CYP1A1 immunohistochemistry is highly specific for angiofibroma of soft tissue among morphological mimics.

AIMS: Angiofibroma of soft tissue (AFST) is a benign, morphologically distinctive tumour type that harbours recurrent AHRR::NCOA2 fusions in 60-70% of cases and shows a non-specific immunophenotype, expressing EMA in roughly half of cases. The AHRR::NCOA2 fusion results in increased expression of cytochrome P450 1A1 (CYP1A1); a recent study demonstrated CYP1A1 immunohistochemistry (IHC) to be moderately sensitive and highly specific for AFST. METHODS AND RESULTS: In this study, we sought to validate these findings in a larger independent cohort of 30 AFST, as well as 215 morphological mimics, including 30 solitary fibrous tumours, 29 myxoid liposarcomas, 28 low-to-intermediate grade myxofibrosarcomas (MFS), 20 atypical spindle cell lipomatous tumours (ASCLT), 20 cellular angiofibromas, 10 cases each of spindle cell lipoma, neurofibroma, malignant peripheral nerve sheath tumour, superficial angiomyxoma, cellular myxoma, soft tissue perineurioma and deep fibrous histiocytoma, and nine cases each of low-grade fibromyxoid sarcoma and mammary-type myofibroblastoma. We found CYP1A1 IHC to be 70% sensitive for AFST, with granular cytoplasmic staining in 21 of 30 tumours, and 98% specific, with staining in only five morphological mimics: two deep fibrous histiocytomas, one MFS, one cellular angiofibroma and one ASCLT. CONCLUSIONS: These findings confirm that CYP1A1 is 70% sensitive, consistent with the prevalence of AHRR::NCOA2 fusions that up-regulate this protein, and that it is highly specific among morphological mimics.

Novel EWSR1::GFI1B gene fusion in angiofibroma of soft tissue.

AIMS: Angiofibroma of soft tissue is a benign soft tissue tumour characterised by bland spindle cells and a distinct branching vascular network. The majority of soft tissue angiofibromas harbour AHRR::NCOA2 gene fusions. Here we present three cases of EWSR1::GFI1B-fused soft tissue tumours that are morphologically most reminiscent of soft tissue angiofibroma. METHODS AND RESULTS: All three cases presented in male patients with an age range of 35-78 years (median = 54 years). Two cases presented as subcutaneous nodules on the trunk (posterior neck and chest wall); one was an intramuscular foot mass. The tumours were unencapsulated nodules with infiltrative margins ranging from 2.2 to 3.4 cm in greatest dimension. Histologically, the tumours contained uniformly bland fibroblastic spindle cells with ovoid to fusiform nuclei and delicate cytoplasmic processes embedded in a myxoid to myxocollagenous stroma. All three cases were characterised by a thin-walled, branching vascular network evenly distributed throughout the tumour. Overt cytological atypia or conspicuous mitotic activity was absent. The spindle cells had an essentially null immunophenotype. By targeted RNA sequencing, an in-frame gene fusion between EWSR1 exons 1-7 and GFI1B exons 6-11 or 7-11 was detected in all three cases. The tumours were marginally excised. For all three cases, there were no documented local recurrence or distant metastases during a limited follow-up period of 6-10 months. CONCLUSIONS: We propose that EWSR1::GFI1B may represent a novel fusion variant of soft tissue angiofibroma.

FGFR3 and FGFR4 overexpression in juvenile nasopharyngeal angiofibroma: impact of smoking history and implications for personalized management.

Lifestyle factors, including smoking, have been linked to neoplastic diseases, and reports suggest an association between smoking and overexpression of FGFR (fibroblast growth factor receptor) in certain neoplasms. This study aims to assess the expression of FGFR3 and FGFR4 genes in patients with and without a history of smoking.A total of 118 participants were recruited, including 83 Juvenile Nasopharyngeal Angiofibroma (JNA) patients and 35 healthy participants, the JNA patients were further stratified as smokers and nonsmokers. Total RNA was extracted from the blood & saliva sample by using TRIzol reagent, and quantified using a Nanodrop, and then subjected to gene expression analysis of FGFR3/4 using RT-PCR. Immunohistochemistry analysis was employed using fresh biopsies of JNA to validate the findings. All experiments were performed in triplicates and analysed using the Chi-Square test (P < 0.05). Smokers exhibited significantly lower total RNA concentrations across all sample types (P < 0.001). The study revealed significant upregulation of both FGFR3/4 genes in JNA patients (P < 0.05). Moreover, FGFR3 expression was significantly higher among smokers 66% (95% CI: 53-79%) compared to non-smokers 22% (95% CI: 18-26%). Immunohistochemistry analysis demonstrated moderate to strong staining intensity for FGFR3 among smokers. The study highlights the overexpression of FGFR3/4 genes in JNA patients, with a stronger association observed among smokers. Furthermore, medical reports indicated higher rates of recurrence and bleeding intensity among smokers. These findings emphasize the potential role of FGFR3 as a key molecular factor in JNA, particularly in the context of smoking.

Cutaneous lesions and other non-endocrine manifestations of Multiple Endocrine Neoplasia type 1 syndrome.

Background: Multiple Endocrine Neoplasia type 1 is a rare genetic syndrome mainly caused by mutations of MEN1 gene and characterized by a combination of several endocrine and non-endocrine manifestations. The objective of this study was to describe cutaneous lesions and other non-endocrine manifestations of MEN1 in a cohort of patients with familial (F) and sporadic (S) MEN1, compare the prevalence of these manifestations between the two cohorts, and investigate the correlation with MEN1 mutation status. Methods: We collected phenotypic and genotypic data of 185 patients with F-MEN1 and S-MEN1 followed from 1997 to 2022. The associations between F-MEN1 and S-MEN1 or MEN1 mutation-positive and mutation-negative patients and non-endocrine manifestations were determined using chi-square or Fisher's exact tests or multivariate exact logistic regression analyses. Results: The prevalence of angiofibromas was significantly higher in F-MEN1 than in S-MEN1 in both the whole (p < 0.001) and index case (p = 0.003) cohorts. The prevalence of lipomas was also significantly higher in F-MEN1 than in S-MEN1 (p = 0.009) and in MEN1 mutation-positive than in MEN1 mutation-negative (p = 0.01) index cases. In the whole cohort, the prevalence of lipomas was significantly higher in MEN1 mutation-positive compared to MEN1 mutation-negative patients (OR = 2.7, p = 0.02) and in F-MEN1 than in S-MEN1 (p = 0.03), only after adjustment for age. No significant differences were observed for the other non-endocrine manifestations between the two cohorts. Hibernoma and collagenoma were each present in one patient (0.5%) and meningioma and neuroblastoma in 2.7% and 0.5%, respectively. Gastric leiomyoma was present in 1.1% of the patients and uterine leiomyoma in 14% of women. Thyroid cancer, breast cancer, lung cancer, basal cell carcinoma, melanoma, and colorectal cancer were present in 4.9%, 2.7%, 1.6%, 1.6%, 2.2%, and 0.5% of the whole series, respectively. Conclusions: We found a significantly higher prevalence of angiofibromas and lipomas in F-MEN1 compared with S-MEN1 and in MEN1 mutation-positive compared to MEN1 mutation-negative patients. In patients with one major endocrine manifestation of MEN1 , the presence of cutaneous lesions might suggest the diagnosis of MEN1 and a possible indication for genetic screening.

Clinicopathologic and genetic characterization of angiofibroma of soft tissue: a study of 12 cases including two cases with AHRR::NCOA3 gene fusion.

AIMS: Angiofibroma of soft tissue (AFST) is a benign tumour characterised by prominent arborizing blood vessels throughout the lesion. Approximately two-thirds of AFST cases were reported to have AHRR::NCOA2 fusion, and only two cases have been reported to have other gene fusions: GTF2I::NCOA2 or GAB1::ABL1. Although AFST is included in fibroblastic and myofibroblastic tumours in the World Health Organization's 2020 classification, histiocytic markers, especially CD163, have been reported to be positive in almost all examined cases, and it still remains the possibility of a fibrohistiocytic nature of the tumour. Therefore, we aimed to clarify the genetic and pathological spectrum of AFST and identify whether histiocytic marker-positive cells were true neoplastic cells. METHODS AND RESULTS: We evaluated 12 AFST cases, which included 10 cases with AHRR::NCOA2 and two with AHRR::NCOA3 fusions. Pathologically, nuclear palisading, which has not been reported in AFST, was detected in two cases. Furthermore, one tumour resected by additional wide resection revealed severe infiltrative growth. Immunohistochemical analysis indicated varying levels of desmin-positive cells in nine cases, whereas CD163- and CD68-positive cells were diffusely distributed in all 12 cases. We also performed double immunofluorescence staining and immunofluorescence in situ hybridisation in four resected cases with >10% desmin-positive tumour cells. The results suggested that the CD163-positive cells differed from desmin-positive cells with AHRR::NCOA2 fusion in all four cases. CONCLUSION: Our findings suggested that AHRR::NCOA3 could be the second most frequent fusion gene, and histiocytic marker-positive cells are not genuine neoplastic cells in AFST.

CYP1A1 Is a Useful Diagnostic Marker for Angiofibroma of Soft Tissue.

Angiofibroma of soft tissue (AFST) is a recently described benign fibroblastic neoplasm composed of uniform bland spindle cell proliferation in fibrous and fibromyxoid stroma with prominent thin-walled small branching vessels. A major recurrent genetic abnormality in AFST is t(5;8)(p15;q13), which results in the rearrangement of AHRR and NCOA2 . Owing to a lack of discriminatory IHC markers and potential overlap with other mesenchymal neoplasms, it may be difficult to confirm the diagnosis of AFST in some cases. Triggered by a recent gene expression profile study of AFST, which showed the significant upregulation of AhR/AHRR/ARNT downstream genes (including CYP1A1 ), we used a mouse monoclonal antibody to explore the diagnostic significance of CYP1A1 expression in histologically confirmed AFST cases along with 224 control cases, consisting of 221 neoplastic mimickers and 3 non-neoplastic lesions. We found moderate to strong cytoplasmic expression of CYP1A1 in 13 of 16 AFST cases (sensitivity, 81.3%). In contrast, the vast majority of other examined histologic mimickers exhibited no expression of CYP1A1 (specificity, 97.3%), except for 3 myxofibrosarcomas (3/31), 2 solitary fibrous tumors (2/22), and 2 neurofibroma (1/27). Our results indicate that CYP1A1 immunohistochemistry may aid in the diagnosis of AFST by distinguishing among various kinds of tumors, particularly those harboring prominent vasculature.

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.

Sporadic facial angiofibroma and sporadic angiomyolipoma mimicking tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a genetic syndrome due to mutations in either TSC1 or TSC2, leading to the development of hamartomatous tumours at multiple body sites, including facial skin (facial angiofibroma (FAF)), brain (cortical tubers) and kidney (angiomyolipoma (AML)). In this report, we describe an individual with minimal TSC clinical features, who had 'no mutation identified' (NMI) by prior genetic testing in a clinical laboratory. Our massively parallel sequencing (MPS) analysis of multiple samples from different body sites and tumours (including blood, saliva, normal skin, AML and FAF) revealed an extraordinary situation in which FAF and AML had completely independent inactivating biallelic variants in TSC2, not present in other matched samples. This suggests that the two different lesions (AML and FAF) are not due to the same underlying germline or mosaic mutation, rather both are likely sporadic events. This case demonstrates the relevance of thorough clinical examination, high-coverage MPS of multiple tumours and matched normal tissues, and appropriate genetic counselling for individuals with marginal TSC features and possible TSC1 or TSC2 mosaicism.

Potential pathogenetic link between angiomyofibroblastoma and superficial myofibroblastoma in the female lower genital tract based on a novel MTG1-CYP2E1 fusion.

Angiomyofibroblastoma and superficial myofibroblastoma are distinctive benign mesenchymal tumors occurring in the female lower genital tract. Despite their significant overlapping clinicopathologic features, including the presence of bland-looking spindle or oval cells with myofibroblastic or myoid differentiation, the tumors have been regarded as separate entities. Although subepithelial, hormone-sensitive mesenchymal cells of the female lower genital tract are considered as their potential common progenitor cells, their potential kinship or pathogenetic similarities remain elusive. Based on the identification of a novel RNA sequencing-based MTG1-CYP2E1 fusion transcript in an angiomyofibroblastoma index case, we investigated an additional ten samples of the tumor and its site-specific histological mimics, including eight superficial myofibroblastomas, four deep angiomyxomas, four cellular angiofibromas, three fibroepithelial stromal polyps, and eight non-site-specific mesenchymal tumors occurring in the female lower genital tract. Using reverse transcription-polymerase chain reaction, we showed that the MTG1-CYP2E1 fusion transcripts were consistently detectable in angiomyofibroblastomas (5/5, 100%) and often in superficial myofibroblastomas (3/5, 60%) but were not detected in the other examined site-specific or non-site-specific mesenchymal tumors. Our immunohistochemical experiments showed that CYP2E1, an isoenzyme belonging to the cytochrome P450 superfamily, exhibited increased positivity in tumors with MTG1-CYP2E1 than was observed in fusion-negative tumors (RR = 6.56, p = 0.001). The results of our study provide further evidence supporting the assertion that angiomyofibroblastoma and superficial myofibroblastoma represent phenotypic variants of site-specific mesenchymal tumors and share a common oncogenic mechanism.

Tuberous Sclerosis.

Tuberous sclerosis is a rare autosomal dominant genetic disorder. It is characterized by the appearance of benign tumors, known as hamartomas, which can affect multiple organs, including the skin. Cutaneous manifestations are present in almost all patients; therefore, the dermatologist has a fundamental role in the history and evolution of the disease in spite of being a multisystemic disorder. Two tumor suppressor genes, CET1 and CET2, involved in tissue growth and cell proliferation, show mutation in this disease, which leads to the appearance of various benign tumors, hamartomas. Clinical characteristics are more than three hypomelanotic macules, more than three angiofibromas or face or scalp cephalic fibrotic plaque, more than two ungual fibromas, shagreen plaque, multiple retinal hamartomas, etc. Treatment is basically symptomatic, and genetic counseling is very important. This is an autosomal dominant disorder, although there is spontaneous mutation and no familial history in 65% of patients. When one of the parents is affected, genetic study is useful for prenatal diagnosis.

A report of a patient presenting with three metachronous 13q14LOH mesenchymal tumours: spindle cell lipoma, cellular angiofibroma and mammary myofibroblastoma.

Spindle cell lipoma, cellular angiofibroma and mammary myofibroblastoma are mesenchymal tumours that have overlapping morphological and immunophenotypic features. Aberrations in chromosome 13q14 have been identified as a recurrent feature. We report a unique case of a 69-year-old woman who metachronously developed all three tumours. She developed a peri-urethral and a recurrent peri-vaginal cellular angiofibroma at age 54 and 57, respectively, a spindle cell lipoma at age 62 and a mammary myofibroblastoma at age 69. Dual-colour interphase fluorescent in situ hybridisation (FISH) revealed losses of RB1 and FOXO1 (13q14LOH [loss of heterozygosity]) within neoplastic cells. There was also loss of retinoblastoma (Rb) protein expression. To our knowledge, this is the first report of these three tumours arising in the same patient. The genetic link between these tumours supports the hypothesis that they may arise from the same progenitor cells. However, further research is required to elucidate the precise pathogenetic link.

Current perspectives on the origin theory of juvenile nasopharyngeal angiofibroma.

Juvenile nasopharyngeal angiofibroma (JNA) is a histopathologically benign and highly vascular neoplasm, which is mainly seen in young adolescent men. It is a rare tumor, accounting for 0.05% of all head and neck neoplasms. The etiology of JNA has always been a controversial topic. Some researchers believe that it is a genuine tumor. Others consider that it is the result of vascular malformation caused by the non-absorption of artery residues in the first branchial arch during development, and that hormone and genetic effects are also related to its etiology. In addition, the JNA was so called because it was previously thought to originate from the nasopharynx. However, the origin site of JNA is not completely clear. Several studies emphasized that it originated from the upper lip of the sphenopalatine foramen at the junction of the sphenoid process of the palate and the pterygoid process, while others stressed that it originated from the pterygoid canal. Thus, further studies are needed for identifying the ultimate origin.

The Genetic and Molecular Determinants of Juvenile Nasopharyngeal Angiofibroma: A Systematic Review.

OBJECTIVE: Juvenile nasopharyngeal angiofibroma (JNA) is a rare vascular tumor of unknown etiology. Studies investigating the molecular and genetic determinants of JNA are limited by small sample size and inconsistent approaches. The purpose of this study is to examine all eligible JNA studies in aggregate, applying qualitative analysis to highlight areas of particular relevance, including potential targets for therapeutic intervention. METHODS: The PubMed, MEDLINE, Embase, Web of Science, Cochrane, and CINAHL databases were screened with inclusion and exclusion criteria applied to all citations. Manuscripts investigating the genetic determinants, histopathogenesis, and heritability of juvenile nasopharyngeal angiofibroma were included. Non-English studies, case reports, and articles focusing on clinical management without original data were excluded. Full text articles were obtained. A qualitative synthesis of data was performed. RESULTS: A total of 59 articles met criteria for inclusion. These were divided into 6 categories based on the primary topic or target discussed, (1) steroid hormone receptors, (2) chromosomal abnormalities, (3) growth factors, (4) genetic targets, (5) molecular targets, (6) Wnt cell signaling, and (7) studies that overlapped multiple of the aforementioned categories. Although relatively low n values prevent definitive conclusions to be drawn, a predominance of certain molecular targets such as vascular endothelial growth factor (VEGF) and Wnt/ß-catenin pathway intermediaries is apparent. CONCLUSIONS: Although the etiology of JNA remains elusive, contemporary molecular genetic investigation holds promise for risk stratification and could form the basis of a modernized staging system. A multicenter clinical registry and linked tissue bank would further promote the search for JNA specific biomarkers.

Tuberous sclerosis in a patient from Nigeria.

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome characterized by mostly benign tumors of the brain, skin, heart, kidney, and eye. Aberrations in the genes TSC1 and TSC2 which encode hamartin and tuberin, respectively, cause TSC. Because disease manifestations develop over time, early diagnosis and intervention are imperative for patients. TSC is not well described in patients from sub-Saharan Africa or of black African ancestry. Here, we report on a 4-year-old Nigerian boy with skin lesions and cardiac anomalies associated with TSC. Furthermore, we note that in areas with limited resources for genetic diagnoses, the common skin manifestations found in TSC may be especially useful clinical markers.

Familial Angiofibrohistiocytic Hamartoma Syndrome.

A 27-year-old Hispanic man presented with multiple papules and nodules measuring up to 10 cm in diameter. These lesions were widespread (Figure 1), but not on mucosal epithelium. At birth, the patient had had multiple hypopigmented macules that had progressed to papules and nodules over time. Dermatoscopic examination of these papules and nodules showed prominent capillaries. New lesions were constantly developing but were slow-growing. Other family members had similar lesions, including the patient's three brothers, father, paternal aunt, and a 3-year-old niece (daughter of the 2nd eldest brother), although not as extensively as in this patient. The paternal grandparents were not affected (Figure 2). As the patient had been raised in rural Mexico with limited financial resources, access to health care was limited, so the condition had been left undiagnosed and untreated for most of the patient's life.

[Angiofibroma of soft tissue: a clinicopathologic analysis of 24 cases].

Objective: To investigate the clinicopathologic and genetic features, pathologic diagnosis and differential diagnosis of angiofibroma of soft tissue(AFST). Methods: The clinicopathologic characteristics of 24 cases diagnosed at Fudan University Shanghai Cancer Center from 2011 to 2017 were analyzed; immunohistochemical staining and interphase fluorescence in situ hybridization (FISH) were performed, and the literatures were also reviewed. Results: There were 15 male and 9 female (male∶female=1.7∶1.0) patients with age of onset ranging from 8 to 68 years (mean, 45 years). Fourteen cases occurred in extremities, including upper limbs (n=3) and lower limbs (n=11); seven cases were in the trunk, and 1 case each was in the temporal region, retroperitoneum and liver, respectively. Clinically, the tumors usually presented as a slowly growing painless mass. Tumor sizes ranged from 0.8 to 14 cm (mean 4.6 cm). Microscopically, most lesions were well-circumscribed, with fibrous capsules. Few cases infiltrated the surrounding fibrofatty tissue focally. The tumors were mainly composed of sparse short spindle cells and numerous small, branching, thin-walled blood vessels distributed in amyxoid, fibromyxoid or collagenous matrix, often accompanied by medium-sized, round or irregular and ecstatic vessels at the tumor periphery.By immunohistochemistry, all tested cases expressed vimentin (5/5), and showed variable positivity for EMA (2/4), ER (1/2), PR (2/3), α-SMA (1/18)and desmin (1/10). Ki-67 proliferation index were all less than 5%. CD34, CD31 and ERG staining clearly outlined the contours of blood vessels in the stroma. Four cases were tested for NCOA2 gene rearrangement by FISH, of which three were positive. Follow-up data was available in 17 patients (range, 3 to 69 months; mean, 30 months) were all free of disease. Conclusions: Soft tissue angiofibroma is a benign fibroblastic neoplasm characterized by a prominent and complex vasculature set in a myxoid-to-collagenous stroma, and cytogenetically a distinctive NCOA2 gene rearrangement. Caution should be exercised for the possibility of potentially misinterpretation of AFST as vascular tumors and other myxoid soft tissue tumors.

Cutaneous Manifestations of Tuberous Sclerosis.

Dear Editor, Tuberous sclerosis (TS) is an autosomal dominant multisystem disease, which occurs due to genetically determined hyperplasia of ectodermal and mesodermal cells. Clinical manifestations present on the skin and in the nervous system, kidneys, heart, and other organs. Recent studies estimate the incidence of TS at 1/6000 to 1/10,000 live births, and a prevalence in the general population of approximately 1 in 20,000 (1). There are two different genetic loci responsible for TS: 9q34 (TSC1-hamartin) and 16p13.3 (TSC2-tuberin) (2). Cutaneous manifestations occur in about 96% of patients (3). Neurological disorders occur in 50% of patients in the form of seizures and motor and psychomotor symptomatology (4). A 19-year-old male patient was hospitalized for clinical and diagnostic evaluation in February 2016 year in Clinic for Nephrology, Clinical Center of Montenegro, Podgorica, Montenegro. Polycystic kidney changes were verified by ultrasound when the patient was three years old, with the presence of several calcified nodules in lateral ventricles and supraventricularly in the brain as well as the existence of several hypopigmented maculae on the skin. During the last hospitalization in February 2016, the following tests were performed: cranial magnet resonance imaging (MRI) findings showed the existence of visible changes in the signal in the form of ectopic tuber tissue in the region of the cortex and subcortical white matter of the brain, but without neurological and psychomotor abnormalities; ultrasound of the urinary tract showed that both kidneys were enlarged with multiple cysts, with dominant cysts at the lower pole of the right kidney with a size of 55 mm and at the upper pole of the left kidney, approximately 40 mm. Reduced functional capacity of kidneys was found on dynamic scintigraphy, slightly more in the left kidney (41%) compared with the right (59%). Electroencephalography, X-ray of the lungs and heart, and echocardiography were also performed, but without any pathological findings. Dermatological examination found numerous fibroma up to 0.5 cm in diameter, the largest located nasolabially, periorally, and on the chin skin (Figure 1) at the age of seven, whereas a fibroma and several white maculae were present from birth on the skin of the forehead. They were now also present on the skin of the trunk and on the upper and lower extremities (Figure 2), accompanied by surrounding minor changes in the form of confetti-like maculae. A subungual fibroma was present on the third finger of the right hand. Collagen nevus (shagreen patch) (5), i.e. a subepidermal fibrosis as a mildly elevated, palm-sized area is also characteristic of TS, which is described in literature, in most cases in the lumbosacral region. In our case, such a fibrosis about 3 cm in diameter, and with the consistency of an orange peel, was discovered on the right shoulder. Subungual fibromas (Koenen tumors) (6), which can develop in adolescence, were present in our patient on the third finger of the right hand. The diagnosis of TS was established based on genetic testing, physical examination, ultrasound-verified polycystic kidney disease and reduced global renal functions, intracranial MRI, many hypomelanotic changes, and angiofibromas found with dermatological examination (7). There is no specific therapeutic approach for TS, and the treatment is symptomatic. Angiofibromas of the skin can be removed by dermabrasion or laser. Recent data show a good therapeutic effect of applying 0.1% rapamycin (8), which leads to a reduction of angiofibromas in patients with TS. On dermatological follow up after five weeks of application of tacrolimus, angiofibromas of the face were in regression. Some studies suggest the simultaneous topical applications of both of those drugs (9). In adolescents and adults of reproductive age, genetic counseling is recommended (10).

Differential Gene Expression and Pathway Analysis in Juvenile Nasopharyngeal Angiofibroma Using RNA Sequencing.

Juvenile nasopharyngeal angiofibroma (JNA) is a highly vascularized and locally aggressive tumor that typically presents in adolescent males. The molecular biology of this tumor remains understudied. We sought to identify differentially expressed genes in the JNA transcriptome through messenger RNA sequencing of primary fibroblasts from 2 tumor explants and tonsil tissue from tumor-free subjects. In total, 1088 significant, differentially expressed genes were identified with 749 upregulated and 339 downregulated. Pathway analysis identified a number of activated signaling pathways, most notably, the vascular endothelial growth factor (VEGF) pathway (adjusted overlap P = .03). VEGF-A showed a 4.4-fold upregulation in JNA samples. In addition, the angiogenic receptor, fibroblast growth factor receptor 2 (FGFR2), was not present in tumor-free samples but increased in JNA. We validate these findings with immunohistochemistry, demonstrating upregulation of VEGF and FGFR2 in patient sections. Inhibition of the VEGF or FGFR signaling axes may have therapeutic potential in the treatment of JNA.