Frequent TLE1 Expression in Cutaneous Neoplasms

Expression of TLE1 in a Carcinoid Tumor of the Lung With Spindle Cell Morphology-A Potential Diagnostic Pitfall

Tumors of the lung with a spindle cell morphology require consideration of many entities in the differential diagnosis, including metastases. Ancillary immunohistochemical stains but also molecular studies are typically required to arrive at the proper diagnosis. We present a case of a 71-year-old woman with multiple lung nodules, mediastinal lymphadenopathy, and a history of uterine cancer who underwent endobronchial ultrasound-guided fine needle aspiration and biopsy of the lung and mediastinal lymph nodes. A sampling of the lung lesion showed a cytologically bland neoplasm with spindle cell morphology, lacking necrosis or brisk mitotic activity. In conjunction with the cytomorphology, strong and diffuse Transducin-like enhancer of split 1 (TLE1) reactivity in the tumor cells initially raised the diagnosis of synovial sarcoma; however, subsequent results of additional testing showed strong and diffuse expression with AE1/AE3, CK 8/18, TTF-1, synaptophysin and chromogranin and focal or negative staining with a large number of other antibodies. This warranted a diagnosis of a carcinoid tumor. This is the first report of TLE1 staining in a carcinoid tumor of the lung. Therefore, when evaluating tumors of the lung with spindle cell morphology in which the differential diagnosis may include both carcinoid tumor and synovial sarcoma, TLE1 expression should be interpreted with caution and in conjunction with an expanded immunohistochemical staining panel.

Microsecretory adenocarcinoma of the external ear canal

Microsecretory adenocarcinoma (MSA) is a recently described salivary gland tumor characterized by unique histomorphologic and immunohistochemical features as well as recurrent MEF2C::SS18 gene fusion. Since 2019, 24 cases have been reported in the literature, primarily arising in the oral cavity, with a single reported case arising in the parotid gland. Here, we present a case of MSA that arose in the external ear canal in an 89-year-old woman and was discovered during management of vertigo symptoms. Excisional biopsy of the lesion showed multiple fragments of squamous epithelium with hyperplastic changes and a distinct subepithelial infiltrating neoplasm composed of bland cells forming tubules and cords. Neoplastic cells expressed keratin, S100 protein, p63, and TLE1 and did not express p40, mammaglobin, pan-TRK, synaptophysin, or chromogranin by immunohistochemistry. SS18 gene rearrangement was shown with break-apart fluorescent in situ hybridization. Overall, the histomorphologic, immunohistochemical, and cytogenetic findings confirm a diagnosis of MSA arising in a unique extraoral location.

Primary superficial synovial sarcoma: clinical and histopathological characteristics in eight cases with molecular confirmation

BACKGROUND AND AIMS

Synovial sarcoma (SS) is a spindled cell sarcoma demonstrating varying degrees of epithelial differentiation and characterized by a pathognomonic t(X;18) translocation. SS most frequently involves deep soft tissue of the extremities in young adults. Superficial SS involving dermis and/or subcutaneous tissue is exceedingly rare.

METHODS AND RESULTS

We identified eight cases of primary superficial synovial sarcomas across three tertiary institutions. All cases were confined to the dermis/subcutis based on imaging or gross and microscopic examination. The average patient age was 36 years (range 14-50). The average tumor size was 2.4 cm (range 0.9-3.9 cm) and lesions showed classic monophasic (n = 4) or biphasic (n = 4) morphology. All tumors expressed keratin AE1/AE3 and/or epithelial membrane antigen (EMA), but were negative for CD34. The diagnosis for each case was confirmed by molecular detection of t(X;18). Six of the eight cases were treated with curative excision while the other two received additional radiotherapy. Follow-up was available for six patients (mean 68 months, range 2-108 months) and no patient experienced recurrence or metastatic disease.

CONCLUSIONS

We present the largest series to date of primary superficial SS with molecular confirmation for all cases. SS should be considered when evaluating a cutaneous monomorphic spindle cell neoplasm.

Silencing circRNA_001937 may inhibit cutaneous squamous cell carcinoma proliferation and induce apoptosis by preventing the sponging of the miRNA‑597‑3p/FOSL2 pathway

Circular RNAs (circRNAs) are reported to be aberrantly expressed and perform different functions in numerous types of tumor; however, their expression levels in cutaneous squamous cell carcinoma (CSCC) remain largely unclear. Thus, the purpose of the present study was to investigate the function of circRNA_001937 in CSCC. Differential circRNA expression profiles of CSCC were analyzed using the Arraystar Human circRNAs chip and reverse transcription-quantitative PCR (RT-qPCR); and the effects of circRNA_001937 on cell behavior, in particular its regulation over the microRNA (miRNA)-597-3p/Fos-related antigen 2 (FOSL2) pathway, was investigated using a dual-luciferase reporter assay, and verified using RT-qPCR and western blotting. circRNA_001937 expression levels were significantly increased in CSCC tissues and cell lines compared with the corresponding adjacent tissues and control cells (P<0.05). The genetic silencing of circRNA_001937 with small interfering RNA significantly inhibited cell proliferation, and induced cell apoptosis (P<0.05). circRNA_001937 was observed to directly bind to miRNA-597-3p and serve as a sponge, which indirectly increased the expression levels of FOSL2, a miRNA-597-3p target gene. In conclusion, circRNA_001937 expression was increased in CSCC and silencing circRNA_001937 gene expression may inhibit CSCC progression by sponging the miRNA-597-3p/FOSL2 pathway.

Human Cumulus Cells in Long-Term In Vitro Culture Reflect Differential Expression Profile of Genes Responsible for Planned Cell Death and Aging-A Study of New Molecular Markers

In the ovarian follicle, maturation of the oocyte increases in the presence of somatic cells called cumulus cells (CCs). These cells form a direct barrier between the oocyte and external environment. Thanks to bidirectional communication, they have a direct impact on the oocyte, its quality and development potential. Understanding the genetic profile of CCs appears to be important in elucidating the physiology of oocytes. Long-term in vitro culture of CCs collected from patients undergoing controlled ovarian stimulation during in vitro fertilization procedure was conducted. Using microarray expression analysis, transcript levels were assessed on day 1, 7, 15, and 30 of culture. Apoptosis and aging of CCs strictly influence oocyte quality and subsequently the outcome of assisted reproductive technologies (ART). Thus, particular attention was paid to the analysis of genes involved in programmed cell death, aging, and apoptosis. Due to the detailed level of expression analysis of each of the 133 analyzed genes, three groups were selected: first with significantly decreased expression during the culture; second with the statistically lowest increase in expression; and third with the highest significant increase in expression. COL3A1, SFRP4, CTGF, HTR2B, VCAM1, TNFRSF11B genes, belonging to the third group, were identified as potential carriers of information on oocyte quality.

Mesenchymal neoplasms: Is it time for cytology? New perspectives for the pre-operative diagnosis of soft tissue tumors in the molecular era

Soft tissue tumors comprise a great variety of common and rare entities with overlapping features. Their diagnosis is based on the evaluation of several histological parameters which are difficult to assess on small incisional biopsies. Useful diagnostic markers in the field of soft tissue tumors include: 1) molecular biomarkers detecting pathogenetically relevant, distinctive alterations; 2) immunohistochemical surrogate biomarkers of pathogenetically relevant, distinctive molecular alterations; 3) highly specific immunohistochemical biomarkers indicating tumor differentiation. Their introduction in clinical practice has revolutionized the pre-operative diagnosis of soft tissue tumors. Cytology has long been considered inadequate as a first-line approach in this setting. However, since the implementation of new immunohistochemical and molecular tests with high diagnostic specificity, fine needle aspiration cytology (FNAC) is starting to gain acceptance for the pre-operative assessment of soft tissue tumors. FNAC represents a versatile, poorly expensive and well-tolerated diagnostic strategy with relevant advantages over histological biopsies. Moreover, evidences suggest that, in expert hands, FNAC can also aim at a definite diagnosis, especially if a cell block is prepared, allowing the application of multiple ancillary techniques.

Trichoblastic Carcinosarcoma Arising From the Vagina: A Case Report With Comprehensive Immunophenotypic Analysis

A 54-year-old woman presented with abdominal pain. Magnetic resonance imaging revealed an upper vaginal mass with no pelvic side wall involvement, nodal, or distant metastasis. Radical hysterectomy was performed. Histology showed trichoblastic carcinoma with hair follicle structures and malignant sarcomatous and carcinomatous components. Hair follicular differentiation was confirmed by positivity to hair follicle markers (Bcl-2, TLE1, CD56/NCAM, and TDAG51) and presence of CD10-positive trichogenic stroma. The tumor involved the vaginal muscularis only (FIGO [International Federation of Gynecology and Obstetrics] stage I) and was excised with clear margins. The patient remained disease free at 3-month follow-up. This is the first case of cutaneous-type carcinosarcoma reported in the vagina, highlighting the difference in histology, immunophenotype, and behavior compared with gynecologic carcinosarcomas.

TLE1 expression fails to distinguish between synovial sarcoma, atypical fibroxanthoma, and dermatofibrosarcoma protuberans

Transducin-like enhancer of split 1 (TLE1) belongs to the Groucho/TLE/Grg family. It functions as a transcriptional corepressor and is widely used as a biomarker of synovial sarcoma (SS). Within the skin, atypical fibroxanthoma (AFX) and dermatofibrosarcoma protuberans (DFSP) often enter the histopathologic differential diagnosis. TLE1 expression has not been evaluated in these neoplasms. We examined archived tissues sections from the surgical pathology files from 10 adult patients diagnosed with AFX and 10 adult patients diagnosed with DFSP. We found nuclear staining in 10 of 10 AFX and 2 of 10 DFSP. We also noticed three patterns of staining in AFX: predominantly spindle component, predominantly epithelioid component, or mixed pattern of both epithelioid and spindle components. The group with the predominantly spindle pattern expressed the strongest nuclear TLE1 staining. In the DFSP group, one lesion demonstrated staining of epithelioid cells, with strong, diffuse nuclear TLE 1 expression, and the second lesion stained only the spindled cells, with weak nuclear TLE1 marking. In conclusion, TLE1, while a sensitive marker for SS, is not specific. A wide range of cutaneous spindle cell neoplasms also express TLE1. AFX and DFSP should be added to this list. TLE1 might be added to a diagnostic panel in this differential diagnosis.