Keratin-Positive Giant Cell-Rich Tumor: A Review and Update.

Keratin-positive giant cell-rich tumor (KPGCT) is an extremely rare and recently described mesenchymal neoplasm that occurs in both soft tissue and bone, frequently found in young women. It has locally recurrent potential if incompletely excised but low risk for metastasis. KPGCT is histologically similar to conventional giant cell tumors of soft tissue but shows the presence of keratin-positive mononuclear cells. Interestingly, KPGCT also shares some morphological features with xanthogranulomatous epithelial tumors. These two tumors have recently been shown to harbor an HMGA2-NCOR2 fusion, arguing in favor of a single entity. Surgery is the treatment of choice for localized KPGCT. Therapeutic options for advanced or metastatic disease are unknown. This review provides an overview of the current knowledge on the clinical presentation, pathogenesis, histopathology, and treatment of KPGCT. In addition, we will discuss the differential diagnosis of this emerging entity.

Giant Cell Tumor of Soft Tissue: An Updated Review.

Giant cell tumor of soft tissue (GCTST) is a locally aggressive mesenchymal neoplasm of intermediate malignancy that predominantly occurs in the superficial soft tissue of the extremities. It is histologically similar to a giant cell tumor of bone (GCTB) and shows a mixture of round to oval mononuclear cells and osteoclast-like multinucleated giant cells. Currently, immunohistochemistry plays a very limited role in the diagnosis of GCTST. Primary or secondary malignant GCTST has recently been described and tumors exhibiting high-grade histological features demonstrate higher rates of distant metastasis. GCTST lacks the H3-3A gene mutations that are identified in the vast majority of GCTBs, suggesting a different pathogenesis. Surgery is the standard treatment for localized GCTST. Incomplete surgical resection is usually followed by local recurrence. Radiation therapy may be considered when the close proximity of critical structures prevents microscopically negative surgical margins. The systemic treatment options for advanced or metastatic disease are very limited. This review provides an updated overview of the clinicoradiological features, pathogenesis, histopathology, and treatment for GCTST. In addition, we will discuss the differential diagnosis of this peculiar neoplasm.

A case of giant nipple adenoma.

BACKGROUND: Nipple adenoma is a relatively rare benign disease. Clinically, it often presents with nipple erosions, and it should be differentiated from Paget's disease. CASE PRESENTATION: The patient was a 63-year-old woman who complained of a lump in her left nipple for more than 30 years. Computed tomography performed for screening congestive heart failure suggested a left nipple mass of 40 mm in size. Needle biopsy revealed nipple adenoma, and skin biopsy was also performed to confirm the diagnosis. Nipple tumor resection was performed under local anesthesia, and we confirmed that the final diagnosis was nipple adenoma with negative margins. The patient has been free from recurrence for 2 years since the surgery. CONCLUSIONS: We have reported our experience of a case of giant nipple adenoma.

Recent Advances in the Diagnosis, Pathogenesis, and Management of Myxoinflammatory Fibroblastic Sarcoma.

Myxoinflammatory fibroblastic sarcoma (MIFS) is an infiltrative, locally aggressive fibroblastic neoplasm of intermediate malignancy that typically arises in the distal extremities of middle-aged adults. It can histologically be confused with a number of benign and malignant conditions. Recently, high-grade examples of MIFS have been described. Immunohistochemistry plays a very limited role in the diagnosis of MIFS. Several genetic alterations have been identified in MIFS, including a t(1;10)(p22;q24) translocation with TGFBR3 and/or OGA rearrangements, BRAF rearrangement, and VGLL3 amplification. Although it appears that VGLL3 amplification is the most consistent alteration, the molecular pathogenesis of MIFS remains poorly understood. A wide resection is considered the standard treatment for MIFS. Radiotherapy may be a viable option in cases with inadequate surgical margins or cases where surgery is likely to cause significant functional impairment. The systemic treatment options for advanced or metastatic disease are very limited. This review provides an updated overview of the clinicoradiological features, pathogenesis, histopathology, and treatment of MIFS.

The first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma that deteriorated after COVID-19 vaccination.

This is the first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma (EBV + MZL) with an other iatrogenic immunodeficiency-associated lymphoproliferative disorders (LPD) (methotrexate [MTX]-associated LPD) that deteriorated after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. This case had a unique immunophenotype. A 71-year-old female patient with rheumatoid arthritis receiving MTX presented with fatigue 1 week after the SARS-CoV-2 vaccination. She was hospitalized due to hepatorenal dysfunction and pancytopenia. Computed tomography revealed systemic lymphadenopathy. Her physical condition deteriorated, and the patient died. The autopsy revealed systemic lymphadenopathy comprising medium-sized atypical lymphocytes and scattered Hodgkin/Reed-Sternberg (H/RS)-like cells. An immunohistochemical examination showed that atypical lymphocytes were positive for CD79a and MUM-1 and some were positive for CD20 and IRTA-1. H/RS-like cells were immunoreactive for CD30 and CD15 and ringed by T cells. Both cell types were positive for EBV-encoded small RNA. The majority of H/RS-like cells were positive for CD20, whereas a small number of CD3-positive cells were admixed. We herein presented the first autopsy case of EBV + MZL that deteriorated after the SARS-CoV-2 vaccination.

Biology and Management of Deep-seated Atypical Lipomatous Tumor of the Extremities.

Adipocytic neoplasms are frequently encountered in clinical practice. Atypical lipomatous tumor (ALT) is a locally aggressive but non-metastasizing adipocytic neoplasm that primarily occurs in the proximal extremities of middle-aged to older adults. Histologically, ALT is divided into adipocytic (lipoma-like), sclerosing and inflammatory subtypes. The sclerosing subtype is an unfavorable prognostic factor for local recurrence. ALT is characterized by supernumerary ring and/or giant rod chromosomes. These rings and giant markers invariably contain amplified sequences originating from the long arm of chromosome 12, including the MDM2 proto-oncogene (MDM2) and cyclin-dependent kinase 4 (CDK4) gene. MDM2 and/or CDK4 nuclear immunopositivity is present in most cases. Confidently differentiating deep-seated ALT from deep-seated ordinary lipoma is often difficult on imaging. Moreover, the sclerosing subtype may mimic a higher grade liposarcoma. Detection of MDM2 amplification by fluorescence in situ hybridization would be helpful diagnostically for ALT in more difficult cases. The standard treatment for deep-seated ALT is surgery. Although there is no consensus on the best surgical approach for deep-seated ALT of the extremities, the use of marginal resection is acceptable to preserve musculoskeletal function. This review provides an overview of the current knowledge on the clinical and imaging characteristics, pathogenesis, histopathology, and management of deep-seated ALT of the extremities.

Bortezomib Increased Vascular Permeability by Decreasing Cell-Cell Junction Molecules in Human Pulmonary Microvascular Endothelial Cells.

Bortezomib (BTZ), a chemotherapeutic drug used to treat multiple myeloma, induces life-threatening side effects, including severe pulmonary toxicity. However, the mechanisms underlying these effects remain unclear. The objectives of this study were to (1) investigate whether BTZ influences vascular permeability and (2) clarify the effect of BTZ on the expression of molecules associated with cell-cell junctions using human pulmonary microvascular endothelial cells in vitro. Clinically relevant concentrations of BTZ induced limited cytotoxicity and increased the permeability of human pulmonary microvascular endothelial cell monolayers. BTZ decreased the protein expression of claudin-5, occludin, and VE-cadherin but not that of ZO-1 and ß-catenin. Additionally, BTZ decreased the mRNA expression of claudin-5, occludin, ZO-1, VE-cadherin, and ß-catenin. Our results suggest that BTZ increases the vascular permeability of the pulmonary microvascular endothelium by downregulating cell-cell junction molecules, particularly claudin-5, occludin, and VE-cadherin.

MMP-2 Regulation of Emmprin on Tumour Cells and CD73 on Fibroblasts During Tumour-Stromal Interaction.

BACKGROUND/AIM: We previously found that binding between CD73 and extracellular matrix metalloproteinase (MMP) inducer (emmprin) and suppression of CD73 in both tumour cells and fibroblasts suppressed MMP-2 production when co-cultured. However, the importance of CD73 expression in either fibroblasts or cancer cells for cancer invasion remains unknown. In this study, we used siRNA to separately down-regulate CD73 in individual cells, and then performed a 3D co-culture to investigate tumour invasion. MATERIALS AND METHODS: siRNA was used for suppression of CD73 in either fibroblasts (ST353i, HDF) or tumour cells (FU-EPS-1, A431, CRL-2095). Immunoblotting was performed for detecting MMP-2 production after CD73 suppression. 3D-co-cultures were performed for examining tumour invasion. RESULTS: CD73 suppression revealed that CD73 expression on fibroblasts and emmprin on tumour cells were important in regulating MMP-2 production, suggesting that emmprin on tumour cells does not bind CD73 at the cis-manner, but rather at the trans-manner to CD73 present on fibroblasts. CD73 suppression also reduced MMP-2 production at the transcription level and reduced tumour invasion. CONCLUSION: CD73 on fibroblasts acts as a receptor for emmprin, which forms a complex that increases MMP-2 production, possibly resulting in increased invasiveness.

Spindle Cell Lipoma and Pleomorphic Lipoma: An Update and Review.

Spindle cell lipoma (SCL) is a benign adipocytic tumor that primarily occurs in the subcutis of the posterior neck, upper back, and shoulder, particularly of middle-aged males. SCL and pleomorphic lipoma (PL) represent a morphological spectrum of one disease process. The lesion typically presents as a relatively small (<5 cm), mobile, slow-growing, painless mass. Magnetic resonance imaging reveals the lesion to be a well-defined subcutaneous mass with a mixture of adipose and non-adipose components. Intense enhancement of the non-adipose component is seen after contrast administration. Histologically, SCL is composed of variable distributions of mature adipocytes, bland spindle cells and ropey collagen bundles and PL also contains pleomorphic and multinucleated floret-like giant cells. By immunohistochemistry, the spindle and pleomorphic/floret-like giant cells of SCL/PL are diffusely positive for CD34 and show loss of nuclear RB transcriptional corepressor 1 (RB1) expression. Recent cytogenetic and molecular genetic studies have shown heterozygous deletions of 13q14, including the RB1 gene. SCL/PL can be successfully treated with simple excision, with a very low recurrence rate. Knowledge of these peculiar tumors is important because it can mimic a variety of benign and malignant soft-tissue tumors. This review provides an updated overview of the clinical, radiological, histopathological, cytogenetic, and molecular genetic features of SCL/PL.

GLUT-1 expression is helpful to distinguish myxofibrosarcoma from nodular fasciitis.

Myxofibrosarcoma (MFS) is a fibroblastic/myofibroblastic neoplasm with a variably myxoid stroma. Histologically, MFS shows a wide spectrum of cellularity, pleomorphism and proliferative activity. Because of its variable morphology and lack of discriminatory markers, MFS can be difficult to distinguish from some benign soft-tissue tumors, especially nodular fasciitis (NF). Glucose transporter 1 (GLUT-1) is expressed in a variety of malignant mesenchymal tumors. In the current study, we evaluated GLUT-1 expression to determine its value in distinguishing MFS from NF. Tissue specimens from 14 MFS cases and 16 NF cases were sectioned and stained for GLUT-1 using immunohistochemistry. The percentage of GLUT-1-positive cells was scored as follows: 0 (no staining), 1+ (1-19%), 2+ (20-50%) and 3+ (>50%). Samples with a score of 1+ were defined as GLUT1-expressing samples. GLUT-1 expression was seen in all 14 MFS cases, whereas only 6 NF cases (37.5%) were positive for GLUT-1 and were scored 1+. Notably, 2-3+ GLUT-1 expression was found in 86% of MFS cases and 0% of NF cases. Our results indicate that GLUT-1 is a highly sensitive immunohistochemical marker for MFS and may be useful for the differential diagnosis of MFS and NF.

t(1;2)-Positive Localized Tenosynovial Giant Cell Tumor With Bone Invasion.

BACKGROUND: Localized tenosynovial giant cell tumor (LTGCT) is one of the most common benign soft-tissue tumors of the foot. Although pressure erosion in the adjacent bone may be seen, intraosseous invasion of LTGCT is extremely rare. Recent molecular studies have identified the presence of pathognomonic translocation involving the colony stimulating factor 1 (CSF1) gene at 1p13. CASE REPORT: We present an unusual case of LTGCT mimicking a malignant tumor on imaging. The patient was a 16-year-old woman with no history of trauma who presented with a 2-year history of a slow-growing, painless mass in the left fourth toe. Physical examination revealed a 2-cm, elastic hard, immobile, nontender mass. Plain radiograph showed a lytic lesion with a partially sclerotic rim in the proximal phalanx of the fourth toe. Computed tomography demonstrated an expansile lesion with plantar cortical destruction. Magnetic resonance imaging revealed a nodular mass with intermediate signal intensity on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. The mass had intense contrast enhancement. Complete excision of the mass was performed, and the bone defect was repaired with calcium phosphate cement. Cytogenetic analysis revealed a t(1;2)(p13;q37) translocation as the sole anomaly. Fluorescence in situ hybridization demonstrated the presence of CSF1 rearrangements. CONCLUSION: Although extremely rare, LTGCT should be considered in the differential diagnosis of an intraosseous lesion near small joints, especially when seen in the toe.

Arthroscopic Excision of Intra-articular AHRR-NCOA2- positive Angiofibroma of Soft Tissue of the Knee: A Case Report.

BACKGROUND/AIM: Angiofibroma of soft tissue (AFST) is a rare benign soft-tissue tumor that most frequently occurs in the lower extremities. It has a characteristic genetic feature with a balanced chromosomal translocation t(5;8)(p15;q13), resulting in a fusion of aryl hydrocarbon receptor repressor (AHRR) and nuclear receptor coactivator 2 (NCOA2). CASE REPORT: A 55-year-old woman presented with a 2-year history of left knee pain and recently noticed the development of a palpable mass. Magnetic resonance imaging exhibited a well-defined intra-articular mass with iso-signal intensity relative to skeletal muscle on T1-weighted sequences, heterogeneous high signal intensity on T2-weighted sequences and avid, diffuse enhancement on contrast-enhanced fat-suppressed T1-weighted sequences. After an ultrasound-guided core needle biopsy, the lesion was successfully treated by arthroscopically-assisted complete excision. Histologically, the tumor was composed of uniform bland spindle cells in a myxoid to collagenous stroma with a prominent vascular network. Immunohistochemically, the spindle cells were diffusely positive for CD163 and CD68 and focally positive for estrogen receptor. Moreover, AHRR-NCOA2 fusion gene was detected by reverse transcription-polymerase chain reaction. There has been no clinical evidence of local recurrence at 1-year follow-up. CONCLUSION: This is the first report of the detection of an AHRR-NCOA2 gene fusion associated with intra-articular AFST. AFST should be included in the extended differential diagnosis of an intra-articular soft-tissue mass, particularly if the mass is vascular.

Trophic and immunomodulatory effects of adipose tissue derived stem cells in a preclinical murine model of endometriosis.

Endometriosis, which exhibits enigmatic pathological features such as stromal fibrosis and proliferation of ectopic epithelial cells, is known as a refractory disease. Mesenchymal stem cells modulate the fibrosis in stromal tissues through their trophic and immunomodulatory properties. To investigate the potential of stem cells in treating endometriosis, we examined the secondary morphology and molecular alterations in endometriosis-like lesions after the administration of adipose tissue-derived stem cells (ASCs) to an experimental murine model of endometriosis. The infused ASCs were found integrated in the endometriosis-like lesions. Accompanied by the suppression of stromal fibrosis and proliferation of endometriotic epithelial cells, the infusion of ASCs with stemness potential (early passage of ASCs) suppressed the growth of endometriosis-like lesions and inhibited the expression of pro-inflammatory and pro-fibrotic cytokines, whereas no significant attenuation of endometriosis-like lesions occurred after the infusion of ASCs without stemness potential (late passage of ASCs). Accordingly, the trophic and immunomodulatory properties of ASCs may regulate fibrosis in endometriosis-like lesions, suggesting that regenerative medicine could be recognized as an innovative treatment for patients with endometriosis through the accumulation of evidence of preclinical efficacy.

A case of pituitary adenoma with infiltration into the sphenoid sinus accompanied by melanocyte proliferation.

A 71-year-old woman presenting with headache and nausea was admitted to hospital. Magnetic resonance imaging revealed a tumorous lesion that surrounded the sella turcica and infiltrated the sphenoid sinus with bone destruction. The tumor was removed by nasal endoscopy. The histology was consistent with pituitary adenoma; immunohistochemistry indicated silent corticotroph adenoma with melanocyte proliferation. The possibility that melanocytes were incorporated into the tumor mass in the sphenoid sinus and underwent proliferation was evaluated by investigating the mechanisms of melanocyte proliferation associated with basic fibroblast growth factor (bFGF) and α melanocyte-stimulating hormone (αMSH). In the normal tissue, the pars intermedia and adrenocorticotropic hormone (ACTH)-producing cells were positive for αMSH. None of the control adenoma tissues were positive for bFGF or αMSH by immunostaining. In the present case, bFGF-positive cells and αMSHpositive cells were observed, suggesting that both may have been involved in melanocyte proliferation. The expression of bFGF has been linked to aggressive disease. Pituitary adenoma with melanocyte proliferation has not been previously reported. Careful follow-up is deemed necessary in the future.

Angiofibroma of soft tissue: Current status of pathology and genetics.

Angiofibroma of soft tissue (AFST) is a new soft tissue tumor entity described in the 2020 World Health Organization Classification of Soft Tissue and Bone Tumors. It most often arises in the lower extremities of middle-aged adults and pursues a benign clinical course with a low rate of non-destructive local recurrence. Histologically, the lesion consists of uniform bland spindle cells in a fibromyxoid stroma with a prominent vascular network. The vascular component forms a complex arrangement of small, thin-walled branching blood vessels. By immunohistochemistry, AFST is variably positive for epithelial membrane antigen, desmin, smooth muscle actin, CD34, CD68, CD163 and estrogen receptor. The exact etiology of AFST remains unknown, but it appears genetically distinct, with a balanced t(5;8)(p15;q13) translocation resulting in a fusion of aryl hydrocarbon receptor repressor (AHRR) and nuclear receptor coactivator 2 (NCOA2). Knowledge of this recently described entity is important because it can mimic a variety of intermediate and malignant soft tissue tumors, including solitary fibrous tumor, low-grade fibromyxoid sarcoma, myxoid liposarcoma and low-grade myxofibrosarcoma. We review AFST, with an emphasis on the diagnostic spectrum, recent molecular genetic features and the differential diagnosis.

Functional Prognosis Following Temporal Bone Chondroblastoma Resection: A Systematic Review and Case Illustration.

BACKGROUND: Chondroblastomas are rare tumors that account for <1% of all bone tumors, and 5.7% of them occur in the skull. The aim of this study was to investigate factors related to their functional prognosis by conducting a systematic review, including our own case. METHODS: A systematic review was conducted of case reports that clearly stated postoperative symptoms in temporal chondroblastomas. Tumor localization was limited to cases of the temporal bone. Cases not described in English were excluded. RESULTS: We obtained 30 articles comprising 44 cases and included our own case for a total of 45 cases. Postoperative asymptomatic cases accounted for 53.3% (24/45), and symptomatic cases accounted for 46.7% (21/45). Complications were observed in 31.1% (14/45) of cases. The main complications were facial palsy (9 cases), occlusal disorders (4 cases), and hearing loss (4 cases). The occurrence of facial palsy as a complication was considered likely. Tumor size was confirmed in 36 cases. Cases with postoperative complications were more likely to involve tumors ≥5 cm in size (77.8%, 7/9) compared with cases without complications (40.7%, 11/27). There was a significant association between rate of postoperative complications and tumor size (P = 0.061). CONCLUSIONS: As temporal chondroblastoma poses a risk of residual postoperative symptoms when the tumor grows, aggressive surgical treatment should be considered even in asymptomatic or small tumors.

Eosinophilic Granulomatosis with Polyangiitis Presenting with Myocarditis as an Initial Symptom: A Case Report and Review of the Literature.

A 66-year-old woman with a history of bronchial asthma had shortness of breath and fatigue upon mild exercise. She was diagnosed as congestive heart failure. A blood test showed eosinophilia without the presence of anti-neutrophil cytoplasmic antibody (ANCA), and a myocardial biopsy specimen revealed eosinophilic infiltration in the myocardium. Eosinophilia was improved when she was administered short-term methylprednisolone. After that, she had numbness and pain in her lower limbs with re-elevation of eosinophils. She had dysesthesia and hypalgesia in the distal part of the limbs. Sural nerve biopsy revealed axonal degeneration and thickness of the arterial wall, indicating a diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA). Two courses of steroid pulse therapy were performed, resulting in marked improvement of her sensory symptoms. ANCA-negative EGPA might be associated with myocarditis and peripheral neuropathy. A sufficient immunotherapy should have been considered to prevent rapid progression.

Multicentric glioblastoma in a 4-year-old female patient: A case report.

In the USA and Germany, pediatric glioblastoma (pGBM) makes up <3% of childhood brain tumors. Occasionally, GBM has multiple contrast lesions and is referred to as multicentric GBM. The current study present a case of a four-year-old female patient presented with headache, vomiting and consciousness disturbance. Radiologically, a neoplastic lesion of the right frontal lobe with hemorrhage, and bilateral thalamus, right temporal and left occipital neoplastic lesions were identified. The right frontal lesion was not continuous to other lesions. It was concluded that the tumor was a multicentric GBM with intra-tumoral hemorrhage. The tumor was pathologically GBM. Following surgery, the patient underwent chemotherapy and radiotherapy, but 11 months after surgery, the patient passed away. This case had features of childhood GBM and multicentric GBM and was difficult to treat.

Ubiquitin-specific Peptidase 6 (USP6)-associated Fibroblastic/Myofibroblastic Tumors: Evolving Concepts.

Ubiquitin-specific peptidase 6 (USP6) is a hominoid-specific gene residing on chromosome 17p13 and serves as a deubiquitinating enzyme with a diverse set of functions including intracellular trafficking, inflammatory signaling, cell transformation and protein turnover. USP6 rearrangements were first identified in aneurysmal bone cysts, resulting in promoter swapping and over-expression of wild type USP6. Several morphologically overlapping fibroblastic/myofibroblastic tumors are known to harbor USP6 rearrangements, including nodular fasciitis, cellular fibroma of tendon sheath, myositis ossificans and fibro-osseous pseudotumor of digits. Over the past few years, fusions involving the USP6 gene and various partner genes have been described in these neoplasms. The current World Health Organization Classification of Tumors of Soft Tissue suggests that USP6-rearranged lesions are typically benign and usually self-limited in their growth. This review provides an updated overview of the clinical, histological and molecular genetic features of USP6-associated fibroblastic/myofibroblastic tumors and discusses how these lesions should be best classified.