Pleuropulmonary blastoma (PPB) and other DICER1-associated high-grade malignancies are morphologically, genetically and epigenetically related - A comparative study of 4 PPBs and 6 sarcomas.

DICER1-related tumors occur hereditary or sporadically, with high-grade malignancies sharing clinicopathological and (epi)genetic features. We compared 4 pleuropulmonary blastomas (PPBs) and 6 sarcomas by mutation analysis, whole transcriptome sequencing and methylation profiling. 9/10 patients were female. PPB patients were 0-4 years. 3/4 were alive; 2 without disease. One patient died of metastatic disease (median follow-up, 16 months). Sarcoma patients were 16-56 years. Locations included: uterine cervix/corpus (3/1), soft tissue back/shoulder (1) and paravertebral (1). 5/6 patients were alive; 2 developed metastases: intracranial (1) and lung and kidney (1) (median follow-up, 17 months). The deceased patient previously had a PPB and a Sertoli-Leydig cell tumor. Histologically, tumors showed atypical primitive-looking cells with incomplete rhabdomyoblastic differentiation and cartilage (n = 5). Immunohistochemistry demonstrated desmin- (n = 9/10), myogenin- (n = 6/10) and keratin positivity (n = 1/1). Eight cases harbored biallelic DICER1 mutations with confirmed germline mutations in 4 cases. Two cases showed a monoallelic mutation. By RNA expression- and methylation profiling, distinct clustering of our cases was seen demonstrating a close relationship on (epi)genetic level and similarities to embryonal rhabdomyosarcoma. In conclusion, this study shows overlapping morphological, immunohistochemical and (epi)genetic features of PPBs and DICER1-associated high-grade sarcomas, arguing that these neoplasms form a spectrum with a broad clinicopathological range.

Analysis of PD-1, PD-L1, and T-cell infiltration in angiosarcoma pathogenetic subgroups.

Angiosarcoma (AS) is a rare malignancy with a poor prognosis. It can develop spontaneously or due to previous radiotherapy (RT), ultraviolet (UV) radiation, or lymphoedema (Stewart Treves AS). Novel therapeutic approaches are needed, but progress is hindered because of the heterogeneity and rarity of AS. In order to explore the potential of immune checkpoint inhibition (ICI), we investigated the protein expression of programmed cell death 1 (PD-1), programmed death-ligand 1 (PD-L1), and CD8 + T cells in 165 AS cases in relation to AS subgroups based on clinical classification and in relation to whole-genome methylation profiling based clusters (A1, A2, B1, B2). High PD-L1 and PD-1 expression were predominantly shown in UV-associated, visceral, and soft tissue AS. RT-associated AS showed predominantly high PD-1 expression. CD8 + T cell infiltration was present in the majority of AS samples. Within the UV-associated AS, two different clusters can be distinguished by DNA methylation profiling. Cases in cluster A1 showed higher PD-1 (p = 0.015), PD-L1 (p = 0.015), and CD8 + T cells (p = 0.008) compared to those in cluster B2, suggesting that these UV-AS tumors are more immunogenic than B2 tumors showing a difference even within one subgroup. In soft tissue AS, combined PD-1 and PD-L1 expression showed a trend toward poor survival (p = 0.051), whereas in UV-associated AS, PD-1 expression correlated with better survival (p = 0.035). In conclusion, we show the presence of PD-1, PD-L1, and CD8 + T cells in the majority of AS but reveal differences between and within AS subgroups, providing prognostic information and indicating to be predictive for ICI.

Infantile fibrosarcoma with an EGFR kinase domain duplication: Underlining a close relationship with congenital mesoblastic nephroma and highlighting a similar morphological spectrum.

Infantile fibrosarcoma (IFS) and congenital mesoblastic nephroma (CMN) are locally aggressive tumors primarily occurring in infants. Both IFS and the cellular subtype of CMN show overlapping morphological features and an ETV6-NTRK3 fusion, suggesting a close relationship. An activating alteration of EGFR, based on an EGFR kinase domain duplication (KDD), occurs in a subset of CMNs lacking an NTRK3 rearrangement, especially in the classic and mixed type. So far no EGFR-KDDs have been detected in IFS. We describe four pediatric tumors at the extremities (leg, n = 2; foot and arm n = 1) with histological features of IFS/CMN. Two cases showed classic IFS morphology while two were similar to classic/mixed type CMN. In all cases, an EGFR-KDD was identified without detection of a fusion gene. There were no abnormalities of the kidneys in any of the patients. This is the first description of IFS with an EGFR-KDD as driver mutation, supporting that IFS and CMN are similar lesions with the same morphological and genetic spectrum. Pathologists should be aware of the more fibrous variant of IFS, similar to classic/mixed type CMN. Molecular analyses are crucial to treat these lesions adequately, especially with regard to the administration of tyrosine kinase inhibitors.

Targeting angiosarcomas of the soft tissues: A challenging effort in a heterogeneous and rare disease.

Angiosarcomas are rare malignant tumors with a heterogeneous clinical presentation and generally poor prognosis. It has been difficult to establish consistent molecular characteristics and driver events in angiosarcoma development. Oncogenic and angiogenesis-related pathways have been investigated pre-clinically and clinically with varying results. A few promising responses to checkpoint inhibitors have been described, but immunological features require further elucidation. With this review we present an overview of the critical biological pathways and processes affected in angiosarcoma, and their potential role in novel, non-cytotoxic, systemic treatments.

Clinicopathological characteristics and outcome of 31 patients with ETV6-NTRK3 fusion gene confirmed (mammary analogue) secretory carcinoma of salivary glands.

OBJECTIVES: In 2010, a new subtype of salivary gland cancer (SGC), (mammary analogue) secretory carcinoma (SC), was defined, characterized by the ETV6-NTRK3 fusion gene. As clinical behavior and outcome data of this histological subtype tumor are still sparse, we aimed to describe the clinicopathological course and outcome of a series of translocation positive SC patients. PATIENT AND METHODS: We re-evaluated the pathological diagnosis of a subset of SGCs, diagnosed in 4 of 8 Dutch head and neck centers. Subsequently, tumors with a morphological resemblance to SC were tested for the ETV6-NTRK3 fusion gene using RT-PCR. Furthermore, patients prospectively diagnosed with SC were included. The clinical characteristics and outcomes were retrieved from the patient files. RESULTS: Thirty-one patients with ETV6-NTRK3 fusion gene positive SC were included. The median age was 49 years, 17 patients (55%) were male. Eighteen tumors (58%) arose in the parotid gland. One patient presented with lymph node metastasis. All patients underwent tumor resection and 4 patients had a neck dissection. Four patients had re-resection and 15 patients (48%) received postoperative radiotherapy. One patient developed a local recurrence, no regional recurrences or distant metastases were observed. After a median follow-up of 49 months the 5- and 10-year overall survival were 95%, the 5- and 10-year disease free survival were 89%. CONCLUSION: The clinical course of SC is favorable with a low rate of locoregional recurrence and excellent survival. Given the low incidence of nodal metastases, elective neck treatment, i.e. surgery and/or radiotherapy, does not seem to be indicated.

Treatments of tenosynovial giant cell tumours of the temperomandibular joint: a report of three cases and a review of literature.

Tenosynovial giant cell tumours (TGCTs) are benign lesions affecting synovial joints. The classified subtypes are localized and diffuse. They seldom occur in the temporomandibular joint (TMJ). The aim of this study is to report on three new cases and to review the literature. One patient had surgical debulking with adjuvant external beam radiation therapy (EBRT). After 1year of follow-up, no evidence of disease was presented. The second patient was misdiagnosed and treated with denosumab. Debulking with adjuvant EBRT followed. Ten months postoperatively, no disease progression was seen. The third patient received systemic nilotinib and remained stable for over 5years. The literature review included 106 cases of which 95 had diffuse subtype. Most patients, had surgical excision. Thirteen (14%) patients received adjuvant EBRT. Eleven (14%) recurrences were identified. After 1-, 5- and 10 years of follow-up, an overall progression-free survival (PFS) of 99% (95% confidence interval (CI) 0.96-1), 80% (95% CI 0.68-0.94), 67% (95% CI 0.51-0.90) was calculated, respectively. Treatments for diffuse-TGCT-TMJ should be individualized depending on age, severity of symptoms, extent of disease and progression, expected mutilation of surgical interference, and current systemic treatment options. In stable disease a 'wait and see' policy, is a viable option. Additional treatments should be reserved for symptomatic, irresectable tumours or residual disease after surgical treatment with persistent complaints.

Transanal endoscopic microsurgery following treatment with imatinib : a case report of a patient with a rectal gastrointestinal stromal tumor.

BACKGROUND: Gastrointestinal stromal tumors (GIST) of the rectum are a challenge for the colorectal surgeon. In case of a locally advanced rectal GIST, an extended or multivisceral resection with significant morbidity and -mortality is often necessary. Literature is lacking on the combined modality of transanal endoscopisc microsurgery (TEM) following imatinib for these patients. METHODS: We describe a combined approach for a locally advanced GIST of the rectum with preoperative imatinib -treatment and subsequent local excision using the TEM procedure. RESULTS: After six months of treatment with imatinib the TEM procedure was successfully performed with a radical -resection of the remnant tumor. Twenty-four months after surgery this patient has no evidence of disease. CONCLUSIONS: A TEM procedure following treatment with imatinib may safely be performed in selected patients with a locally advanced GIST.

Sarcoma botryoides in an infant.

A 17-month-old girl with no medical history presented at our emergency room with abnormal vaginal bleeding and vaginal tissue loss with a "grape bunch" appearance. Physical examination showed no abnormalities, but gynaecological examination showed abnormal vaginal tissue protruding through the vagina introitus. Given the typical clinical presentation, the age of the girl and the location and aspect of the lesion, there was a high suspicion of the botryoid variant of embryonal rhabdomyosarcoma of the vagina. Histology of a biopsy of the lesion was consistent with embryonal rhabdomyosarcoma. As no metastases were detected, the girl received chemotherapy. This case report describes the importance of early recognition of the typical clinical symptoms of sarcoma botryoides, since a rapid diagnosis followed by treatment is necessary to prevent death.

Prognostic and therapeutic relevance of the IGF pathway in Ewing's sarcoma patients.

The optimal target and timing of drugs interfering with the insulin-like growth factor (IGF) signaling system in Ewing's sarcoma (ES) remain undetermined. We examined the expression of IGF signaling proteins in ES samples taken before and after chemotherapy, and speculate about the optimal way of treating ES patients in the future. Tumor material (36 initial biopsies and 24 resection specimens after neoadjuvant chemotherapy) and follow-up data of 41 patients treated for ES at the Radboud University Nijmegen Medical Centre were analyzed. Immunohistochemical staining was done for IGF1, IGF2, IGFBP3, IGF-1R, phosphorylated AKT (pAKT), phosphorylated mTOR (pmTOR), and phosphorylated ERK (pERK), and staining intensity was scored semiquantitatively. Change of protein expression during treatment, correlations of effector cascade signaling, and influence on progression-free (PFS) and overall survival (OS) were tested. All potential targets were widely expressed at both time points. After chemotherapy, pmTOR expression decreased significantly (p = 0.021) while IGFBP3 increased (p = 0.005). Correlations exist between IGF-1R and pERK (ρ = 0.286, p = 0.031), IGF-1R and pAKT (ρ = 0.269, p = 0.045), pAKT and pERK (ρ = 0.460, p = 0.000), and pERK and pmTOR (ρ = 0.273, p = 0.038). In therapy-naive samples, combined expression of pAKT, pmTOR, and pERK predicted worse PFS (median, 11 vs. 32 months; p = 0.039) and OS (median, 18 vs. 83 months; p = 0.023). We identify an unfavorable prognostic group of ES patients with widely activated IGF-effector cascades, demonstrate cooperation between the different downstream pathways, and show how expression of IGF-related proteins may change after exposure to chemotherapy. These findings should be taken into account when designing future trials with IGF-targeting agents. We suggest the prospective exploration of chemotherapy and multi-target tyrosine kinase inhibitors in the first-line setting.

[Pathology along the liver sinusoids: endothelial and perisinusoidal findings]. / Pathologie entlang der sinusoidalen Wegstrecke: sinusendotheliale und perisinusoidale Befunde.

Sinusoidal alterations unrelated to primary hepatocellular damage present without characteristic clinical findings and in these cases the liver biopsy is particularly important. Capillarization of sinusoids is characterized by closing of fenestration, formation of a basal membrane and by the expression of CD34 and is typical for active cirrhosis. In nodular regeneratory hyperplasia, capillarization indicates a local or general disturbance of perfusion. In large regenerative nodules, focal nodular hyperplasia and liver cell adenoma CD34-positive capillaries reflect afferent parts and CD34-negative sinusoids the efferent parts of the parenchymal vascular bed. HCC generally have a completely capillarized CD34-positive vascular bed. Hepatic angiosarcomas and epithelioid hemangioendotheliomas can be easily overseen in liver biopsies, if they spread along the sinusoids without detoriation of the acinar architecture and without significant alteration of the surrounding liver cell plates. Toxic damage of endothelial cells, post-sinusoidal stasis and sinusoidal hyperperfusion are the underlying pathogenetic principles of sinusoidal injury. Rupture and loss of the perisinusoidal reticulin fibres lead to peliosis hepatis. In these cases liver biopsy might disclose occlusion of the terminal liver veins (VOD). Perisinusoidal fibrosis can be caused by intrasinusoidal accumulation of pathologic cells, advanced intrasinusoidal macrophagocytic storage diseases and by activation of the vitamin A-storing hepatic stellate cells. Perisinusoidal amyloidosis can be the first sign of an underlying B-cell neoplasia.

[Pathology along the liver sinusoids: intrasinusoidal findings]. / Pathologie entlang der sinusoidalen Wegstrecke: intrasinusoidale Befunde.

Pathological findings in the liver sinusoids are mostly caused by extrahepatic or systemic diseases. Unclear fever, hepatosplenomegaly, portal hypertension or a mild elevation of liver enzymes are reasons for a liver biopsy leading to path-breaking diagnoses. Reactive intrasinusoidal lymphocytosis, especially with Epstein-Barr virus infections, has to be differentiated from predominantly intrasinusoidal lymphoproliferative malignancies. Intrasinusoidal megakaryocytes can be the first sign of a myeloproliferative or myelodestructive disease. Intrasinusoidal carcinosis and melanomatosis might present radiologically without tumor lesions and are easily overlooked histologically, in particular, if the critical cells have a similar size to hepatocytes. This also applies for intrasinusoidal storing macrophages. Gaucher's disease type I, and some other subtypes of inborn storage diseases might present for the first time in adulthood by hepatomegaly and Kupffer cell hypertrophy. Accompanying perisinusoidal fibrosis and immunohistochemical staining (CD68) can help to detect the large pale intrasinusoidal macrophages. In immunocompromized patients with fever, particular attention must be paid to intracellular agents, especially atypical mycobacteria and yeasts in non-granulomatous nested or dispersed Kupffer cells. Leishmaniasis with amastigotes in macrophages is accompanied by reactive sinusoidal plasmocytosis.

Immunoreactivity of cytokeratins (CK7, CK20) and mucin peptide core antigens (MUC1, MUC2, MUC5AC) in adenocarcinomas, normal and metaplastic tissues of the distal oesophagus, oesophago-gastric junction and proximal stomach.

AIMS: Adenocarcinomas of the distal oesophagus and especially the oesophago-gastric junction have shown an increasing incidence during the last decade. Definition of subgroups according to different sites of development, histogenesis or aetiology may prove to be valuable for clinical diagnosis and treatment. Previous studies have shown differences in cytokeratin patterns between Barrett's metaplasia of the oesophagus and intestinal metaplasia in the stomach. The aim of our study was to investigate whether the expression of certain cytokeratins (CK7, CK20) and mucins (MUC1, MUC2, MUC5AC) exhibit clear-cut patterns, thus allowing a subclassification of adenocarcinomas of the oesophago-gastric junction. The possibility of a relationship between antigen expression and the presence or absence of Barrett's metaplastic epithelium was also studied. METHODS AND RESULTS: CK7, CK20, MUC1, MUC2 and MUC5AC were visualized in six adenocarcinomas of the distal oesophagus, 29 adenocarcinomas of the oesophago-gastric junction and eight adenocarcinomas of the proximal stomach. CK7, CK20 and MUC1 were strongly expressed in the great majority of all neoplasms under study, whereas MUC2 and MUC5AC were absent or only faintly detectable. CK20 exhibited a significantly stronger expression in poorly differentiated tumours (G3) and MUC1 immunoreactivity correlated with tubular and papillary versus signet-ring cell histopathology. Other statistically significant correlations between antigens and histopathological features (pTNM stage, grading, histopathological subtype, presence/absence of Barrett's epithelium) were not observed. CONCLUSIONS: According to our results, most adenocarcinomas of the oesophago-gastric junction show a CK7+, CK20+, MUC1+ phenotype irrespective of the presence or absence of Barrett's epithelium. The immunohistochemical data suggest a similar histogenesis of these tumours.

Comparative evaluation of the prognostic value of MUC1, MUC2, sialyl-Lewis(a) and sialyl-Lewis(x) antigens in colorectal adenocarcinoma.

AIMS: The significance of MUC1, MUC2 and sialylated Lewis blood group antigens as prognostic markers in colorectal adenocarcinoma was investigated in a large series of patients because previous investigations revealed inconsistent results due to unrelated tumour samples from different patient groups and methodological differences. METHODS AND RESULTS: Tissues from 243 patients with colorectal adenocarcinoma were stained immunohistochemically. MUC1 showed a strong immunoreactivity (in more than 35% of the tumour area) in 32.5%, MUC2 in 51.0%, sialyl-Lewis(x) in 67.9% and sialyl-Lewis(a) in 73.7% of the cases, respectively. MUC1 immunoreactivity displayed a significant correlation with tumour progression as reflected by advancing pTNM staging and poor differentiation. MUC2 expression was significantly stronger in mucinous adenocarcinomas. Sialyl-Lewis(x) immunostaining correlated with the extent of lymph node metastasis as well as low cytological differentiation. According to univariate and multivariate analysis (P < 0.0001) only MUC1 reactivity represented a marker of worse survival probability, opposed to the sialylated Lewis antigens that did not exert a predictive value. CONCLUSIONS: According to our data, MUC1 and sialyl-Lewis(x) immunoreactivity exhibit statistically significant correlations with established markers of tumour progression. However, only MUC1 presents as an independent prognostic factor of colorectal adenocarcinoma.

Immunoreactivity of Lewis blood group and mucin peptide core antigens: correlations with grade of dysplasia and malignant transformation in the colorectal adenoma-carcinoma sequence.

Previous studies on the immunoreactivity of various mucin peptide and carbohydrate antigens in neoplastic colorectal tissues led to at least in part contradictory results. Therefore, we investigated a series of 42 adenomas and 44 carcinomas applying monoclonal antibodies (mabs) directed against Lewis blood group antigens (sialyl-Le(a), Le(x), sialyl-Le(x), Le(y)) as well as mucin peptide cores (MUC1, MUC2 and MUC5AC) by immunohistochemistry. A statistically significant positive correlation between the development of high-grade dysplasia in colorectal adenomas and the immunoreactivity of Le(y) and MUC1 epitopes was observed, whereas MUC2 exhibited a significant negative correlation. The reactivity of the other epitopes did not show an association with the progression of malignant transformation. Colorectal carcinomas were subdivided according to their histopathological subtype. The immunohistochemical staining resulted in a significantly stronger MUC2 reactivity of mucinous vs. tubular adenocarcinomas. Immunoreactivity of the MUC1-specific mab, which does not react with the fully glycosylated peptide core, showed a statistically non-significant inverse tendency, whereas all carbohydrate antigens displayed a strong expression in both tumor subtypes. Furthermore, correlations between mucin peptide and carbohydrate epitope labelling were evaluated. Progression of the adenoma-carcinoma sequence was accompanied by an increase of Le(y) as well as MUC1 antigen and an increase of all Lewis antigens compared to MUC2 immunoreactivity. On the other hand, mucinous carcinomas exhibited an inverse pattern. In conclusion, these results demonstrate that Le(y) and MUC1 immunoreactivity correlate with malignant transformation in the colorectum, whereas MUC2 represents a marker for low-grade dysplasia and the subtype of mucinous carcinomas.