Pathologist Computer-Aided Diagnostic Scoring of Tumor Cell Fraction: A Swiss National Study.

Tumor cell fraction (TCF) estimation is a common clinical task with well-established large interobserver variability. It thus provides an ideal test bed to evaluate potential impacts of employing a tumor cell fraction computer-aided diagnostic (TCFCAD) tool to support pathologists' evaluation. During a National Slide Seminar event, pathologists (n = 69) were asked to visually estimate TCF in 10 regions of interest (ROIs) from hematoxylin and eosin colorectal cancer images intentionally curated for diverse tissue compositions, cellularity, and stain intensities. Next, they re-evaluated the same ROIs while being provided a TCFCAD-created overlay highlighting predicted tumor vs nontumor cells, together with the corresponding TCF percentage. Participants also reported confidence levels in their assessments using a 5-tier scale, indicating no confidence to high confidence, respectively. The TCF ground truth (GT) was defined by manual cell-counting by experts. When assisted, interobserver variability significantly decreased, showing estimates converging to the GT. This improvement remained even when TCFCAD predictions deviated slightly from the GT. The standard deviation (SD) of the estimated TCF to the GT across ROIs was 9.9% vs 5.8% with TCFCAD (P < .0001). The intraclass correlation coefficient increased from 0.8 to 0.93 (95% CI, 0.65-0.93 vs 0.86-0.98), and pathologists stated feeling more confident when aided (3.67 ± 0.81 vs 4.17 ± 0.82 with the computer-aided diagnostic [CAD] tool). TCFCAD estimation support demonstrated improved scoring accuracy, interpathologist agreement, and scoring confidence. Interestingly, pathologists also expressed more willingness to use such a CAD tool at the end of the survey, highlighting the importance of training/education to increase adoption of CAD systems.

Deciphering the genetic landscape of pulmonary lymphomas.

Pulmonary lymphoid malignancies comprise various entities, 80% of them are pulmonary marginal zone B-cell lymphomas (PMZL). So far, little is known about point mutations in primary pulmonary lymphomas. We characterized the genetic landscape of primary pulmonary lymphomas using a customized high-throughput sequencing gene panel covering 146 genes. Our cohort consisted of 28 PMZL, 14 primary diffuse large B-cell lymphomas (DLBCL) of the lung, 7 lymphomatoid granulomatoses (LyG), 5 mature small B-cell lymphomas and 16 cases of reactive lymphoid lesions. Mutations were detected in 22/28 evaluable PMZL (median 2 mutation/case); 14/14 DLBCL (median 3 mutations/case) and 4/7 LyG (1 mutation/case). PMZL showed higher prevalence for mutations in chromatin modifier-encoding genes (44% of mutant genes), while mutations in genes related to the NF-κB pathway were less common (24% of observed mutations). There was little overlap between mutations in PMZL and DLBCL. MALT1 rearrangements were more prevalent in PMZL than BCL10 aberrations, and both were absent in DLBCL. LyG were devoid of gene mutations associated with immune escape. The mutational landscape of PMZL differs from that of extranodal MZL of other locations and also from splenic MZL. Their landscape resembles more that of nodal MZL, which also show a predominance of mutations of chromatin modifiers. The different mutational composition of pulmonary DLBCL compared to PMZL suggests that the former probably do not present transformations. DLBCL bear more mutations/case and immune escape gene mutations compared to LyG, suggesting that EBV infection in LyG may substitute for mutations.

Diagnosis of Fetal Posterior Fossa Malformations in High-Risk Pregnancies at 12-14 Gestational Weeks by Transvaginal Ultrasound Examination.

OBJECTIVE: To demonstrate sonographic detectable abnormalities of the posterior fossa in fetuses with a crown-rump length of 45-84 mm in high-risk pregnancies. METHODS: This was a prospective, observational study including 47 fetuses with known outcome, whose mothers attended our centers for first trimester tests and showed an abnormal first trimester ultrasound scan. In these fetuses, we examined transvaginal acquired three-dimensional volume blocks for abnormalities of the fetal posterior fossa. In these fetuses, the measurements of the cerebellar vermis (VE) and of the anterior membranous area (AMA) were compared with published reference ranges. RESULTS: There were 8 fetuses with a ver-mian length below the 5th centile. In 5 of these fetuses, the AMA was also elongated and in 4 of these fetuses, pathology was confirmed. One case with a normal vermian length and normal AMA had a hypoplastic VE later on in the confirmatory test. CONCLUSION: Pathology of the posterior fossa can be directly diagnosed by assessing the VE and the AMA at the first trimester scan by examining transvaginal acquired volume blocks.

Intrasinusoidal bone marrow involvement in mantle cell lymphoma: a case series with review of the main differential diagnoses.

Intrasinusoidal bone marrow involvement is an infrequent histological pattern observed in a limited number of B and T cell lymphomas. Mantle cell lymphoma is a biologically and prognostically heterogeneous B cell lymphoma that frequently involves the bone marrow, with interstitial, nodular-paratrabecular, or diffuse patterns. Intrasinusoidal bone marrow involvement has been described only anecdotally in this lymphoma. Here, we describe the clinical, histopathological, and molecular features of four patients diagnosed with advanced-stage mantle cell lymphoma, showing intrasinusoidal bone marrow involvement, and other peculiar immunophenotypical features. As similar cases may represent a relevant issue in bone marrow diagnostic histopathology, we also reviewed the literature to discuss differential diagnoses of B and T cell lymphomas with intrasinusoidal bone marrow involvement.

Testicular Rosai-Dorfman disease clonally related to CMML - Case report and literature review.

BACKGROUND: Rosai-Dorfman disease (RDD), a rare form of non-Langerhans cell histiocytosis with heterogenous clinical features, arises from precursor cells that give rise to cells of the histiocytic and monocytic lineages. An association with hematological neoplasms has been reported. Testicular RDD is rarely described, with only 9 reported cases in the literature. Genetic data to assess clonal relationships between RDD and other hematological neoplasms remain scarce. We describe an instance of testicular RDD against a background of chronic myelomonocytic leukemia (CMML), with genetic studies in both neoplasms. CASE PRESENTATION: A 72-year-old patient with a history of CMML sought evaluation of growing bilateral testicular nodules. Solitary testicular lymphoma was suspected; orchidectomy was performed. The diagnosis of testicular RDD was established morphologically and confirmed immunohistochemically. Molecular analysis of testicular lesions and of archived patient bone marrow revealed the KRAS variant c 0.35 G>A / p.G12D in both, suggesting a clonal relationship. CONCLUSION: These observations support classifying RDD as a neoplasm that can be clonally related to myeloid neoplasms.

H3K27m3 overexpression as a new, BCL2 independent diagnostic tool in follicular and cutaneous follicle center lymphomas.

Approximately 15% of follicular lymphomas (FL) lack overexpression of BCL2 and the underlying translocation t(14;18). These cases can be diagnostically challenging, especially regarding follicular hyperplasia (FH). In a subset of FL, mutations in genes encoding for epigenetic modifiers, such as the histone-lysine N-methyltransferase EZH2 (enhancer of zeste homolog 2), were found, which might be used diagnostically. These molecular alterations can lead to an increased tri-methylation of histone H3 at position lysine 27 (H3K27m3) that, in turn, can be visualized immunohistochemically. The aim of this study was to analyze the expression of H3K27m3 in FL, primary cutaneous follicle center lymphomas (PCFCL), and pediatric-type FL (PTFL) in order to investigate its value in the differential diagnosis to FH and other B cell lymphomas and to correlate it to BCL2 expression and the presence of t(14;18). Additionally, the mutational profile of selected cases was considered to address H3K27m3's potential use as a surrogate parameter for mutations in genes encoding for epigenetic modifiers. Eighty-nine percent of FL and 100% of PCFCL cases overexpressed H3K27m3, independently of BCL2, EZH2, and the presence of mutations. In contrast, 95% of FH and 100% of PTFL cases lacked H3K27m3 overexpression. Other B cell lymphomas considered for differential diagnosis also showed overexpression of H3K27m3 in the majority of cases. In summary, overexpression of H3K27m3 can serve as a new, BCL2 independent marker in the differential diagnosis of FL and PCFCL, but not PTFL, to FH, while being not of help in the differential diagnosis of FL to other B cell lymphomas.

Idiopathic Multicentric Castleman Disease Occurring Shortly after mRNA SARS-CoV-2 Vaccine.

Idiopathic Multicentric Castleman Disease (iMCD) is a potentially life-threatening systemic disease whose complex symptomatology is due to cytokine dysregulation. We, herein, present a case of severe iMCD occurring in a previously healthy young man shortly after mRNA SARS-CoV-2 vaccination, responding to interleukin-6 blockade with siltuximab. Six months after the completion of siltuximab, the patient remained without any signs of iMCD or inflammation, indicating a temporal trigger of the disease. This case not only adds to the potential pathogenetic spectrum of MCD, but also extends the clinical picture of potential but rare adverse events following COVID-19 immunization.

Clinicopathologic Features and Prognostic Impact of Lymph Node Involvement in Patients With Breast Implant-associated Anaplastic Large Cell Lymphoma.

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare T-cell lymphoma that arises around breast implants. Most patients manifest with periprosthetic effusion, whereas a subset of patients develops a tumor mass or lymph node involvement (LNI). The aim of this study is to describe the pathologic features of lymph nodes from patients with BI-ALCL and assess the prognostic impact of LNI. Clinical findings and histopathologic features of lymph nodes were assessed in 70 patients with BI-ALCL. LNI was defined by the histologic demonstration of ALCL in lymph nodes. Fourteen (20%) patients with BI-ALCL had LNI, all lymph nodes involved were regional, the most frequent were axillary (93%). The pattern of involvement was sinusoidal in 13 (92.9%) cases, often associated with perifollicular, interfollicular, and diffuse patterns. Two cases had Hodgkin-like patterns. The 5-year overall survival was 75% for patients with LNI and 97.9% for patients without LNI at presentation (P=0.003). Six of 49 (12.2%) of patients with tumor confined by the capsule had LNI, compared with LNI in 8/21 (38%) patients with tumor beyond the capsule. Most patients with LNI achieved complete remission after various therapeutic approaches. Two of 14 (14.3%) patients with LNI died of disease compared with 0/56 (0%) patients without LNI. Twenty percent of patients with BI-ALCL had LNI by lymphoma, most often in a sinusoidal pattern. We conclude that BI-ALCL beyond capsule is associated with a higher risk of LNI. Involvement of lymph nodes was associated with decreased overall survival. Misdiagnosis as Hodgkin lymphoma is a pitfall.

Combined radiotherapy and razoxane in the treatment of chondrosarcomas and chordomas.

BACKGROUND: Chondrosarcomas and chordomas are reported to have low radio-sensitivity. Therefore, a study was undertaken to explore the radioresponsiveness of these tumours using the sensitising agent razoxane. PATIENTS AND METHODS: Thirteen chondrosarcomas and five chordomas were irradiated with high-energy photons and razoxane in the period from 1984 to 2003. The median tumour dose was 60 Gy in the chondrosarcomas and 63 Gy in chordomas. Razoxane tablets were given at a dose of 125 mg twice daily starting 5 days before the first irradiation. The drug was continued on radiation days. RESULTS: Eight out of the 13 chondrosarcomas had unresectable or recurrent measurable disease. There were one complete and five partial responses, while two tumours remained unchanged (response rate 75%). The median duration of response was 22 months. Three out of four patients without clear surgical margins and one patient with clear margins had locally controlled disease. Overall, local control was achieved in seven out of twelve patients who were not radically resected. All five patients with chordomas survived 5 years and remained locally controlled at that time. Among four measurable tumours, two complete and one partial regression were noted. Razoxane was well tolerated; the dose limiting toxicity was leukopenia. CONCLUSION: Photon irradiation together with razoxane induces major responses in a majority of patients with chondrosarcomas and chordomas. This combination therapy seems to be more effective than photon irradiation alone.

Autosomal dominant Carvajal plus syndrome due to the novel desmoplakin mutation c.1678A > T (p.Ile560Phe).

BACKGROUND: Carvajal syndrome is an autosomal dominant or autosomal recessive disorder, manifesting with dilated cardiomyopathy, woolly hair, and palmoplantar keratoma. Additional manifestations can be occasionally found. Carvajal syndrome may be due to mutations in the desmocollin-2, desmoplakin, or plakophilin-2 gene. METHODS AND RESULTS: We report a family with Carvajal syndrome which additionally presented with hypoacusis, noncompaction, recurrent pharyngeal infections, oligodontia, and recurrent diarrhoea. Father and brother were also affected and had died suddenly, the father despite implantation of a cardioverter defibrillator (ICD). Genetic studies revealed the novel pathogenic mutation c.1678A > T in the desmoplakin gene resulting in the amino acid change Ile to Phe at position 560 in the index case and her brother. The index case underwent ICD implantation recently. CONCLUSION: Phenotypic manifestations of Carvajal syndrome are even broader than so far anticipated, the number of mutations in the desmoplakin gene responsible for Carvajal syndrome is still increasing, and these patients require implantation of an ICD as soon as their diagnosis is established.

Matrix composition of cartilaginous anlagen in achondrogenesis type II (Langer-Saldino).

Skeletal dysplasias represent in vivo models of genetic defects. Achondrogenesis type II (Langer-Saldino), caused by a genetic defect in the major cartilage matrix protein, collagen type II, is a rare and severe skeletal dysplasia. It comprises a severe derangement of the fetal growth plate cartilage with subsequent ossification defects. In this study, we analyzed the matrix composition and cell differentiation pattern in 3 relatives with achondrogenesis type II. Most strikingly we found a strongly reduced collagen type II and moderately reduced aggrecan proteoglycan content in the dysplastic cartilage matrix. Type II collagen is, at least to some extent, replaced by collagens type I III, and VI. Ultrastructural analysis of the dysplastic cartilage matrix demonstrated a distended rER (rough endoplasmic reticulum), which is typical for this condition and most likely related to improper processing and retention of genetically altered type II collagen. Immunostaining for type IIA and X collagens suggest a severe delay in chondrocyte maturation. Thus, the genetic defect in the present cases leads most likely to a severe retention of collagen type II in the rER and, therefore, a strongly reduced collagen deposition and replacement by other interstitial collagens. However, the latter are less efficient in binding aggrecan proteoglycans in the dysplastic cartilage matrix. Additionally, a delay in chondrocyte maturation appears to be important in achondrogenesis type II.

A small prospective study of chordomas treated with radiotherapy and razoxane.

PURPOSE: To evaluate the local effect of conventional photon irradiation in chordomas if the radiosensitizing agent razoxane is added. The rationale for this procedure were improved results previously seen in soft tissue and chondrosarcomas with this combination. PATIENTS AND METHODS: Between 1988 and 1996, five patients with histologically confirmed chordomas of the skull base or the spine (three females, two males) were irradiated with 6- and 25-MeV photons under razoxane medication, one patient was treated with a telecobalt unit. Single doses of 180-200 cGy were given five times a week. The median total tumor dose was 63 Gy (range 54-67 Gy). Concomitantly, the radiosensitizer razoxane was administered at a dose of 125 mg twice daily p.o., median total dose 7.6 g. The drug was started 3-5 days before the first irradiation, and continued until the end of radiotherapy. RESULTS: After a potential median follow-up time of 10 years, three of the five patients are alive and show neither symptoms nor signs of recurrence in CT or MR images. One patient with persistent sacral chordoma died after 8 years from cardiac insufficiency, and another patient died after 6.5 years from a bleeding complication following surgery for recurrence. The patients remained locally controlled for 5, 5.5+, 6.4, 11+, and 13+ years, respectively. Objective tumor regressions were noted in three of four patients with measurable disease. Acute side effects included mucosal reactions, two of five patients developed a leukopenia WHO grade 3 due to razoxane. Serious long-term complications were not observed. CONCLUSIONS: Although the patient series is small, there is an interesting trend in local control and survival. The cases are unselected, and the follow-up time is of considerable duration. The treatment can easily be performed at any institution and is tolerated fairly well.

Neonatal type IV glycogen storage disease associated with "null" mutations in glycogen branching enzyme 1.

The fatal neonatal form of type IV glycogen storage disease (GSD IV) was diagnosed on light and electron microscopy and by analysis of GBE1 , the gene encoding glycogen branching enzyme. We report two novel truncating mutations, as well as the first genomic mutational analysis of GBE1 using denaturing high performance liquid chromatography.