Case report: Primary pulmonary low grade fibromyxoid sarcoma progressing to dedifferentiation: probably due to TP53 driver mutation.

Low Grade Fibromyxoid Sarcoma (LGFMS), a rare entity characterized by bland histologic features, typically affects deep soft tissues of the trunk and lower extremities. Rare cases have been reported arising from the viscera and few demonstrating morphology of high-grade dedifferentiation. Here we report a 39-year-old Chinese woman presenting with primary lung LGFMS, which metastasized to the pancreas five years after diagnosis and then relapsed ten years later as a mediastinum mass. Microscopically, the lung and pancreatic lumps shared similar classical features of LGFMS, composed of bland spindle-shaped cells with low mitotic activity. However, the mediastinal mass had dedifferentiated morphology of dense sheets of round and epithelioid cells with high degree of nuclear pleomorphism and brisk mitosis. Molecular studies showed both classical and dedifferentiated areas had FUS::CREB3L2 rearrangement. However, the mediastinal dedifferentiated area presented with extra H193Y mutation of the TP53. Moreover, the mediastinal tumor displayed a strong and diffuse pattern of p53 expression immunohistochemically, but the primary lung and secondary pancreatic masses did not. Thus, we diagnosed the mediastinal mass as dedifferentiated LGFMS and proposed that TP53 mutation was probably the driver gene alteration in the process, which, to the best of our knowledge, has not been reported in the existing literature.

De novo dedifferentiated SDH-deficient gastrointestinal stromal tumor with MDM2 amplification: case report and literature review.

The dedifferentiation of the gastrointestinal stromal tumors (GISTs) has been reported in a small number of cases, usually under the pressure of the tyrosine kinase inhibitor (TKI) treatment. Herein, we described a de novo dedifferentiated GIST with the SDH deficiency in a 32-year-old Chinese woman. The tumor was located on the lesser curvature of the gastric antrum, measuring 4.1x9.1 cm2. Microscopically, the tumor was composed of 2 distinct morphological populations, mild epithelioid cells arranged in the multinodular growth pattern and hyperchromatic spindle cells arranged in the fascicular or sheet-like architecture. The two zones showed different immunophenotypes. The former proved to be an epithelioid GIST with the positive expression for C-KIT, DOG-1, and CD34, and the latter expressed the CKpan and P53, but negative for the C-KIT, DOG-1, and CD34. However, the SDHB staining was negative in both areas. Genetically, the next-generation sequencing (NGS) analysis showed the SDHC mutation (p.S48*) in both components and the MDM2 amplification was only in the spindle cell area. The lesion was diagnosed as the SDH-deficient GIST with the epithelial cell dedifferentiation. We proposed that the P53 associated gene alteration or other alternative escape mechanisms for the KIT-independent signaling pathways might play a role in the dedifferentiation.

Prognostic analysis of extrameningeal solitary fibrous tumor using the modified Demicco model: a clinicopathologic study of 111 Chinese cases.

Introduction: Solitary fibrous tumor (SFT) represents a fibroblastic neoplasm exhibiting NAB2::STAT6 gene rearrangement, displaying diverse clinical manifestations, spanning from benign to malignant. To predict prognosis, the modified (four-variable) Demicco (mDemicco) model was introduced. This investigation aims to authenticate the mDemicco risk model's precision in Asian patients while investigating the clinicopathological and molecular factors linked to the prognosis of extrameningeal SFTs. Methods: Clinicopathological data from 111 extrameningeal SFT cases in East China, covering the period from 2010 to 2020, were thoroughly analyzed. The tumors were classified using the mDemicco model. Immunohistochemical evaluation of P16 and P53, molecular detection of TP53 and TERT promoter mutation, and fluorescence in situ hybridization for CDKN2A gene alterations were performed. Statistical methods were utilized to assess the associations between clinicopathological or molecular factors and prognosis. Results: Histologically, only one parameter, the mitotic count, exhibited a statistical correlation with progression-free survival (PFS) and overall survival (OS). During the Kaplan-Meier analysis, the variation in PFS among the different risk groups exhibited a notable trend towards statistical significance. Nevertheless, 3 out of 74 patients classified as low-risk SFTs and 7 out of 21 patients classified as intermediate-risk exhibited disease progression. Among the 5 patients with TP53 mutations and/or mutant-type P53 immunophenotype, 3 experienced disease progression, including 2 intermediate-risk patients. Additionally, among the 4 patients with TERT promoter mutations who were followed up, 3 showed progression, including 2 intermediate-risk patients. Moreover, it was observed that hemizygous loss of CDKN2A was detected in more than 30% of one case, yet the patient exhibited a favorable survival outcome. Conclusion: The mDemicco risk model exhibits certain limitations when dealing with smaller tumor sizes, younger age groups, and occurrences of malignant and dedifferentiated SFTs. Furthermore, molecular factors, such as TP53 or TERT promoter mutations, may identify intermediate-risk SFTs with poorer prognoses.

Case report: ALK-rearranged spindle and epithelioid cell neoplasms with S100 and CD34 co-expression: Additional evidence of kinase fusion-positive soft tissue tumors.

ALK rearrangements have rarely been reported in S100- and CD34-co-expressing soft tissue neoplasms with lipofibromatosis-like neural tumor (LPFNT) pattern or stromal and perivascular hyalinization, mimicking NTRK-rearranged spindle cell tumors. Here, we reported ALK fusions involving related partner genes in two adult soft tissue tumors with S100 and CD34 co-expression, and conducted a literature review of mesenchymal tumors harboring ALK or other kinase fusions. Case 1 was a 25-year-old female who underwent excision of a soft tissue mass in the anterior thigh region. Morphologically, the tumor was composed of spindle cells adjacent to epithelioid cells embedded in myxedematous and hyalinized stroma, with infiltrative boundary. Spindle cells mixed with inflammatory infiltration resembling inflammatory myofibroblastic tumor (IMT) were seen sporadically. However, brisk mitosis and focal necrosis was also observed, indicating an intermediate-grade sarcoma. In case 2, the left side of the neck of a 34-year-old man was affected. The tumor was composed of monomorphic spindle cells arranged in fascicular growth or patternless pattern, with stromal and perivascular hyalinization. Sparse inflammatory cell infiltration was also observed. Both tumors showed CD34, S100, and ALK-D5F3 immunoreactivity. Next generation sequencing (NGS) test identified a PLEKHH2::ALK fusion in case 1, which was confirmed by RT-PCR and Sanger sequencing, whereas the RT-PCR (ARMS method) test detected an EML4::ALK fusion in case 2. In conclusion, this study expands the morphological and genetic landscape of tumors with S100 and CD34 co-expression harboring kinase fusions, and suggests that kinase fusion-positive mesenchymal neoplasms are becoming an enlarging entity with a variety of morphological patterns.

Rechallenge of immune checkpoint inhibitors in a case with adverse events inducing myasthenia gravis.

The mechanism(s) of immune checkpoint inhibitor (ICI)-induced myasthenia gravis (MG), an immune-related adverse event (irAE) that is fatal and limits subsequent ICI use, remain unexplored. Here, through comparative genomic analysis, we identified a pathogenic p.S467C germline variant in SLC22A5 in a thymoma case with ICI-induced MG, which was found to be associated with fatty acid oxidation through its regulation on L-carnitine levels. Remarkably, ICI rechallenge with L-carnitine pretreatment led to durable response without MG-related symptoms. Thus, we provide the first clinical evidence of genetic test-directed irAE management, which integrates individualized ICI treatment into the evolving paradigm of cancer management.

Diffuse intrathyroidal dissemination of papillary thyroid carcinoma with no stromal fibrosis at presentation: A pattern of aggressive differentiated thyroid carcinoma.

BACKGROUND: Multifocal Papillary thyroid carcinoma (PTC) is a very common condition. In certain cases, it is possible to find tens to hundreds of foci with a diffuse intrathyroidal spread in the whole thyroid with no stromal fibrosis. Herein, PTC with such features was nominated as diffuse disseminate variant (DDV) PTC. The aim of the present study was to investigate the histopathological characteristics, molecular features, and biological behavior of DDV and compare the characteristics of DDV to diffuse sclerosing variant (DSV) PTC. MATERIALS AND METHODS: Thirty-four DDV and 23 DSV cases were identified from consecutive surgical specimens diagnosed with PTC between 2014 and 2019. Targeted next-generation sequencing (NGS) was applied to investigate the mutation spectrum of DDV and DSV. RESULTS: DDV was commonly diagnosed in young patients and exhibited high rates of LNM (100 %), ETE (61.8 %), and LVI (44.1 %); however, they did not differ from DSV (P > 0.05). Male patients were more frequently diagnosed with DDV than with DSV (P < 0.001). The size of the largest tumor was significantly greater in DDV than in DSV patients (P = 0.008). In addition, BRAFV600E mutation was significantly higher in the DDV than in the DSV group (P < 0.001). The RET/PTC rearrangement was more frequent in DSV than in DDV patients; however, the difference was not statistically significant (P = 0.106). Moreover, DDV had a higher rate of recurrence compared to DSV treated with the same protocol (total thyroidectomy followed by radioactive iodine (RAI) treatment) (47.1 % and 8.7 %, P = 0.002). CONCLUSIONS: DDV should be regarded as a novel aggressive variant of PTC with distinct clinicopathological characteristics, aggressive biological behaviors, and a high recurrence.

Genetic and Pathological Characteristic Patterns of a Family With Neuronal Intranuclear Inclusion Disease.

Neuronal intranuclear inclusion disease (NIID) is a rare, progressive neurodegenerative disorder. This study aimed to investigate clinical, imaging, genetic, and dermatopathological characteristics of a family with adult-onset NIID. The proband was a 62-year-old woman with 3 brothers and 2 sisters. Of these, 4 had symptoms of paroxysmal visual field defect, extrapyramidal symptoms, dysautonomia, emotional changes, and cognitive dysfunction. Genetic examination revealed no abnormality related to cerebrovascular diseases. More than 200 CGG repeats of FMR1 gene cause fragile X-associated tremor/ataxia syndrome (FXTAS) whereas repeats of the proband were found 29 times, which excluded FXTAS. Quantitative reverse transcription polymerase chain reaction (PCR) and GC-rich-PCR identified an expanded GGC repeat (with ∼100 repeats) in the 5' region of NOTCH2NLC in the patient and her 2 younger brothers. Pathological examination found eosinophilic intranuclear inclusions inside adipocytes, fibrocytes, and sweat gland cells. Immunohistochemistry and immunofluorescence staining revealed positive staining for ubiquitin and p62. The detailed pathological and genetic features of this NIID family provide a valuable contribution to the existing knowledge base of this rare disorder.

Inflammatory myofibroblastic tumor arising from soft tissues of extremities harboring a novel CLIP2-ALK fusion.

A 34-year-old Chinese woman found a lump in her left leg for more than 3 weeks without any discomfort. Grossly, the tumor was relatively well delineated with focal infiltration. Histopathologic evaluation showed a compact fascicular spindle cell proliferation with variable myxoid and collagenous stroma and scattered inflammatory infiltrate. Immunohistochemically, the tumor cells showed positive expression of ALKD5F3 and SMA and negative expression of CD34, desmin, and cytokeretin. Fluorescence in situ hybridization analysis of the ALK locus showed break-apart signals in 20% of tumor cells, and DNA sequencing discovered a novel CLIP2-ALK fusion gene. The lesion was diagnosed as an inflammatory myofibroblastic tumor (IMT). To the best of our knowledge, this is the first case with CLIP2-ALK gene fusion in the somatic soft tissue IMTs.

A low-grade malignant soft tissue tumor with S100 and CD34 co-expression showing novel CDC42SE2-BRAF fusion with distinct features.

Recently, a novel group of spindle cell tumors defined by S100 and CD34 co-expression harboring recurrent fusions involving RET, RAF1, BRAF, and NTRK1/2 gene has been identified. Morphologically, they are characterized by monomorphic neoplasm cells, "patternless" growth pattern, stromal, and perivascular hyalinization, lacked necrosis. We reported a 52-year-old Chinese female patient with a S100 and CD34 co-expression sarcoma presenting in the right proximal forearm. The forearm mass initially emerged 19 months ago when it was misdiagnosed as a solitary fibrous tumor and was surgically removed without further treatment. Microscopically, the primary and the recurred tumors share the same features, resembling the morphology of the recently characterized group. Nevertheless, some distinct features, such as predominantly epithelioid tumor cells and focally staghorn vessels, were also present in our case. Genomic profiling with clinical next-generation sequencing was performed and revealed CDC42SE2-BRAF gene fusion, MET amplification, and CDKN2A/B deletion. Both FISH and nested RT-PCR were performed to confirm the gene fusion. The patient was treated with crizotinib for two cycles but showed no obvious benefit. The presented case adds to the spectrum of the novel, characterized solid tumors, and provides suggestions for emerging therapeutic strategies for precision medicine involving targeted kinase inhibitors.

CD30 expression and its correlation with MYC and BCL2 in de novo diffuse large B-cell lymphoma.

AIM: CD30+ diffuse large B-cell lymphoma (DLBCL) has emerged as a new immunophenotypic variant of de novo DLBCLs. However, the prevalence of CD30 positivity is variable according to different studies, and the prognostic significance of CD30 is also controversial. This study aimed to investigate the positive expression rate and prognostic impact of CD30 in de novo DLBCLs and try to find the correlated influences. METHODS: A total of 241 patients with de novo DLBCL in east China from 2008 to 2015 were included to investigate the prevalence, clinicopathological features and outcomes of CD30+ de novo DLBCLs. Immunohistochemical evaluation for CD10, CD30, BCL2, BCL6, MUM1/IRF4, MYC and Ki67, and fluorescence in situ hybridisation for MYC and BCL2 gene alterations were performed. RESULTS: Using a >0% threshold, CD30 expression was detected in approximately 10% patient with de novo DLBCL. These predominately presented with centroblastic or anaplastic morphological patterns, less frequently showing immunoblastic morphology or 'starry sky' pattern, mutually exclusive with MYC gene rearrangement, and negatively associated with BCL2 protein expression. CD30 expression was associated with a favourable prognosis of patients' outcomes. However, the multivariate analysis revealed that it was not an independent prognostic factor in de novo DLBCLs. The impact of CD30 might be influenced by the international prognostic index and the expression of MYC and BCL2 proteins. CONCLUSION: CD30+ DLBCL may be a subset of de novo DLBCLs with characteristic clinicopathological features, but the prognostic role of CD30 is limited.

Tacrolimus Reverses UVB Irradiation-Induced Epidermal Langerhans Cell Reduction by Inhibiting TNF-α Secretion in Keratinocytes via Regulation of NF-κB/p65.

Background: Topical calcineurin inhibitors including tacrolimus and pimecrolimus are used in the treatment of many inflammatory skin diseases mainly via blocking T-cell proliferation. Our previous studies found that pimecrolimus 1% cream could reverse high-dose ultraviolet B (UVB) irradiation-induced epidermal Langerhans cell (LC) reduction via inhibition of LC migration. We conducted this study to investigate the effects of topical tacrolimus 0.03% ointment on high-dose UVB-irradiated human epidermal LCs. Methods: Twenty fresh human foreskin tissues were randomly divided into four groups as follows: Control, Tacrolimus (0.03%), UVB (180 mJ/cm2), and UVB (180 mJ/cm2) + Tacrolimus (0.03%). Four time points were set as follows: 0, 18, 24, and 48 h. We collected culture medium and tissues at each time point. The percentage of CD1a+ cells in the medium was detected by means of flow cytometry. Each tissue was prepared for immunohistochemistry, real-time quantitative PCR, and western blot. HaCaT cells were cultured and divided into four groups: Control, Tacrolimus (1 µg/ml), UVB (30 mJ/cm2), and UVB (30 mJ/cm2) + Tacrolimus (1 µg/ml). The cells were incubated for 24 h and prepared for real-time quantitative PCR and western blot. Results: Topical tacrolimus significantly reversed high-dose UVB irradiation-induced epidermal LC reduction and CD1a+ cell increment in culture medium. Tacrolimus significantly inhibited UVB irradiation-induced tumor necrosis factor-α (TNF-α) and nuclear factor kappa B (NF-κB)/p65 mRNA and protein expression in HaCaT cells. Tacrolimus also significantly inhibited high-dose UVB irradiation-induced TNF-α expression in cultured tissues. Finally, TNF-α antagonist (recombinant human TNF-α receptor II: IgG Fc fusion protein) could significantly reverse UVB irradiation-induced epidermal LC reduction. Conclusion: Topical tacrolimus 0.03% could reverse UVB irradiation-induced epidermal LC reduction by inhibiting TNF-α secretion in keratinocytes via regulation of NF-κB/p65.

Simultaneous resection of left atrial myxoma and esophageal carcinoma via right thoraco-abdominal approach.

Concomitant occurrence of atrial myxoma and esophageal carcinoma is an extremely rare entity. Here we present two cases of synchronously suffered left atrial myxoma and esophageal carcinoma. Both patients underwent simultaneous resection of two tumors via the right thoraco-abdominal approach and recovered well.

Hashimoto's thyroiditis could be secondary to vitiligo: the possibility of antigen crossover and oxidative stress between the two diseases.

Autoimmune thyroid diseases (AITDs) are often accompanied by vitiligo, and the sera of patients with vitiligo often demonstrate increased frequencies of thyroid autoantibodies. In this study, we investigated the expression of melanocyte-associated antigens in tissues from patients with Hashimoto's thyroiditis (HT) without vitiligo using immunohistochemistry. Tissues of HT without vitiligo, as well as normal thyroid tissues, were both negative for the expression of NKI/beteb, gp100, tyrosinase-related protein 1 (TRP1), HMB-45 and S100, whereas they were positive for the expression of tyrosinase-related protein 2 (TRP2), lysosome-associated membrane protein 1 (LAMP1) and CD69. Tyrosinase (TYR) was only detected in tissues of HT, and levels of LAMP1 and CD69 were higher in tissues of HT than in normal thyroid tissues (p < 0.005). These results suggest the possibility of antigen crossover and oxidative stress between vitiligo and HT that might represent an immunological basis for secondary HT associated with vitiligo.

The distinct clinical features and prognosis of the CD10⁺MUM1⁺ and CD10⁻Bcl6⁻MUM1⁻ diffuse large B-cell lymphoma.

Using an immunohistochemistry (IHC) based method, diffuse large B-cell lymphoma (DLBCL) can be classified into germinal center B-cell (GCB) and non-GCB subtypes. However, the prognostic value of Hans algorithm was contradictory in the literature. Using IHC and fluorescence in situ hybridization, we analyzed the antibodies applied in Hans algorithm and other genetic factors in 601 DLBCL patients and prognostic value of Hans algorithm in 306 cases who were treated with chemoimmunotherapy. The results showed that patients with GCB subtype have better overall survival (OS) and progression-free survival (PFS) than non-GCB cases. However, to some extent, double positive (CD10(+)MUM1(+), DP) and triple negative (CD10(-)Bcl6(-)MUM(-), TN) showed different clinical characteristics and prognosis to others that were assigned to the same cell-of-origin group. The DP group showed similar OS (median OS: both not reached, P = 0.3650) and PFS (median PFS: 47.0 vs. 32.7 months, P = 0.0878) with the non-GCB group while the TN group showed similar OS (median OS: both not reached, P = 0.9278) and PFS (median PFS: both not reached, P = 0.9420) with the GCB group. In conclusion, Recognition of specific entities in Hans algorithm could help us to accurately predict outcome of the patients and choose the best clinical management for them.

[Succinate dehydrogenase deficient gastrointestinal stromal tumor: a clinicopathologic analysis of eight cases].

OBJECTIVE: To study the clinicopathologic features, diagnosis and differential diagnosis of succinate dehydrogenase (SDH) deficient gastrointestinal stromal tumors (GISTs) as a unique tumor subtype. METHODS: SDHB and SDHA immunohistochemistry was performed in 120 gastric GISTs, in addition to CD117, DOG-1, CD34, smooth muscle actin (SMA), desmin, S-100 protein, cytokeratin (CK) and Ki-67. Subset of the cases was further evaluated for the presence of mutations in CKIT exons 9, 11, 13 and 17 mutations and platelet derived growth factor receptor alpha(PDGFRA) exons 12 and 18. RESULTS: Eight of 120 (6.6%) GIST cases were found SDH-deficient including 3 male and 5 female patients (median age of 36.2 years; ranging 16 to 65 years of age). The tumors involved antrum (6 cases), lesser curvature (1 case) and fundus (1 case). Macroscopically, the dominant tumor masses varied from 3 to 10 cm in diameter with a multinodular or plexiform pattern involving the gastric wall. Microscopically,tumor cells had predominantly epithelioid morphology, with occasional mixed spindle cell nodules. Lymphovascular invasion was identified in 5 cases. Immunohistochemistry for SDHB was negative in all 8 cases, and SDHA was negative in 5 cases. All 8 SDHB negative cases also expressed CD117, DOG-1 and CD34, but were negative for SMA, desmin, S-100 and CK. All 8 cases were found to have wild-type CKIT and PDGFRA genes. Available clinical follow-up were obtained in 7 cases, ranging from 2 to 60 months (median follow-up 23.3 months), and all patient were alive. Three cases were found to have liver metastases at their first diagnosis, and one developed omental and mesenteric metastases in 17 months. CONCLUSIONS: SDH-deficient GIST is a distinct subtype of GIST, with a predilection to occur in young and female patients. Characteristic pathological findings include multinodular gastric wall involvement, epithelioid cell morphology, frequently lymphovascular invasion with occasional lymph node and liver metastases, but an overall indolent clinical behavior. Immunohistochemistry for SDHB is required for the diagnosis.

Epstein-Barr virus positive diffuse large B-cell lymphoma predict poor outcome, regardless of the age.

Epstein-Barr virus (EBV) positive diffuse large B-cell lymphoma (DLBCL) of the elderly is defined as patients older than 50 years alone. However, recent studies showed young patients with sound immune status could also be affected. In this study, we investigated the clinical features and outcomes of patients with EBV positive DLBCL in the different age groups using different EBER cut-off values. The prevalence of EBV positive DLBCL was 14.0% (35/250) and 10.4% (26/250) for EBER cut-off of 20% and 50%, respectively. With both EBER cut-off values, patients with EBV DLBCL shared many unfavorable prognostic characteristics, regardless of age. EBV positive patients, both in the elderly and young groups, showed significantly worse overall survival and progression-free survival than negative cases. Moreover, no significant differences of outcomes were identified between different age groups with EBV positive DLBCL. In conclusion, EBV positive DLBCL patients, regardless of age, shared similar poor prognostic features and showed worse outcome than negative cases. We suggest that the age criterion of EBV positive DLBCL of the elderly, and possibly the name itself, be modified in future.

MYC or BCL2 copy number aberration is a strong predictor of outcome in patients with diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL). Patients with DLBCL harboring MYC aberrations concurrent with BCL2 or/and BCL6 aberrations constitute a specific group with extremely poor outcome. In this study, we retrospectively investigated the incidence and prognosis of MYC, BCL2, and BCL6 aberrations with DLBCL patients in Chinese population. We applied fluorescence in situ hybridization and immunohistochemical analysis in 246 DLBCL patients. The results showed that patients with MYC or BCL2 copy number aberration (CNA) had significantly worse overall survival (OS) and progression-free survival (PFS) than negative cases (P < 0.0001). Patients with both MYC and BCL2 CNA had similar outcomes to those with classic double hit lymphoma or protein double expression lymphoma (MYC and BCL2/BCL6 coexpression). By multivariate analysis, MYC CNA, BCL2 CNA and double CNA were the independent worse prognostic factors. In conclusions, patients with MYC or BCL2 CNA constituted a unique group with extremely poor outcome and may require more aggressive treatment regimens.