Revealing RB1 loss in an emerging entity: report of two cases of PRRX1-rearranged mesenchymal tumours.

AIMS: PRRX1-rearranged mesenchymal tumours are a recently identified and rare subgroup of soft tissue neoplasms with distinct morphological features and genetic alterations. This study aims to further investigate the immunohistochemical profile and underlying genetic alterations in these tumours in order to get more insight on their underlying biology and the unique profile of these tumours. METHODS: Two new molecular confirmed cases of PRRX1-rearranged mesenchymal tumours were thoroughly studied with immunohistochemical stainings (RB1, CD34, ALK and pan-TRK), fluorescence in situ hybridisation (FISH) RB1/13q12 and RNA-based next-generation sequencing. RESULTS: Both cases exhibited typical morphological and molecular features, confirming the diagnosis of PRRX1-rearranged mesenchymal tumours. Immunohistochemistry revealed RB1 loss in both cases, which was subsequently confirmed through FISH analysis. Additionally, one case showed focal positivity for CD34, ALK and pan-TRK on immunohistochemistry. CONCLUSIONS: We identified loss of RB1 in two cases of PRRX1-rearranged mesenchymal tumours. This could suggest a potential association with RB1-deficient soft tissue tumours, although further research is necessary. Furthermore, the finding of focal positivity for CD34, ALK and pan-TRK on immunohistochemistry enriches the immunohistochemical profile of these tumours.

Breast implant associated EBV-positive Diffuse Large B-cell lymphoma: an underrecognized entity?

Breast-implant associated (BIA) lymphoma is an infrequent type of cancer occurring in the fluid and fibrous capsule around a textured breast implant. Recently, both the 2022 WHO 5th edition classification of Haematological tumours (WHO HAEM5) and 2022 International Consensus Classification of Mature Lymphoid Neoplasms (22ICC), recognized breast implant-associated Anaplastic Large Cell Lymphoma (BIA-ALCL) as a definitive entity, defined as a mature CD30-positive T-cell lymphoma, confined by a fibrous capsule, in a breast implant setting. Only few B-cell lymphomas have been reported in the literature to be associated with breast implants. Here we report two EBV-positive Diffuse Large B-cell lymphomas (EBV + DLBCL) in relation to a breast implant, both expressing CD30 as well as EBV latency type 3. Both lesions were considered as DLBCL associated with chronic inflammation (CI-DLBCL), but one presented as a 7 cm solid mass, while the other presented as a fibrin-associated DLBCL (FA-DLBCL) in an HIV patient. Clinically, both are in complete remission 6 months or longer after capsulectomy and graft removal, without additional chemotherapy.Such cases, characterized by large CD30-positive cells, can easily be misdiagnosed as BIA-ALCL if the cell of origin is not further established. Therefore, a diagnostic panel including lineage-specific B-and T-cell markers and EBER in situ hybridization is essential to recognize this rare entity, to understand lymphomagenesis, to predict outcome and to define clinical approach.

HRAS-related epidermal nevus syndromes: Expansion of the spectrum with first branchial arch defects.

Epidermal nevus syndrome (ENS) comprises a heterogeneous group of neurocutaneous syndromes associated with the presence of epidermal nevi and variable extracutaneous manifestations. Postzygotic activating HRAS pathogenic variants were previously identified in nevus sebaceous (NS), keratinocytic epidermal nevus (KEN), and different ENS, including Schimmelpenning-Feuerstein-Mims and cutaneous-skeletal-hypophosphatasia syndrome (CSHS). Skeletal involvement in HRAS-related ENS ranges from localized bone dysplasia in association with KEN to fractures and limb deformities in CSHS. We describe the first association of HRAS-related ENS and auricular atresia, thereby expanding the disease spectrum with first branchial arch defects if affected by the mosaic variant. In addition, this report illustrates the first concurrent presence of verrucous EN, NS, and nevus comedonicus (NC), indicating the possibility of mosaic HRAS variation as an underlying cause of NC. Overall, this report extends the pleiotropy of conditions associated with mosaic pathogenic variants in HRAS affecting ectodermal and mesodermal progenitor cells.

Identification of Codon 146 KRAS Variants in Isolated Epidermal Nevus and Multiple Lesions in Oculoectodermal Syndrome: Confirmation of the Phenotypic Continuum of Mosaic RASopathies.

Mosaic RASopathies are a molecularly heterogeneous group of (neuro)cutaneous syndromes with high phenotypical variability. Postzygotic variants in KRAS have been described in oculoectodermal syndrome (OES), encephalocraniocutaneous lipomatosis (ECCL) and epidermal nevus syndrome (ENS). This study confirms the continuum of mosaic neurocutaneous RASopathies showing codon 146 KRAS variants in an individual with OES and, for the first time, in an individual with (isolated) epidermal nevus. The presence of a nevus psiloliparus in individuals with OES indicates that this finding is not specific for ECCL and highlights the phenotypical overlap between ECCL and OES. The presence of the somatic KRAS variant in the nevus psiloliparus resolves the underlying molecular etiology of this fatty-tissue nevus. In addition, this finding refutes the theory of non-allelic twin-spotting as an underlying hypothesis to explain the concurrent presence of two different mosaicisms in one individual. The identification of codon 146 KRAS variants in isolated epidermal nevus introduces a new hot spot for this condition, which is useful for increasing molecular genetic testing using targeted gene sequencing panels.

Stratified Mucin-producing Intraepithelial Lesions of the Cervix: Clinical Diversity of Cases and Literature Review.

BACKGROUND: This report discusses the current literature on both non-invasive and invasive SMILE ((i)SMILE) lesions of the cervix with focus on the pathology and its related clinical diversity in several cases. Currently, the knowledge on (i)SMILE is limited to single case reports and series. As a consequence, consensus guidelines regarding the management are lacking. Although there is overlap with both high grade squamous intra-epithelial lesion (HSIL) and adenocarcinoma in situ (AIS) on immunohistochemical analyses, it is recommended to treat SMILE like AIS and further excision is needed when surgical margins are positive for SMILE on conization. (i)SMILE, should be considered as a rare subtype of adenocarcinoma of the cervix, and should be treated as such. CASE REPORT: We describe a case with a SMILE lesion undergoing a subsequent robotic hysterectomy after conization and two cases with iSMILE: one case with an early FIGO-stage 1B1 iSMILE tumor, undergoing a robotic radical hysterectomy with sentinel procedure, and one case undergoing a robotic-assisted pelvic/para-aortic lymph node staging dissection, confirming a metastatic FIGO-stage 3C2 (for primary chemo-radiotherapy treatment). CONCLUSION: Here, we report for the first time a few cases of (i)SMILE with different clinical presentations, their management and follow-up. Immunohistochemical characteristics are given for both primary lesions as well as the metastases.

Acute SARS-CoV-2 alpha variant infection leading to placental insufficiency and fetal distress.

The effect of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Alpha variant (also known as B.1.1.7 lineage, 20I/501Y.V1, the UK variant or VOC 202012/01) infection on pregnancy is currently unknown. We present a case of a 37-year-old woman admitted to our tertiary hospital at a gestational age of 29 weeks and 1 day because of oligohydramnios with reduced fetal movements for 10 days. About 20 days before admission, she tested positive for SARS-CoV-2 Alpha variant. The following day, due to abnormal cardiotocography, increased brain sparing, and absent end-diastolic flow in the umbilical artery, an urgent cesarean section was performed. The neonate had an uneventful admission to the neonatal intensive care unit. All neonatal samples proved negative for SARS-CoV-2. Pathological examination of the placenta revealed intervillous fibrin deposition, ischemic necrosis of villi and histiocytic intervillositis, corresponding with the SARS-CoV-2 placentitis triad. The placental tissue demonstrated a high viral load, possibly explaining the acute onset of placental insufficiently and subsequent fetal distress. This case demonstrates the importance of seeking medical care when experiencing reduced fetal movement in SARS-CoV-2 infected patients since acute infection can induce significant placental and subsequent fetal pathology.

Primary Angiosarcoma of the Central Nervous System: Case Report and Review of the Imaging Features.

Primary angiosarcoma of the central nervous system is a rare malignant tumor with only 28 reported cases so far. Imaging findings have only been reported in a few cases. We report a case of intracranial angiosarcoma in a Caucasian male and present a review of the imaging features in the recent literature. The tumor mostly presents as a well-demarcated, heterogeneous, moderately to strongly enhancing lesion with signs of intratumoral bleeding and surrounding vasogenic edema. The differential imaging features of common hemorrhagic intracranial tumors are discussed.

An unusual cervical tumor as presentation of a non-hodgkin lymphoma.

Rare cervical cancers are responsible for a minority of cases encountered by a clinician. However, behavioral patterns, management, and prognosis of certain rare cervical cancers differ from either squamous carcinomas or adenocarcinomas. Here we present a case of a locally advanced cervical tumor as a presentation of an extranodal cervical non-Hodgkin lymphoma (NHL), with a review of the current literature.

Altered expression of key players in vitamin D metabolism and signaling in malignant and benign thyroid tumors.

1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), the active form of vitamin D, mediates antitumor effects in various cancers. The expression of key players in vitamin D signaling in thyroid tumors was investigated. Vitamin D receptor (VDR) and CYP27B1 and CYP24A1 (respectively activating and catabolizing vitamin D) expression was studied (RT-PCR, immunohistochemistry) in normal thyroid, follicular adenoma (FA), differentiated thyroid cancer (DTC) consisting of the papillary (PTC) and follicular (FTC) subtype, and anaplastic thyroid cancer (ATC). VDR, CYP27B1, and CYP24A1 expression was increased in FA and DTC compared with normal thyroid. However, in PTC with lymph node metastasis, VDR and CYP24A1 were decreased compared with non-metastasized PTC. In ATC, VDR expression was often lost, whereas CYP27B1/CYP24A1 expression was comparable to DTC. Moreover, ATC with high Ki67 expression (>30%) or distant metastases at diagnosis was characterized by more negative VDR/CYP24A1/CYP27B1 staining. In conclusion, increased expression of key players involved in local 1,25(OH)(2)D(3) signaling was demonstrated in benign and differentiated malignant thyroid tumors, but a decrease was observed for local nodal and especially distant metastasis, suggesting a local antitumor response of 1,25(OH)(2)D(3) in early cancer stages. These findings advocate further studies with 1,25(OH)(2)D(3) and analogs in persistent and recurrent iodine-refractory DTC.

Diffuse alveolar hemorrhage induced by everolimus.

Pulmonary toxicity is a known complication of the proliferation signal inhibitor (PSI) sirolimus and consists of diverse entities such as interstitial pneumonitis, lymphocytic alveolitis, bronchiolitis obliterans with organizing pneumonia, and diffuse alveolar hemorrhage. Several cases of interstitial pneumonitis have also been reported with the more recently developed PSI everolimus. In this report, a case of diffuse alveolar hemorrhage attributed to everolimus is described. The patient presented with respiratory symptoms of insidious onset, ultimately resulting in severe respiratory failure characterized by high lactate dehydrogenase levels, patchy ground-glass infiltrates, and bloody BAL fluid with predominance of iron-loaded macrophages and monocytes. Withdrawal of the offending drug and temporary association of high-dose steroids resulted in a rapid recovery. Given that prompt drug discontinuation is potentially life saving, PSI-induced pulmonary toxicity should be considered in the differential diagnosis of patients treated with PSIs and presenting with respiratory symptoms or pulmonary lesions.

Generation of T cells from human embryonic stem cell-derived hematopoietic zones.

Human embryonic stem cells (hESC) are pluripotent stem cells. A major challenge in the field of hESC is the establishment of specific differentiation protocols that drives hESC down a particular lineage fate. So far, attempts to generate T cells from hESC in vitro were unsuccessful. In this study, we show that T cells can be generated in vitro from hESC-derived hematopoietic precursor cells present in hematopoietic zones (HZs). These zones are morphologically similar to blood islands during embryonic development, and are formed when hESC are cultured on OP9 stromal cells. Upon subsequent transfer of these HZs on OP9 cells expressing high levels of Delta-like 1 and in the presence of growth factors, cells expand and differentiate to T cells. Furthermore, we show that T cells derive exclusively from a CD34(high)CD43(low) population, further substantiating the notion that hESC-derived CD34(high)CD43(low) cells are formed in HZs and are the only population containing multipotent hematopoietic precursor cells. Differentiation to T cells sequentially passes through the physiological intermediates: CD34(+)CD7(+) T/NK committed, CD7(+)CD4(+)CD8(-) immature single positive, CD4(+)CD8(+) double positive, and finally CD3(+)CD1(-)CD27(+) mature T cell stages. TCRalphabeta(+) and TCRgammadelta(+) T cells are generated. Mature T cells are polyclonal, proliferate, and secrete cytokines in response to mitogens. This protocol for the de novo generation of T cells from hESC could be clinically and scientifically relevant.

Monoclonal antibody 14C5 targets integrin alphavbeta5.

This study identifies and characterizes the antigen recognized by monoclonal antibody (mAb) 14C5. We compared the expression of antigen 14C5 with the expression of eight integrin subunits (alpha1, alpha2, alpha3, alphav, beta1, beta2, beta3, and beta4) and three integrin heterodimers (alphavbeta3, alphavbeta5, and alpha5beta1) by flow cytometry. Antigen 14C5 showed a similar expression to alphavbeta5 in eight different epithelial cancer cell lines (A549, A2058, C32, Capan-2, Colo16, HT-1080, HT-29, and SKBR-3). Specific binding of P1F6, an anti-alphavbeta5 specific antibody, was blocked by mAb 14C5. After transient expression of alphavbeta5 in 14C5-negative Colo16 cells, mAb 14C5 was able to bind a subpopulation of alphavbeta5-positive cells. We evaluated the tissue distribution of the 14C5 antigen in colon (n = 20) and lung (n = 16) cancer tissues. The colon carcinoma cells stained positive for 14C5 in 50% of tumors analyzed, whereas bronchoalveolar lung carcinoma and typical carcinoid were not positive for the antigen. More common types of non-small cell lung cancer, i.e., squamous (n = 5) and adenocarcinoma (n = 3), stained positive in 2 of 5 squamous carcinomas and in 1 of 3 investigated adenocarcinoma. Colon (95%) and lung (50%) carcinoma tissues showed extensive expression of antigen 14C5 in the stroma surrounding the tumor cells and on the membrane of the adjacent fibroblasts. We show for the first time that mAb 14C5 binds the vascular integrin alphavbeta5, suggesting that mAb 14C5 can be used as a screening agent to select colon and lung cancer patients that are eligible for anti-alphavbeta5-based therapies.

Over-expression of heat shock protein 70 in mice is associated with growth retardation, tumor formation, and early death.

Experiments in lower organisms, such as worms and flies, indicate that the molecular chaperone protein heat shock protein 70 (HSP70) is a longevity factor. In contrast, we demonstrate here that mice overexpressing HSP70 display growth retardation and early death. HSP70 transgenic mice displayed increased levels of serum corticosterone and weaker expression and activity of the glucocorticoid receptor in the liver. Serum insulin-like growth factor-1 (IGF-1) concentrations in the transgenic mice were 50% lower than in the control mice, leading to growth retardation. HSP70 transgenic mice showed decreased expression of Casp9, which encodes caspase-9, and increased expression of the anti-apoptotic Bcl-2 gene, indicating that apoptosis is suppressed. Consequently, most of the transgenic animals died before the age of 18 months from tumors in their lungs and lymph nodes. We suggest that the proinflammatory and antiapoptotic effects of HSP70 might be responsible for the growth retardation, tumor formation, and early death observed in the HSP70 transgenic mice.

The yield of endoscopic ultrasound in lung cancer staging: does lymph node size matter?

INTRODUCTION: Transoesophageal endoscopic ultrasound with fine-needle aspiration (EUS-FNA) is a minimally invasive procedure to demonstrate unresectability in lung cancer patients with enlarged malignant mediastinal lymph nodes (MLN). We compared the performance of EUS-FNA to show malignant invasion in enlarged versus small MLN. METHODS: A single center analysis was performed in lung cancer patients with a suspicion for malignant MLN invasion based on the available imaging. In these patients, EUS-FNA was presumed to impact the diagnostic course since patients underwent surgical-pathologic verification only when EUS-FNA did not demonstrate MLN invasion. RESULTS: We evaluated 100 lung cancer patients in whom MLN invasion was presumed based on the available imaging. In 75 patients (75%), there was at least one enlarged MLN, whereas in 25 patients (25%), only small MLN were found. The sensitivity and negative predictive value to detect malignancy in enlarged MLN was 96% (95% confidence interval [CI], 87-99) and 67% (95% CI, 29-92), respectively. The sensitivity and negative predictive value of EUS-FNA in small MLN was 93% (95% CI, 66-99) and 92% (95% CI, 61-99), respectively. EUS-FNA prevented a surgical (mediastinal) intervention in 88 and 52% of the patients with enlarged or small MLN, respectively (p < 0.001). CONCLUSIONS: As the sensitivity to detect malignant MLN invasion is comparably high for both enlarged and small but suspected MLN, clinicians should consider EUS-FNA even in case computed tomography-scan shows no enlarged MLN. The impact of EUS-FNA to avoid surgical mediastinal interventions is greater when enlarged MLN are present. The moderate negative predictive value of EUS-FNA makes surgical-pathologic verification still compulsory, regardless of the size of the MLN.

Endoscopic ultrasound reduces surgical mediastinal staging in lung cancer: a randomized trial.

RATIONALE: Assessment of mediastinal lymph nodes is recommended in patients with non-small cell lung cancer without distant metastases. Linear transesophageal endoscopic ultrasound with real-time guided fine-needle aspiration (EUS-FNA) is a promising, nonsurgical tool for mediastinal staging. OBJECTIVES: We conducted a randomized controlled trial comparing surgical staging with EUS-FNA. METHODS: Patients with proven or suspected non-small cell lung cancer in whom mediastinal exploration was required were randomly assigned to undergo EUS-FNA or the appropriate surgical staging procedure. When EUS-FNA did not show malignant lymph node invasion, a confirmatory surgical staging procedure was done. A negative surgical staging procedure was followed by thoracotomy with systematic lymph node sampling. The primary endpoint was the rate of surgical staging interventions. The secondary endpoints were test performance of EUS-FNA and surgical staging, morbidity, and length of hospital stay, considering surgical staging was performed as an in-patient procedure. MEASUREMENTS AND MAIN RESULTS: A total of 40 patients were randomized: 19 to EUS-FNA, and 21 to surgical mediastinal staging. Patient and tumor characteristics were well balanced between both groups. For patients allocated to EUS-FNA, surgical staging was needed in 32% (P < 0.001). The sensitivity to detect malignant lymph node invasion was 93% (95% confidence interval, 66-99%) for EUS-FNA and 73% (95% confidence interval, 39-93%) for surgical staging (P = 0.29). Complication rate was 0% for EUS-FNA and 5% for surgical staging (P = 1.0). The median hospital stay was significantly shorter for EUS-FNA than for surgical staging (0 vs. 2 nights; P < 0.001). CONCLUSIONS: EUS-FNA reduces the need for surgical staging procedures in patients with (suspected) lung cancer in whom a mediastinal exploration is needed.