Primary cutaneous gamma/delta T-cell lymphoma in Taiwan: A series of six cases with frequent solitary presentation and relatively indolent behavior.

BACKGROUND: Primary cutaneous gamma/delta T-cell lymphoma (PCDG-TCL) is aggressive, frequently presenting as multiple plaques, tumors, and/or subcutaneous nodules. METHODS: In this study, we conducted a retrospective study in a tertiary center in Taiwan to characterize this rare tumor. RESULTS: We identified six patients. Five presented with a solitary lesion, including two with clinical impression of epidermal inclusion cyst or lipoma. Two of four evaluable cases exhibited epidermotropism, with one mimicking Pautrier microabscess. The neoplastic cells were pleomorphic and mostly medium- to large-sized. In all cases, the neoplastic cells expressed T-cell receptor (TCR)-γ and/or TCR-δ, with four co-expressing ßF1. Two of these ßF1+ cases co-expressed TCR-γ but not TCR-δ (two different clones). All were negative for Epstein-Barr virus (EBV), low stage, and treated with radiotherapy alone or combined chemotherapy and radiotherapy. In two patients, lymphoma relapsed in 3 and 7 months, respectively, and one patient died of the disease in 7 months. Four other patients were free of disease for 6 to 126 months. CONCLUSION: PCGD-TCL cases in Taiwan are more commonly solitary, frequently with indolent courses. The two currently available TCR-δ clones alone might be insufficient to detect all tumors.

Prevalence and diagnostic challenges of thyroid lymphoma: a multi-institutional study in non-Western countries.

Research on the primary thyroid lymphoma (PTL) diagnosis is limited, with only a few large sample size studies, reported from Asian countries. The aim of the present study was to clarify the current prevalence and challenges in PTL diagnosis, and recommended ancillary studies for PTL in non-Western countries. PTL (n = 153) cases were retrieved from 10 institutions in non-Western countries and analyzed. Ultrasound examination (UE) and fine needle aspiration cytology (FNAC) were used as main preoperative diagnostic tools in all participating institutions. Flow cytometry (FCM) was performed in the 5 institutions (50%). Lobectomy was the most common histological procedure to confirm the PTL diagnosis. All institutions routinely performed immuno-histochemical analysis. PTL was 0.54% of malignant thyroid tumor cases, with mucosa-associated lymphoid tissue lymphoma (MALTL) and diffuse large B-cell lymphoma (DLBCL) being 54.9% and 38.6%, respectively. Kuma Hospital, where the frequency of MALTL was highest (83.7%), routinely performed FCM using the materials obtained by FNAC. UE and FNAC sensitivities were 62.5% and 57.8%, respectively. In both UE and FNAC, sensitivity of MALTL was lower than of DLBCL. The study elucidated that the prevalence of PTL in non-Western countries was lower than previously reported. We propose that FCM should be more actively used to improve the preoperative diagnosis of MALTL. Our data predicted that the MALTL proportion will increase with improved diagnostic tools, while observation of PTL-suspected nodules without histological examination remains a viable option.

Higher bone marrow LGALS3 expression is an independent unfavorable prognostic factor for overall survival in patients with acute myeloid leukemia.

Alterations of galectin-3 expression are often seen in cancers and may contribute to tumorigenesis, cancer progression, and metastasis. The studies concerning clinical implications of galectin-3 expression in patients with acute myeloid leukemia (AML) are scarce. We investigated the expression of LGALS3, the gene encoding galectin-3, in the bone marrow (BM) mononuclear cells from an original cohort comprising 280 adults with primary non-acute promyelocytic leukemia. Higher LGALS3 expression was closely associated with older age, French-American-British M4/M5 subtypes, CD14 expression on leukemic cells, and PTPN11 mutation, but negatively correlated with CEBPA mutation and FLT3-ITD. Compared with patients with lower LGALS3 expression, those with higher expression had lower complete remission rates, higher primary refractory rates, and shorter overall survival. This result was validated in an independent validation cohort. A scoring system incorporating higher LGALS3 expression and 8 other risk factors, including age, white blood cell count, cytogenetics, and gene mutations, into survival analysis proved to be very useful to stratify patients with AML into different prognostic groups (P < .001). In conclusion, BM LGALS3 expression may serve as a new biomarker to predict clinical outcome in patients with AML, and galectin-3 may serve as a potential therapeutic target in those patients with higher expression of this protein.

Extraocular well-differentiated sebaceous tumors with overlying cutaneous horns: four tumors in three patients.

BACKGROUND: Sebaceous tumors are adnexal neoplasms showing sebocytic differentiation. They range from benign to malignant and are associated with Muir-Torre syndrome (MTS). Several clinical and histopathological features associated with MTS have been described. Sebaceous tumors with an overlying cutaneous horn are extremely rare. METHODS: Hematoxylin and eosin-stained slides were retrospectively reviewed to identify sebaceous tumors with marked hyperkeratosis, a condition that is often associated with cutaneous horns. Clinical correlation and mismatch repair protein immunohistochemical studies were then conducted. RESULTS: Four tumors from three patients were identified in our archive. Three were classified as sebaceous adenomas, and the fourth was considered as a borderline sebaceous tumor favoring well-differentiated sebaceous carcinoma. All cases showed loss of expression of mismatch repair proteins (three tumors from two patients exhibited lost expression of MSH2 and MSH6, and the fourth exhibited lost expression of MLH1 and PMS2). Additionally, one patient presented characteristic clinical manifestations of MTS, including multiple sebaceous adenomas and visceral carcinomas. CONCLUSIONS: We suggest that extraocular well-differentiated sebaceous neoplasms with overlying cutaneous horns may be an indication of underlying mismatch repair protein deficiency and potential MTS. This distinctive morphology might be an exaggerated combination of other features associated with MTS, i.e. keratoacanthoma-like architecture and extensive holocrine secretion.

Comprehensive evaluation of benign and malignant etiologies of different serous effusions with the International System for Reporting Serous Fluid Cytopathology: A multi-institutional study in Taiwan.

BACKGROUND: The International System for Reporting Serous Fluid Cytopathology (ISRSFC) was introduced globally in 2019 in response to the absence of a standardized reporting system for serous fluid cytology. This study presents experiences implementing this system across three distinct hospitals in Taiwan. METHODS: A total of 6177 serous fluid specimens in three hospitals in Taiwan between 2018 and 2020 were retrospectively reviewed and reclassified according to the ISRSFC. Cytohistological correlation and chart review were further performed to investigate etiologies and risks of malignancy (ROMs). RESULTS: Reclassification showed that 34 (0.7%) of 4838 pleural effusions were nondiagnostic (ND), 4086 (84.5%) were negative for malignancy (NFM), 201 (4.2%) were atypia of undetermined significance (AUS), 92 (1.9%) were suspicious for malignancy (SFM), and 425 (8.8%) were malignant (MAL). The 1231 ascites cases contained 13 (1.1%) ND, 1004 (81.6%) NFM, 53 (4.3%) AUS, 31 (2.5%) SFM, and 130 (10.6%) MAL specimens. In pleural effusions, the ROM was 2.9% for ND, 14.0% for NFM, 52.2% for AUS, 85.9% for SFM, and 95.1% for MAL. In ascites, it was 15.4% for ND, 19.1% for NFM, 52.8% for AUS, 83.9% for SFM, and 92.3% for MAL. In pericardial effusions, it was 0.0% for ND, 11.6% for NFM, 30.8% for AUS, 100.0% for SFM, and 95.2% for MAL. Different effusions' most common benign and malignant etiologies were also disclosed. CONCLUSIONS: These multi-institutional data have determined the diagnostic usefulness of the ISRSFC, which provides pathologists and physicians with invaluable assistance in correctly classifying effusions for further management.

DUSP22-rearranged primary cutaneous CD30-positive T-cell lymphoproliferative disorders and adult T-cell leukemia/lymphoma frequently share the LEF1+/TIA1- immunophenotype.

DUSP22 rearrangements are genetic alterations observed in a subset of systemic anaplastic large cell lymphoma (S-ALCL), primary cutaneous anaplastic large cell lymphoma (C-ALCL), and lymphomatoid papulosis (LyP). Previous investigations have shown that the LEF1+/TIA1- immunoprofile and MSC E116K mutations are highly associated with DUSP22 rearrangement in ALCL. However, the existing literature primarily focuses on S-ALCL. Our understanding of the LEF1/TIA1 immunoprofile and MSC mutation status in C-ALCL/LyP is still limited. In this study, we aimed to assess LEF1/TIA1 expression and MSC mutations in a cohort of 23 C-ALCL/LyP cases, along with a control group of histological mimickers. DUSP22 rearrangements were detected by fluorescence in situ hybridization in eight cases (6/10 C-ALCL, 2/13 LyP). We found LEF1 expression in five out of eight (63%) DUSP22-rearranged cases (3/6 C-ALCL, 2/2 LyP), and none of the 15 cases lacking DUSP22 rearrangements. Furthermore, we also found frequent LEF1 expression in adult T-cell leukemia/lymphoma (ATLL; 10 of 11, 91%) within the control group. TIA1 expression was consistently negative in all DUSP22-rearranged C-ALCL/LyP and ATLL cases tested. MCS E116K mutation was identified in one of five DUSP22-rearranged C-ALCL cases. RNA sequencing of a DUSP22-rearranged C-ALCL revealed a novel DUSP22::SNHG fusion coexisting with a CD58::WNT2B fusion. In conclusion, our findings demonstrated a lower rate of LEF1 expression in DUSP22-rearranged C-ALCL/LyP compared to previous reports that predominantly focused on S-ALCL. Moreover, we observed that the majority of ATLL cases also expressed LEF1, suggesting that the LEF1+/TIA1- immunoprofile does not differentiate DUSP22-rearranged C-ALCL/LyP from ATLL.

Cytological Features of a Metastatic Angiosarcoma in the Lymph Node Diagnosed via Liquid-Based Cytology.

Angiosarcoma is a soft tissue sarcoma of vascular origin, with more than half of the cases arising in the skin and affecting primarily the face and scalp of elderly males. Furthermore, cutaneous angiosarcoma exhibits a higher incidence of lymph node metastases than other types of sarcomas. Angiosarcomas are rarely aspirated and are occasionally encountered on cytological samples. It is a diagnostic challenge in evaluating fine needle aspiration (FNA) from a metastatic angiosarcoma without the knowledge of prior history. We present a case of scalp angiosarcoma with disease progression to erythroderma and cervical lymphadenopathy 20 months after. FNA of the cervical node revealed vasoformative features, including hemophagocytosis, formation of an intracytoplasmic lumen/vacuole, endothelial wrapping, and cell grasping. The diagnosis of nodal metastasis by angiosarcoma was confirmed with immunohistochemistry (IHC) using two vascular markers on cell block sections. Our case demonstrates the recognizable cytomorphologic clues for this rare metastatic malignancy.

Aberrant Expression of Thymosin Beta-4 Correlates With Advanced Disease and BRAF V600E Mutation in Thyroid Cancer.

Thymosin beta-4 (TMSB4X) was recently identified as a differentially expressed gene between malignant and non-malignant thyroid cells via single-cell RNA sequencing. In the present study, we aimed to study the immunostaining pattern of TMSB4X in benign and malignant thyroid neoplasms. Immunohistochemical analysis revealed that normal thyroid tissue or benign thyroid disorders exhibited undetectable immunoreactivity against TMSB4X except for positive staining of inflammatory infiltrates and stromal cells associated with autoimmune thyroid disease. By contrast, overexpression of TMSB4X was observed in a variety of thyroid malignancies, including papillary, follicular, poorly differentiated, and undifferentiated thyroid cancer. Among 141 patients with differentiated thyroid cancer, higher TMSB4X expression was associated with papillary tumor type, extrathyroidal extension, lymph node metastasis, and BRAF V600E mutation. The results were consistent with those from the public transcriptomic datasets. In summary, TMSB4X expression was aberrantly increased in various types of thyroid cancer, and higher TMSB4X expression was correlated with advanced disease characteristics. Thymosin beta-4 may be a novel downstream effector of the BRAF V600E mutation.

CRABP2 Is Associated With Thyroid Cancer Recurrence and Promotes Invasion via the Integrin/FAK/AKT Pathway.

Cellular retinoic acid-binding protein 2 (CRABP2) participates in retinoid partitioning between different nuclear receptors. Recently, we identified that CRABP2 is one of the progression-associated genes in thyroid cancer. To explore the prognostic and functional significance of CRABP2, immunohistochemical analysis was performed in thyroid tissues and neoplasms. Overexpression of CRABP2 was observed in malignant thyroid neoplasms but not in benign thyroid lesions. CRABP2 expression was an independent predictive factor for recurrence-free survival in patients with differentiated thyroid cancer. Knockdown of CRABP2 reduced the sensitivity of thyroid cancer cells to retinoic acid. Importantly, CRABP2 expression in thyroid cancer cells was associated with epithelial-mesenchymal transition properties, including anoikis resistance, migration, and invasion capacity. Furthermore, invasion promoted by CRABP2 was mediated at least partly by the integrin/focal adhesion kinase/AKT pathway. In summary, CRABP2 expression is upregulated in thyroid cancer with adverse prognostic implications. The invasion-stimulating effects appear independent of canonical retinoic acid signaling and may serve as a potential therapeutic target.

SREBP1 promotes invasive phenotypes by upregulating CYR61/CTGF via the Hippo-YAP pathway.

Aberrant lipid metabolism provides bioenergetic, biosynthetic, and redox supplies to cancer cells. Previous studies have reported differential lipid profiling in thyroid malignancies. Sterol regulatory element-binding protein 1 (SREBP1), encoded by the SREBF1 gene, is a master regulator of cellular lipid homeostasis. The clinical and functional significance of SREBP1 in thyroid cancer is not well understood. Here, we showed that SREBP1 expression is significantly upregulated in invasive thyroid cancer than in normal thyroid tissue or benign thyroid nodules. High tumoral SREBP1 expression was associated with extrathyroidal extension, advanced disease stage, and shorter disease-specific survival in patients with differentiated thyroid cancer. SREBP1 overexpression significantly increased the oxygen consumption rate, filopodia formation, and migratory and invasive capacities of thyroid cancer cells. Knockdown of SREBF1 or treatment with an SREBP1 activation inhibitor fatostatin had the opposite effect. RNA-Seq analysis showed that modulation of SREBP1 expression was accompanied by corresponding changes in the expression of epithelial-mesenchymal transition markers and CYR61/CTGF. SREBP1-facilitated cell invasion could be abrogated by treatment with a YAP inhibitor such as verteporfin or genetic silencing of CYR61 or CTGF. In summary, SREBP1 upregulation can be used as a prognostic indicator for thyroid cancer and SREBP1 overexpression is involved in cancer invasiveness, at least partly, through upregulation of CYR61/CTGF via the Hippo-YAP pathway.

C1GALT1 high expression is associated with poor survival of patients with pancreatic ductal adenocarcinoma and promotes cell invasiveness through integrin αv.

Pancreatic adenocarcinoma (PDAC) is a leading cause of cancer-related death. Altered glycosylation contributes to tumor progression and chemoresistance in many cancers. C1GALT1 is the key enzyme controlling the elongation of GalNAc-type O-glycosylation. Here we showed that C1GALT1 was overexpressed in 85% (107/126) of PDAC tumors compared with adjacent non-tumor tissues. High expression of C1GALT1 was associated with poor disease-free and overall survival (n = 99). C1GALT1 knockdown using siRNA suppressed cell viability, migration, and invasion as well as increased gemcitabine sensitivity in PDAC cells. In contrast, C1GALT1 overexpression enhanced cell migration and invasion. In subcutaneous and pancreatic orthotopic injection models, C1GALT1 knockdown decreased tumor growth and metastasis of PDAC cells in NOD/SCID mice. Mechanistically, C1GALT1 knockdown dramatically suppressed cell-extracellular matrix (ECM) adhesion, which was associated with decreased phosphorylation of FAK at Y397/Y925 and changes in O-glycans on integrins including the ß1, αv, and α5 subunits. Using functional blocking antibodies, we identified integrin αv as a critical factor in C1GALT1-mediated invasiveness of PDAC cells. In conclusion, this study not only reveals that C1GALT1 could be a potential therapeutic target for PDAC but also provides novel insights into the role of O-glycosylation in the α subunits of integrins.

Lymphovascular invasion of papillary thyroid carcinoma revisited in the era of active surveillance.

INTRODUCTION: Lymphovascular invasion (LVI) is associated with disease recurrence and compromised survival in patients with thyroid cancer. Nonetheless, LVI is not identifiable on preoperative ultrasound or cytologic assessment. We aimed to explore the clinicopathological features associated with LVI. PATIENTS AND METHODS: We conducted a retrospective review of our prospectively maintained database from 2009 to 2018. Multivariate analyses were performed to determine the associations between clinicopathological parameters and LVI. Generalized additive models were used to examine the nonlinear relationship between continuous variables and LVI. RESULTS: A total of 795 patients were included in the analysis, and 174 (22%) had LVI. Patients' age (odds ratio [OR] = 0.982), tumor size (OR = 1.466), clinical lymphadenopathy (OR = 6.975), and advanced extrathyroidal extension (OR = 2.938) were independently associated with LVI. In the subset analysis of 198 patients with available genetic information, tumor size (OR = 1.599), clinical lymph node metastasis (OR = 3.657), and TERT promoter mutation (OR = 4.726) were predictive of LVI. Among 573 patients who had no clinical lymphadenopathy or advanced extrathyroidal extension, tumor size was the only predictor of LVI. Tumor size >1.5 cm had an increased risk of LVI based on the generalized additive model plot and receiver operating characteristic curve analysis. CONCLUSION: Tumor size is positively associated with the risk of LVI in papillary thyroid cancer. To avoid delayed treatment in patients with LVI, a tumor size of 1.5 cm may be considered as the safe upper limit for active surveillance.

Granuloma With an Underlying Lymphoma: A Diagnostic Challenge and a Wider Histologic Spectrum Including Adult T-Cell Leukemia/Lymphoma.

Granulomatous reaction is not uncommon in histopathology, with various etiologies in different organs and geographic regions. Lymphoma is one of the underlying causes of granuloma; and sometimes the neoplastic cells may be masked by the granulomatous reaction. In this report, we present our experience with 7 lymphoma cases of various histologic types with coexisting granuloma to show the diagnostic challenges. In all cases, a granulomatous reaction was simultaneously present with the neoplastic cells. The 7 cases included 3 cases of adult T-cell leukemia/lymphoma in the lymph node or skin including one coexisting with mycobacterial infection, 2 cases of classical Hodgkin lymphoma involving the liver, and 1 case each of systemic Epstein-Barr virus-positive peripheral T-cell lymphoma and a hepatic inflammatory pseudotumor-like follicular dendritic cell sarcoma. Three cases were initially misdiagnosed as reactive change or mycobacterial infection instead of lymphoma, and a wrong histologic lymphoma type was diagnosed in 1 case. In this report, we showed that granulomatous reaction might mask lymphomas of various histologic types; and a diagnosis of mycobacterial infection or sarcoidosis could not exclude the possibility of an underlying lymphoma. We emphasized the importance of detailed histologic examination with the aid of ancillary studies to reach a correct diagnosis and to avoid inappropriate management of the patients. Our study also broadened the spectrum of lymphoma types coexisting with granuloma.

Primary mediastinal histiocytic sarcoma presenting as pleural effusion.

Histiocytic sarcoma (HS) is a rare malignant neoplasm showing morphological and immunophenotypic features of mature tissue histiocytes. As HS may mimic non-Hodgkin lymphoma (NHL) pathologically, before the era of immunohistochemistry, many previously reported cases were misdiagnosed NHL. Up to date, there are only a few reports delineating the cytological features in fine-needle aspiration or bronchoalveolar lavage, but not in the effusion fluid yet. Herein, we report the case of a 61-year-old male with a mediastinal tumor presenting with malignant pleural effusion. The effusion cytology showed atypical epithelioid (histiocytoid) cells, both in loose clusters and a dispersed pattern, with scanty admixed inflammatory infiltrate. Distinct from the benign histiocytes, these tumor cells exhibited evident cytological atypia, including irregular nuclear contours, significant nuclear pleomorphism, brisk mitotic figures, and apoptotic bodies in the Papanicolaou stain. With the Liu stain, most tumor cells showed abundant blue-gray cytoplasm, some with small cytoplasmic vacuoles and formation of pseudopods. Subsequent biopsies of the tumor nodules in the right lower lung and pleura showed diffuse sheets of neoplastic cells expressing CD4, CD45, CD68, and lysozyme by immunohistochemistry, confirming the diagnosis. Usually subtyping the lymphoma in the effusion fluid is not an important issue since most patients already have previously confirmed lymphoma. In rare situation, like our patient, the disease may present initially as a malignant effusion. Immunophenotyping using cell blocks and/or excisional specimens is mandatory for a definitive diagnosis.

Successful treatment of gestational trophoblastic neoplasia in the uterine cornus with laparoscopic cornuostomy and postoperative methotrexate injection.

OBJECTIVE: Management of cornual gestational trophoblastic neoplasia (GTN) has never been reported. Here, we describe the first case of cornual GTN. CASE REPORT: A 32-year-old woman was diagnosed with left cornual GTN after evacuation of a complete mole. Laparoscopic cornuostomy was performed with intramural vasopression injection and barbed sutures. Histopathology revealed hydropic chorionic villi. Complete hydatidiform mole was diagnosed, and treated with adjuvant methotrexate, to address the poor decline of ß-human chorionic gonadotropin levels during follow-up. The ß- human chorionic gonadotropin levels declined to < 1 mIU/mL 9 months after cornuostomy. She successfully conceived 16 months after cornuostomy, and underwent cesarean section at 37 gestational weeks due to concomitant severe preeclampsia. CONCLUSION: Cornual GTN can be successfully managed with laparoscopic cornuostomy and adjuvant methotrexate.

NRASQ61R immunohistochemistry detects both NRASQ61R and KRASQ61R mutations in colorectal cancer.

The NRASQ61R monoclonal antibody (clone sp174) is a mutation-specific antibody that is increasingly being used to detect the NRASQ61R mutation in melanomas. This antibody has been reported to be highly correlated with the NRASQ61R mutation status in melanomas and follicular neoplasms of the thyroid gland. However, its utility in colorectal carcinoma (CRC) has remained largely unknown. In this study, we assessed the sensitivity, specificity, and diagnostic utility of NRASQ61R immunohistochemistry in a cohort consisting of tissue sections of 113 CRCs, which were molecularly profiled for the KRAS, NRAS, and BRAF mutations. Five CRCs tested positive for NRASQ61R immunohistochemistry. Four of these CRCs exhibited the NRASQ61R mutation and one exhibited the KRASQ61R mutation. All of the other 108 colorectal carcinomas lacking the NRASQ61R or KRASQ61R mutation tested negative for NRASQ61R immunohistochemistry. In the positively stained cases, we observed a diffuse staining pattern in >90% of the tumour cells with a moderate-to-strong intensity. By contrast, the staining was essentially entirely negative in cases negative for the NRASQ61R or KRASQ61R mutations. We concluded that although it cross-reacts with the mutant KRASQ61R protein, the NRASQ61R antibody is a useful diagnostic tool that assists in the molecular testing of CRCs and facilitates patient management.