cells by FCI, there was an overall excellent correlation (r = .999, p < .001) between the EORTC/ISCL method and FCI method; however, four (6.5%) patients would have an altered B stage between B0 and B1. CONCLUSION: The MF/SS cell quantification method using immunophenotypic aberrancies, as recommended by the ICCS, allows to distinguish MF/SS cells from background benign T-cells and enables for more accurate staging, especially among patients currently being considered to have B0 and B1 stage diseases.

Merkel cell carcinoma mimicking transformed chronic lymphocytic leukemia/small lymphocytic lymphoma.

Although MCC has been reported in patients with CLL/SLL, it is extremely rare to observe these two within the same tumor. MCC's positivity for PAX5 and TdT may pose a diagnostic challenge by mimicking transformed CLL/SLL. A thorough workup is critical in reaching the correct diagnosis.

Atypical tuberous sclerosis complex presenting as familial renal cell carcinoma with leiomyomatous stroma.

We report an atypical tuberous sclerosis complex (TSC) phenotype presenting as familial multiple renal cell carcinomas (RCCs) with (angio)leiomyomatous stroma (RCCLS) (5/7 familial RCCs) on a background of multiple angiomyolipomas, hypopigmented skin macules, and absence of neurological anomalies. In the index case and three relatives, germline genetic testing identified a heterozygous TSC2 missense pathogenic variant [c.2714 G > A, (p.Arg905Gln)], a rare TSC-associated alteration which has previously been associated with a milder TSC phenotype. Whole-exome sequencing of five RCCs from the index case and one RCC from his mother demonstrated either unique tumour-specific deleterious second hits in TSC2 or significant allelic imbalance at the TSC2 gene locus (5/6 RCCs). This study confirms the key tumourigenic role of tumour-specific TSC2 second hits in TSC-associated RCCs and supports the notion that RCCLS may be strongly related to abnormalities of the mTOR pathway.

Deep Sequencing Reveals Spatially Distributed Distinct Hot Spot Mutations in DICER1-Related Multinodular Goiter.

CONTEXT: Nontoxic multinodular goiter (MNG) occurs frequently, but its genetic etiology is not well established. Familial MNG and MNG occurring with ovarian Sertoli-Leydig cell tumor are associated with germline DICER1 mutations. We recently identified second somatic DICER1 ribonuclease (RNase) IIIb mutations in two MNGs. OBJECTIVE: The objective of the study was to investigate the occurrence of somatic DICER1 mutations and mutational clonality in MNG. PATIENTS: MNGs from 15 patients (10 with and five without germline DICER1 mutations) were selected based on tissue availability. DESIGN: Core biopsies/scrapings (n = 70) were obtained, sampling areas of follicular hyperplasia, hyperplasia within colloid pools, unremarkable thyroid parenchyma, and areas of thyroid parenchyma, not classified. After capture with a Fluidigm access array, the coding sequence of DICER1 was deep sequenced using DNA from each core/scraping. RESULTS: All germline DICER1-mutated cases were found to harbor at least one RNase III mutation. Specifically, we identified 12 individually distinct DICER1 RNase IIIb hot spot mutations in 32 of the follicular hyperplasia or hyperplasia within colloid pools cores/scrapings. These mutations are predicted to affect the metal-ion binding residues at positions p.Glu1705, p.Asp1709, p.Gly1809, p.Asp1810, and p.Glu1813. Somatic RNase IIIb mutations were identified in the 10 DICER1 germline mutated MNGs as follows: two cases contained one somatic mutation, five cases contained two mutations, and three cases contained three distinct somatic hot spot mutations. No RNase IIIb mutations were identified in the MNGs from individuals without germline DICER1 mutations. CONCLUSIONS: This study demonstrates that nodules within MNG occurring in DICER1 syndrome are associated with spatially distributed somatic DICER1 RNase IIIb mutations.

Germline and Somatic DICER1 Mutations in a Well-Differentiated Fetal Adenocarcinoma of the Lung.

Germ-line DICER1 mutations predispose to a distinctive tumour predisposition syndrome, the DICER1 syndrome, which is associated with a spectrum of rare mainly childhood-onset tumours. In 2014, a case of well-differentiated fetal adenocarcinoma of the lung (WDFA) was reported in a 16-year-old germ-line DICER1 mutation carrier. Here we report our finding of a characteristic somatic DICER1 RNase IIIb c.5127T>A (p.Asp1709Glu) missense mutation within the WDFA, confirmed using laser capture microscopy. The child has a personal history consistent with the DICER1 syndrome: she developed a multinodular goitre at age 14 years and an ovarian Sertoli-Leydig cell tumour at age 16 years, each of which were found to harbour a somatic DICER1 RNase IIIb missense mutation. The identification of two DICER1 "hits" in the WDFA strongly suggests that WDFA is a rare, previously-unrecognised manifestation of DICER1 syndrome.

Biallelic NTHL1 Mutations in a Woman with Multiple Primary Tumors.

A patient is described with multiple cancers and compound heterozygous mutations in NTHL1, a recently described polyposis gene. The involvement of a second causative mutation is reported.

Pleural ultrasound as an adjunct to physical examination in the preoperative evaluation of lung cancer patients.

OBJECTIVES: Preoperative evaluation of patients with suspected or confirmed lung cancer consists of clinical and radiological staging. Malignant pleural effusion is a poor prognosticator in non-small-cell lung cancer. Pleural ultrasound (PU) allows for the assessment of pleural effusion, providing real-time guidance for its aspiration and cytological analysis. Pleural Ultrasonography in Lung Cancer (PULC) as an adjunct to physical examination has the potential to improve preoperative staging of non-small-cell lung cancer during first surgical encounter by allowing the evaluation of previously unassessed pleural effusion. METHODS: This study consisted of a prospective trial of surgeon-performed PU in the preoperative evaluation of lung cancer patients. All patients evaluated in the thoracic surgery clinic with the new or presumed diagnosis of lung cancer were eligible. A portable ultrasound machine was used to evaluate pleural fluid in the bilateral costophrenic sulci with pleural fluid aspiration for cytological analysis. RESULTS: Forty-five patients were prospectively enrolled over a 3-month period. Thirteen patients had ultrasound evidence of a pleural effusion, of which 3 were significant enough for aspiration. Cytological analysis of these effusions yielded malignant cells in 1 patient. Positive PULC evaluation led to a change in clinical staging (M0 to M1a) in 10 patients and a change in pathological staging (pleural fluid cytology positive) in 1 patient. The time required for PULC examination was 15 ± 7 min. There were no complications related to the procedures. CONCLUSIONS: Preoperative pleural ultrasonography is a rapid and effective way to improve precision of staging in patients with lung cancer. More precise staging may allow for more appropriate testing, patient prognostication and operative planning.

Prospective trial evaluating sonography after thoracic surgery in postoperative care and decision making.

OBJECTIVE: Following thoracic surgery, daily chest X-rays (CXRs) are performed to assess patient evolution and to make decisions regarding chest tube removal and patient discharge. Sonography after thoracic surgery (SATS) has the potential to be an effective, convenient, inexpensive and easy to learn tool in the post-operative management of thoracic surgery patients. We hypothesized that SATS could alleviate the need for repetitive CXRs, thus reducing the related risks, costs and inconvenience. METHODS: This study consisted of a prospective cohort trial. All patients scheduled to undergo thoracic surgery at a single academic medical centre were eligible. Post-operative bedside pleural ultrasound was performed whenever a CXR was ordered by the treating team. Investigators specifically assessed patients with the goals of identifying pleural effusions and pneumothoraces. Study investigators were blinded to CXR results. SATS findings were compared with CXRs, which were considered the gold standard in routine post-operative pleural space evaluation. RESULTS: One hundred and twenty patients were prospectively enrolled over a 5.5-month period. Three hundred and fifty-two ultrasound examinations were performed (mean = 3.0 ± 2.4 exams per patient). The time interval between the ultrasound and the comparative CXR was 166 ± 149 min. The mean time required to perform SATS was 11 ± 6 min per exam. In the detection of pleural effusion, SATS yielded a sensitivity of 83.1% and a specificity of 59.3%. In the detection of pneumothoraces, a sensitivity of 21.2% and a specificity of 94.7% were obtained. CONCLUSIONS: Post-operative ultrasound may alleviate the need to perform routine CXR in patients with a previously ruled out pneumothorax. SATS used selectively may be able to reduce the number of routine CXRs performed; however, it does not have high enough accuracy to replace CXRs.