Targeted Next-generation Sequencing Reveals a Wide Morphologic and Immunophenotypic Spectrum of Monomorphic Epitheliotropic Intestinal T-Cell Lymphoma.

Primary intestinal T-cell lymphoma (PITL) is highly aggressive and includes celiac disease-related enteropathy-associated T-cell lymphoma (EATL), monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), and primary intestinal peripheral T-cell lymphoma, not otherwise specified (ITCL-NOS). MEITL is the most common PITL in Asia, comprising of monomorphic medium-sized cells typically expressing CD8, CD56, and cytotoxic granules. Occasional cases with intermediate features between MEITL and ITCL-NOS are difficult to be classified and warrant further investigation. We collected 54 surgically resected PITLs from Taiwan, with 80% presenting with bowel perforation. The overall outcome was poor with a median survival of 7 months. Based on histopathology (monomorphic vs. pleomorphic) and immunophenotype, we classified these cases into 4 groups: MEITL with typical immunophenotype (n=34), MEITL with atypical immunophenotype (n=5), pleomorphic PITL with MEITL-like immunophenotype (n=6), and ITCL-NOS (n=9). There was no EATL in our cohort. Targeted next-generation sequencing of the first 3 groups showed highly prevalent loss-of-function mutations for SETD2 (85%, 80%, and 83%, respectively) and frequent activating mutations for STAT5B (64%, 60%, and 50%, respectively) and JAK3 (38%, 20%, and 50%, respectively). In contrast, ITCL-NOS cases had less frequent mutations of SETD2 (56%) and STAT5B (11%) and rare JAK3 mutations (11%). Our results suggest that there is a wider morphologic and immunophenotypic spectrum of MEITL as currently defined in the 2017 WHO classification. MEITL with atypical immunophenotype and PITL with MEITL-like immunophenotype shared clinicopathologic and molecular features similar to MEITL but distinct from ITCL-NOS, indicating that such cases may be considered as immunophenotypic or histopathologic variants of MEITL.

Malignant gastrointestinal neuroectodermal tumor in head and neck: two challenging cases with diverse morphology and different considerations for differential diagnosis.

Malignant gastrointestinal neuroectodermal tumor (MGNET) is a sarcoma typically involving the gastrointestinal tract with neuroectodermal differentiation and EWSR1-ATF1/CREB1 fusions. Recently, rare MGNET cases were reported in extragastrointestinal sites. We identified 2 cases of MGNET arising in unprecedented laryngeal and intracranial locations, respectively. Both cases showed spindle and epithelioid tumor cells with amphophilic to clear cytoplasm and occasionally prominent nucleoli, arranged in solid, fascicular, and pseudoalveolar patterns. Case 1 exhibited moderate to marked nuclear atypia and focal intraepithelial component. In contrast, case 2 comprised predominantly low-grade epithelioid cells with extensive pseudopapillary structures. Both tumors showed an S100/SOX10-positive and HMB45/melan-A-negative immunoprofile as well as EWSR1-ATF1 fusion. A chief obstacle in diagnosing case 1 was the histologic and immunophenotypic resemblance to melanoma. The striking pseudopapillary architecture and the intracranial location of case 2 rendered differential diagnoses including meningioma and ependymoma. With the peculiar locations and morphology, these cases posed great diagnostic challenge.

A microvenular hemangioma with a rare expression of progesterone receptor immunocreativity and a review of the literature.

Microvenular hemangioma (MVH) is a rare benign vascular tumor with a controversial etiology, but hormone receptor alterations might be involved. We report a case of MVH in a 41-year-old Taiwanese woman who presented with a 1.5 × 1 cm violaceous plaque on left thigh that had appeared 1 year previously. She had taken oral contraceptives for several years and stopped 1 year prior to presentation. Histologically, the tumor was composed of small and compressed venous structures infiltrating in the dermis and subcutis. Immunohistochemically, the tumor cells displayed negative immunoreactivity for human herpesvirus-8 and positive immunoreactivity for smooth muscle actin and progesterone receptor (PR). Taken together with the patient's medical hormone therapy history and the evidence of PR immunoreactivity, our findings support that progesterone may be associated with the tumorigenesis of MVH.

The Hepatitis Viral Status in Patients With Hepatocellular Carcinoma: a Study of 3843 Patients From Taiwan Liver Cancer Network.

Hepatocellular carcinoma (HCC) is the leading cancer death in Taiwan. Chronic viral hepatitis infections have long been considered as the most important risk factors for HCC in Taiwan. The previously published reports were either carried out by individual investigators with small patient numbers or by large endemic studies with limited viral marker data. Through collaboration with 5 medical centers across Taiwan, Taiwan liver cancer network (TLCN) was established in 2005. All participating centers followed a standard protocol to recruit liver cancer patients along with their biosamples and clinical data. In addition, detailed viral marker analysis for hepatitis B virus (HBV) and hepatitis C virus (HCV) were also performed. This study included 3843 HCC patients with available blood samples in TLCN (recruited from November 2005 to April 2011). There were 2153 (56.02%) patients associated with HBV (HBV group); 969 (25.21%) with HCV (HCV group); 310 (8.07%) with both HBV and HCV (HBV+HCV group); and 411 (10.69%) were negative for both HBV and HCV (non-B non-C group). Two hundred two of the 2463 HBV patients (8.20%) were HBsAg(-), but HBV DNA (+). The age, gender, cirrhosis, viral titers, and viral genotypes were all significantly different between the above 4 groups of patients. The median age of the HBV group was the youngest, and the cirrhotic rate was lowest in the non-B non-C group (only 25%). This is the largest detailed viral hepatitis marker study for HCC patients in the English literatures. Our study provided novel data on the interaction of HBV and HCV in the HCC patients and also confirmed that the HCC database of TLCN is highly representative for Taiwan and an important resource for HCC research.

Primary Cutaneous Extranodal Natural Killer/T-Cell Lymphoma Misdiagnosed as Peripheral T-Cell Lymphoma: The Importance of Consultation/Referral and Inclusion of EBV In Situ Hybridization for Diagnosis.

BACKGROUND: Primary cutaneous T-cell lymphomas (CTCL) are heterogenous extranodal non-Hodgkin lymphomas including a few distinct and provisional entities. Compared with the West, Asian populations have a relatively higher frequency of nonmycosis fungoides CTCL. Primary cutaneous extranodal natural killer/T-cell lymphoma (PC-ENKTL) is distinct from other CTCL by the presence of EBV association. METHOD: In our recent retrospective Asian study of PC-ENKTL, we identified 5 cases initially misdiagnosed as various CTCL. We fully characterized these cases with immunohistochemistry, EBV in situ hybridization, and clonality study for T-cell receptor (TCR) γ-chain gene (TRG). RESULTS: The 5 patients included 3 males and 2 females with a median age of 45. All tumors were positive for EBER. Two cases were clonal for TRG gene rearrangement but without expression of ßF1 or TCR-γ (TCR-silent T-cell origin), 1 tumor expressed TCR-γ (γδ T-cell origin), and the remaining 2 were polyclonal for TRG and negative for TCR expression (NK-cell origin). On the basis of the initial diagnoses (2 as peripheral T-cell lymphoma, unspecified, 2 as primary cutaneous anaplastic large-cell lymphoma, and 1 as subcutaneous panniculitis-like T-cell lymphoma), all patients received CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy with additional radiotherapy in 3. All patients experienced persistent disease or relapse despite treatment in a mean duration of 8.8 months (range, 1 to 12 mo). CONCLUSIONS: PC-ENKTL is rare and aggressive. These cases strongly demonstrate the importance of consultation/referral to experienced hematopathologists and the inclusion of EBER in the initial diagnostic work-up for patients with nonmycosis fungoides CTCL to avoid erroneous diagnosis and subsequent inadequate treatment of the patients.

Endocrine mucin-producing sweat gland carcinoma occurring on extra-facial site: a case report.

Cutaneous endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a very rare low-grade malignant neoplasm analogous to the mammary solid-papillary carcinoma. It frequently expresses neuroendocrine markers and may show mucinous differentiation. Although the nodules are circumscribed, myoepithelial cells cannot be showed in most cases and about half of the cases are associated with invasive mucinous carcinoma. Hence, it has been suggested to be invasive and the precursor lesion of some primary cutaneous mucinous carcinomas. After being recognized as a distinct entity, all cases reported to date occurred either in the periocular region or on the cheek. Two thirds of the patients were female. Herein we present an unusual case of in situ EMPSGC on the chest wall skin of a middle-aged man.

Hypermethylation of the CDKN2A gene promoter is a frequent epigenetic change in periocular sebaceous carcinoma and is associated with younger patient age.

Periocular sebaceous carcinoma is an aggressive neoplasm with significant morbidity and mortality. Its pathogenesis is poorly understood. It is only rarely associated with Muir-Torre syndrome. Previous studies from Asian countries, have suggested that human papillomavirus (HPV) infection plays a role in the pathogenesis and overexpression of p16(INK4a), a surrogate marker of HPV infection, have also been reported. However, data from western countries seem contradictory. In order to clarify and explore the molecular and epigenetic basis of HPV, CDKN2A status and role of microsatellite instability in the development of periocular sebaceous carcinoma, 24 cases of periocular sebaceous carcinoma were analyzed for the expression of p16(INK4a) and mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) via immunohistochemistry. Nested polymerase chain reaction (PCR) and genechip HPV typing were used to detect HPV infection and decide its genotype when present. PCR amplification using a consensus primer pair was also performed to detect ß-HPV. The methylation status of CDKN2A promoter region was studied by methylation-specific polymerase chain reaction. HPV-positivity was demonstrated in only one of our cases (HPV 16), while another case showed p16(INK4a) overexpression. All cases showed preserved expression of mismatch repair proteins. CDKN2A promoter hypermethylation was noted in nearly half of our cases (11/24) and was associated with younger patient age (P = .013). Our results showed that periocular sebaceous carcinoma is rarely associated with HPV and microsatellite instability. Higher frequency of CDKN2A promoter hypermethylation in younger patients implies a significant epigenetic role in tumor development in this age group.

Generalized bullous fixed drug eruption is distinct from Stevens-Johnson syndrome/toxic epidermal necrolysis by immunohistopathological features.

BACKGROUND: Generalized bullous fixed drug eruption (GBFDE), a particular form of fixed drug eruption (FDE), is characterized by widespread blisters and erosions and can be confused with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). OBJECTIVE: We sought to analyze specific features of GBFDE and differentiate it from SJS/TEN. METHODS: We retrospectively studied patients with GBFDE and SJS/TEN during a period of 10 years. GBFDE was defined as typical FDE lesions with blisters involving at least 10% body surface area on at least 3 of 6 different anatomic sites. Clinical presentations; histopathological features; immunohistochemical patterns of cluster-of-differentiation (CD)3, CD4, CD8, CD56, Fas, Fas ligand, granzyme B, perforin, granulysin, and forkhead box P3 (Foxp3); and serum granulysin levels were compared. RESULTS: Twenty-three cases of GBFDE were collected. Patients with GBFDE had shorter latent periods, less mucosal involvement, more eosinophil infiltration, and dermal melanophages. Lesional infiltrates in GBFDE had more dermal CD4(+) cells including Foxp3(+) regulatory T cells, fewer intraepidermal CD56(+) cells, and fewer intraepidermal granulysin(+) cells. The serum level of granulysin in GBFDE was also significantly lower than in SJS/TEN. LIMITATIONS: The number of cases in this study is small. CONCLUSION: GBFDE is a distinct disease distinguishable from SJS/TEN by particular features such as granulysin, CD56, and Foxp3 expressions.

High recurrence rate of lymphadenitis due to nontuberculous mycobacteria and its association with concurrent Salmonella infection in Taiwan.

BACKGROUND: The objective of this study is to investigate the clinical characteristics of lymphadenitis due to nontuberculous mycobacteria (NTM) in Taiwan. METHODS: We retrospectively reviewed the medical records of all patients who presented to the National Taiwan University Hospital with culture-positive NTM lymphadenitis during the period 2000-2010. Patients with concurrent extranodal involvement were excluded. RESULTS: From 2000 to 2010, 15 patients with lymphadenitis caused by nontuberculous mycobacteria were identified. Most patients (80%, n = 12) were infected with rapidly growing mycobacteria. Mycobacterium abscessus was the most common infective species (n = 8). Recurrence of infection involving multiple organs occurred 2-7 years after the completion of treatment in 11 (73%) patients. Five (33.3%) patients had concurrent Salmonella infections (4 patients with bacteremia and 1 patient with empyema thoracis) during the course of the disease. CONCLUSION: In Taiwanese patients, we found a high recurrence rate of NTM lymphadenitis that was closely associated with Salmonella infections. We also noted that the clinical and epidemiological manifestations of NTM lymphadenitis in Taiwan differed from their manifestations in western countries.

EGFR-driven up-regulation of decoy receptor 3 in keratinocytes contributes to the pathogenesis of psoriasis.

Decoy receptor 3 (DcR3) is a soluble receptor of Fas ligand (FasL), LIGHT (TNFSF14) and TNF-like molecule 1A (TL1A) and plays pleiotropic roles in many inflammatory and autoimmune disorders and malignant diseases. In cutaneous biology, DcR3 is expressed in primary human epidermal keratinocytes and is upregulated in skin lesions in psoriasis, which is characterized by chronic inflammation and angiogenesis. However, the regulatory mechanisms of DcR3 over-expression in skin lesions of psoriasis are unknown. Here, we demonstrate that DcR3 can be detected in both dermal blood vessels and epidermal layers of psoriatic skin lesions. Analysis of serum samples showed that DcR3 was elevated, but FasL was downregulated in psoriatic patients compared with normal individuals. Additional cell studies revealed a central role of epidermal growth factor receptor (EGFR) in controlling the basal expression of DcR3 in keratinocytes. Activation of EGFR by epidermal growth factor (EGF) and transforming growth factor (TGF)-α strikingly upregulated DcR3 production. TNF-αenhanced DcR3 expression in both keratinocytes and endothelial cells compared with various inflammatory cytokines involved in psoriasis. Additionally, TNF-α-enhanced DcR3 expression in keratinocytes was inhibited when EGFR was knocked down or EGFR inhibitor was used. The NF-κB pathway was critically involved in the molecular mechanisms underlying the action of EGFR and inflammatory cytokines. Collectively, the novel regulatory mechanisms of DcR3 expression in psoriasis, particularly in keratinocytes and endothelial cells, provides new insight into the pathogenesis of psoriasis and may also contribute to the understanding of other diseases that involve DcR3 overexpression.

The long-term stability and biocompatibility of fluorescent nanodiamond as an in vivo contrast agent.

Nanocarbon is a promising type of biomaterial for diagnostic and therapeutic applications. Fluorescent nanodiamond (FND) containing nitrogen-vacancy centers as built-in fluorophores is a new addition to the nanocarbon family. Here, we study the long-term stability and biocompatibility of 100-nm FNDs in rats through intraperitoneal injection over 5 months and develop the potential application of this biomaterial for sentinel lymph node mapping in a mouse model. From both in vivo and ex vivo fluorescence imaging as well as transmission electron microscopy, we found that the intradermally administered FND particles can be drained from the injection sites by macrophages and selectively accumulated in the axillary lymph nodes of the treated mice. Our measurements of water consumption, fodder consumption, body weight, and organ index showed no significant difference between control and FND-treated groups of the rats. Histopathological analysis of various tissues and organs indicated that FNDs are non-toxic even when a large quantity, up to 75 mg/kg body weight, of the particles was administered intraperitoneally to the living animals. With the properties of wide-ranging biocompatibility and perfect chemical and photophysical stability, FND is well suited for use as a contrast agent for long-term in vivo imaging.

Hepatosplenic actinomycosis in an immunocompetent patient.

Hepatosplenic abscess caused by Actinomyces is rare and often misdiagnosed as malignancy. Herein, we report a case of hepatosplenic actinomycosis in a 37-year-old immunocompetent man with a 2-month clinical history of intermittent fever and upper left abdominal pain. Physical examination revealed a mildly ill-appearing man with a low-grade fever (38°C) and upper left quadrant abdominal tenderness. Abdominal sonographic examination showed the presence of a 6.3 cm × 6.5 cm heterogeneous abscess with a hypoechoic center and honeycomb appearance in an enlarged spleen (8 cm × 5 cm). Computerized tomography of the abdomen revealed a multiloculated splenic lesion, and laparotomy showed multiple hepatic nodules and a splenic abscess. Histopathological examination of the biopsy revealed filamentous branching bacilli and sulfur granules in the hepatosplenic abscess. The patient successfully underwent splenectomy accompanied by intravenous and oral penicillin treatment. Proper and prompt diagnosis of hepatosplenic actinomycosis is important because the therapeutic plan and prognosis of this pathogen are quite different from other microorganisms and malignancies.

Phenotype-genotype correlations in patients with TGFBI-linked corneal dystrophies in Taiwan.

PURPOSE: To determine the phenotype-genotype correlations in patients with corneal dystrophies associated with human transforming growth factor-ß-induced (TGFBI) mutations at the National Taiwan University Hospital. METHODS: Twenty-five affected patients from 15 families with corneal dystrophies were recruited. They underwent slit-lamp biomicroscopy and visual acuity examinations. Genomic DNA was extracted from their peripheral blood, and the exons amplified from TGFBI were sequenced. RESULTS: Eleven patients from 9 families with granular corneal dystrophy (GCD) presented with a wide spectrum of dot or fleck opacities and shared some similar clinical features. Genetic studies revealed an R124H mutation in 5 families and an R555W mutation in 4 families. A patient with GCD type 2 and an R124H mutation showed a marked increase in opacities in the laser-assisted in situ keratomileusis (LASIK) flap interface. Six patients from 3 families with superficial honeycomb opacities had an R555Q mutation. Of the 4 patients from 3 families with variant lattice line opacities, 3 from 2 families had an R124C mutation, whereas 1 from the third family had an A546D mutation. Spontaneous mutations were detected in 2 families: an R124C mutation in 1 family with lattice corneal dystrophy (LCD) type I and an A546D mutation in the other with atypical LCD. CONCLUSIONS: In most cases, TGFBI-linked corneal dystrophies had good phenotype-genotype correlations; however, some phenotypic variation was present. The most common mutations in Taiwan were R124H in GCD type 2 and R555W in GCD type 1. The R555Q mutation in Thiel-Behnke corneal dystrophy is not as rare in Taiwan as it is in other Asian countries. Sequencing of TGFBI can aid in the precise classification of these corneal dystrophies.

Human herpesvirus 8-associated lymphoma mimicking cutaneous anaplastic large T-cell lymphoma in a patient with human immunodeficiency virus infection.

Primary effusion lymphoma, a human herpesvirus 8 (HHV8)-associated lymphoma, is uncommon, and it is usually seen in human immunodeficiency virus (HIV)-infected patients. It presents as a body cavity-based lymphomatous effusion, but several cases of the so-called solid primary effusion lymphoma presenting as solid tumors without associated lymphomatous effusion have been reported. They have similar clinical, histopathological and immunophenotypical features. Most of them have a B-cell genotype. This suggests the solid variant may represent a clinicopathological spectrum of primary effusion lymphoma. We report a case of HHV8-associated lymphoma histopathologically and immunophenotypically mimicking cutaneous anaplastic large cell lymphoma. The patient was a 31-year-old HIV-seropositive man presenting with skin nodules over his right thigh. Biopsy of the nodules showed anaplastic large cells infiltrating the dermis. These malignant cells strongly expressed CD3, CD30 and CD43. Cutaneous anaplastic large T-cell lymphoma was initially diagnosed, but further tests, including immunoreactivity for HHV8 protein and clonal rearrangements of immunoglobulin genes, confirmed the diagnosis of HHV8-associated B-cell lymphoma with aberrant T-cell marker expression. This case provides an example of solid primary effusion lymphoma mimicking cutaneous anaplastic large T-cell lymphoma and highlights the importance of HHV8 immunohistochemistry and molecular tests in the diagnosis of HHV8-associated lymphoma with a cutaneous presentation.