Single-cell RNA-sequencing of stria vascularis cells in the adult Slc26a4-/- mouse

BACKGROUND

The primary pathological alterations of Pendred syndrome are endolymphatic pH acidification and luminal enlargement of the inner ear. However, the molecular contributions of specific cell types remain poorly characterized. Therefore, we aimed to identify pH regulators in pendrin-expressing cells that may contribute to the homeostasis of endolymph pH and define the cellular pathogenic mechanisms that contribute to the dysregulation of cochlear endolymph pH in Slc26a4-/- mice.

METHODS

We used single-cell RNA sequencing to identify both Slc26a4-expressing cells and Kcnj10-expressing cells in wild-type (WT, Slc26a4+/+) and Slc26a4-/- mice. Bioinformatic analysis of expression data confirmed marker genes defining the different cell types of the stria vascularis. In addition, specific findings were confirmed at the protein level by immunofluorescence.

RESULTS

We found that spindle cells, which express pendrin, contain extrinsic cellular components, a factor that enables cell-to-cell communication. In addition, the gene expression profile informed the pH of the spindle cells. Compared to WT, the transcriptional profiles in Slc26a4-/- mice showed downregulation of extracellular exosome-related genes in spindle cells. Immunofluorescence studies in spindle cells of Slc26a4-/- mice validated the increased expression of the exosome-related protein, annexin A1, and the clathrin-mediated endocytosis-related protein, adaptor protein 2.

CONCLUSION

Overall, cell isolation of stria vascularis from WT and Slc26a4-/- samples combined with cell type-specific transcriptomic analyses revealed pH-dependent alternations in spindle cells and intermediate cells, inspiring further studies into the dysfunctional role of stria vascularis cells in SLC26A4-related hearing loss.

Solitary primary pulmonary synovial sarcoma: A case report

BACKGROUND

Synovial sarcoma (SS) is an uncommon and highly malignant soft tissue sarcoma in the clinic, with primary pulmonary SS (PPSS) being extremely rare. Here, we describe the clinical characteristics, diagnosis, and treatment of a solitary PPSS case confirmed via surgical resection and fluorescence in situ hybridization (FISH).

CASE SUMMARY

A 33-year-old man was admitted because of intermittent coughing and hemoptysis for one month, with lung shadows observed for two years. Whole-body positron emission tomography-computed tomography (PET-CT) revealed a solitary mass in the upper lobe of the right lung, with uneven radioactivity uptake and a maximum standardized uptake value of 5.6. The greyish-yellow specimen obtained following thoracoscopic resection was covered with small multi-nodulated structures and consisted of soft tissue. Hematoxylin and eosin staining revealed spindle-shaped malignant tumor cells. Immunohistochemistry indicated these tumor cells were CD99 and BCL-2-positive. Furthermore, the FISH test revealed synovial sarcoma translocation genetic reassortment, which confirmed the diagnosis of SS.

CONCLUSION

PPSS is extremely rare and tends to be misdiagnosed as many primary pulmonary diseases. PET-CT, histologic analysis, and FISH tests can be used to differentiate PPSS from other diseases. Surgical resection is regularly recommended for the treatment of solitary PPSS and is helpful for improving the prognosis.

Intravascular fasciitis involving the external jugular vein and subclavian vein: A case report

BACKGROUND

Intravascular fasciitis (IVF) is a rare nodular fasciitis that often involves the layers and lumens of blood vessels; therefore, it is easily misdiagnosed as a malignant tumor with invasion into blood vessels.

CASE SUMMARY

A 13-year-old boy was admitted due to a mass on the left side of his neck. Duplex ultrasonography revealed a circular solid hypoechoic mass in the external jugular vein, and magnetic resonance imaging revealed an enhanced longitudinal mass-like lesion in the left supraclavicular fossa. Surgical treatment was arranged and completed, histopathological analysis showed a large amount of spindle cell proliferation, and immunohistochemistry showed that the spindle cells were positive for the expression of vimentin, caldesmon, and smooth muscle actin and negative for the expression of S-100 protein, desmin, CD34, and c-kit; Ki-67 staining revealed a low proliferative index (5%-10%), which confirmed the differentiation characteristics of myofibroblasts. Fluorescence in situ hybridization detected the rearrangement of USP6. IVF was subsequently diagnosed.

CONCLUSION

IVF is characterized by intraluminal, intramural and extramural involvement of small to large arteries or veins. Unless the doctor has a deep understanding of the disease or suspects that there is an initial indicator, IVF may be confused with other intravascular malignancies, leading to unnecessary radical surgery. Imaging examination combined with histopathological examination can improve the diagnostic accuracy of this disease.

Duodenal gangliocytic paraganglioma: A very rare cause for upper gastrointestinal bleeding: Case report with review of literature

INTRODUCTION

Gangliocytic paraganglioma is a rare tumors mainly arises from the second part of the duodenum. The tumor is generally benign, but some cases are associated with lymph node or distant metastasis. It must be differentiated from other tumors. The main treatment is good local surgical resection. Most patients have good prognosis after an appropriate resection.

CASE PRESENTATION

A 47-year-old male patient presented with recurrent attacks of epigastric pain and melena. The general examination revealed pallor with no jaundice. The abdomen was soft with no tenderness. There were no stigmata of chronic liver diseases. The hemoglobin level was 8 gm/dl with normal liver and renal functions. The patients received compatible blood. Endoscopy showed a large pedunculated polyp with ulceration in the second part of the duodenum just distal to ampulla of Vater. During surgery, the anterior wall of duodenum was opened, and a 4 cm pedunculated polyp was excised which was arising from the posterior wall of the duodenum just distal to the ampulla of Vater. The frozen section examination revealed a benign lesion. The final histopathology result was consistent with the diagnosis of gangliocytic paraganglioma. The patient had smooth post-operative recovery and no postoperative complications.

CONCLUSIONS

Gangliocytic paraganglioma is a rare tumor which mostly affects the second part of the duodenum. The tumor is considered benign but the possibility of the malignancy with lymphatic and distant metastases must be excluded before any surgery. The management plan must be addressed carefully and continuous follow up is recommended.

Adrenal solitary fibrous tumor: A case report

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm, originally described in the pleural cavity. It may also occur in extrapleural organs like adrenal gland. We present a case of a fifty two-year old Arab man who has been admitted in urology department for right lumbar pain. A suspect malignant adrenal mass has been detected. He underwent right adrenalectomy and histologically it was SFT. The follow-up three years after surgery is unremarkable. The prognosis of SFT after surgery is unpredictable. A long term follow-up is mandatory to detect local recurrence or distant metastasis.

Unclassified sex cord/gonadal stromal testis tumor with a "pure" spindle cell component: a case report

Unclassified sex cord/gonadal stromal tumors (SCSTs) composed predominantly of spindle cells are rare. Very few cases have been documented to date. Here, we report a case of "pure" spindle cell tumor of the left testis in a 83-year old man whose morphological and immunohistochemical findings were consistent with a diagnosis of unclassified SCST and review the literature. Owing to the spindle cell pattern, the differential diagnosis with other benign and malignant spindle cell lesions is discussed.

A primary undifferentiated pleomorphic sarcoma of the lumbosacral region harboring a LMNA-NTRK1 gene fusion with durable clinical response to crizotinib: a case report

Background

High-grade spindle cell sarcomas are a subtype of rare, undifferentiated pleomorphic sarcomas (UPSs) for which diagnosis is difficult and no specific treatment strategies have been established. The limited published data on UPSs suggest an aggressive clinical course, high rates of local recurrence and distant metastasis, and poor prognosis.

Case presentation

Here we present the unusual case of a 45-year-old male patient with a lumbosacral UPS extending into the sacrum. An initial diagnosis of a low-grade malignant spindle cell tumor was based on a tumor core biopsy. After complete extensive resection, the diagnosis of an UPS of the lumbosacral region was confirmed by excluding other types of cancers. Despite treatment with neoadjuvant radiotherapy, extensive resection, and adjuvant chemotherapy, the patient presented with multiple pulmonary metastases 3 months after surgery. The patient then began treatment with crizotinib at an oral dose of 450 mg per day, based on the detection of a LMNA-NTRK1 fusion gene in the tumor by next-generation sequencing. Over 18 months of follow-up through July 2018, the patient maintained a near-complete clinical response to crizotinib.

Conclusions

The LMNA-NTRK1 fusion was likely the molecular driver of tumorigenesis and metastasis in this patient, and the observed effectiveness of crizotinib treatment provides clinical validation of this molecular target. Molecular and cytogenetic evaluations are critical to accurate prognosis and treatment planning in cases of UPS, especially when treatment options are limited or otherwise exhausted. Molecularly targeted therapy of these rare but aggressive lesions represents a novel treatment option that may lead to fewer toxic side effects and better clinical outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4749-z) contains supplementary material, which is available to authorized users.

Foci of spindle cell proliferation in multinodular goiter of thyroid: epithelial-mesenchymal transformation or embryonic remnants?

Foci of spindle cell proliferation of the thyroid gland have been documented in adenoma and carcinoma, but not much in multinodular goiter. We report a case of spindle cell proliferation detected in multinodular goiter in a 61-year-old female. Histological examination revealed foci of solid area around the normal thyroid follicles. There were two components in this solid area; the first one was composed of epithelial cells with small bland ovoid nuclei and the second one with spindle cells with short spindle-shaped nuclei. Immunohistochemical analysis revealed that the spindle cells were positive for thyroid transcription factor (TTF)-1, Vimentin, CK (AE1/AE3), and negative for p63, etc. The cells with ovoid nuclei had more abundant CK (AE1/AE3) immunoreactivity than those with short spindle-shaped nuclei. In addition, the transition between these two cell types was clearly identified. We hypothesized that this area represented embryonic remnant of developing thyroid gland and therefore evaluated histological features of developing fetal thyroid but this lesion by no means simulated histological features of any developing stages of fetal thyroid gland. The spindle cell foci of thyroid gland could possibly arise from epithelial-mesenchymal transformation of thyroid follicular epithelium in this thyroid gland but it awaits further investigations for clarification.

Differential Diagnosis of Benign Spindle Cell Lesions

Spindle cell lesions of the breast cover a wide spectrum of diseases ranging from reactive tumor-like lesions to high-grade malignant tumors. The recognition of the benign spindle cell tumor-like lesions (nodular fasciitis; reactive spindle cell nodule after biopsy, inflammatory pseudotumor/inflammatory myofibroblastic tumor; fascicular variant of pseudoangiomatous stromal hyperplasia) and tumors (myofibroblastoma, benign fibroblastic spindle cell tumor, leiomyoma, schwannoma, spindle cell lipoma, solitary fibrous tumor, myxoma) is crucial to avoid confusion with morphologically similar but more aggressive bland-appearing spindle cell tumors, such as desmoid-type fibromatosis, low-grade (fibromatosis-like) spindle cell carcinoma, low-grade fibrosarcoma/myofibroblastic sarcoma and dermatofibrosarcoma protuberans.

Cystic Sertoli-Leydig Cell Tumour in a Postmenopausal Woman with Absent Virilising Symptoms: A Diagnostic Challenge

A 60-year-old postmenopausal woman, presented with a left ovarian cystic mass with mildly elevated CA125 levels. An intraoperative frozen section showed oedematous ovarian stroma with interspersed large aggregates of spindle shaped stromal cells. Subsequently, the excised specimen was reported as Sertoli-Leydig Cell Tumour (SLCT) of intermediate differentiation. The leydig cells were identified in the imprint smears, but were misinterpreted as luteinized cells. The lack of tubular differentiated cells in frozen section had contributed to the misdiagnosis. Immunohistochemistry (IHC) played an important diagnostic role in the absence of clinical suspicion and lack of virilising features that are classically described in association with SLCTs. This case is unusual, as the tumour was seen in a postmenopausal woman in the absence of virilising symptoms. The cytomorphological features, IHC findings and the reasons for misdiagnosis are discussed in this case report.

Immunohistochemical Diagnosis of Primary Cardiac Leiomyosarcoma in a Latin American Patient

Primary cardiac malignancies are rare entities. Although sarcomas enclosed the main group of malignant heart neoplasms, primary cardiac leiomyosarcomas are extremely rare and constitutes less than 8% of cardiac tumors. Leiomyosarcoma usually originates from the pulmonary veins and have a worm-like shaped structure. In this article, we present a case of a 40-year-old Hispanic man diagnosed with a cardiac tumor who underwent surgical resection, during pathological examination the tissue samples were consistent with a malignancy of mesenchymal origin that contained irregular bundles of spindle cells. Subsequent immunohistochemical study categorized the mass as a primary heart leiomyosarcoma with positive smooth muscle actin and muscle specific actin. As usual in this type of malignancy, patient’s clinical status declined overtime, recurrence was diagnosed two months after surgery, and four months after the procedure the patient was discharge for palliative care.

Primary thyroid spindle cell tumors: spindle cell variant of papillary thyroid carcinoma?

Primary thyroid spindle cell tumors or spindle cell component in the thyroid tumors are very rare. The spindle tumor cells were positive for thyroid papillary carcinoma markers. So these tumors were diagnosed as spindle cell variant of papillary thyroid carcinoma (PTC). To further delineate clinico-pathological features of primary thyroid spindle cell tumors and discuss differential diagnosis, we reported a 67-year-old man with a mass in the right thyroid without clinical symptom. Microscopy revealed that an encapsulated tumor with lot criss spindle cells arranged in bundles. Nuclear grooves were easy to see and rare displayed pseudoinclusions. Immunohistochemical studied showed that the spindle cells were all strong positive for TTF-1, Pax-8, thyroglobulin. Rare follicular were seen in the periphery of the tumor near the thyroid tissue. The cells formed follicular but the spindle tumor cells were positive for pan-keratins. The pathological diagnosis was primary thyroid spindle cell tumors, suspected spindle cell variant of PTC. Primary thyroid spindle cell tumors were presence and without the unified name. The further reports and more discussion were need about these tumors.

Study designs to investigate Nox1 acceleration of neoplastic progression in immortalized human epithelial cells by selection of differentiation resistant cells

To investigate the role of NADPH oxidase homolog Nox1 at an early step of cell transformation, we utilized human gingival mucosal keratinocytes immortalized by E6/E7 of human papillomavirus (HPV) type 16 (GM16) to generate progenitor cell lines either by chronic ethanol exposure or overexpression with Nox1. Among several cobblestone epithelial cell lines obtained, two distinctive spindle cell lines - FIB and NuB1 cells were more progressively transformed exhibiting tubulogenesis and anchorage-independent growth associated with increased invasiveness. These spindle cells acquired molecular markers of epithelial mesenchymal transition (EMT) including mesenchymal vimentin and simple cytokeratins (CK) 8 and 18 as well as myogenic alpha-smooth muscle actin and caldesmon. By overexpression and knockdown experiments, we showed that Nox1 on a post-translational level regulated the stability of CK18 in an ROS-, phosphorylation- and PKCepilon-dependent manner. PKCepilon may thus be used as a therapeutic target for EMT inhibition. Taken together, Nox1 accelerates neoplastic progression by regulating structural intermediate filaments leading to EMT of immortalized human gingival epithelial cells.

Primary T cell lymphoma of the small intestine with spindle cell differentiation: a case report

The vast majority of gastrointestinal lymphomas are B-cell lymphomas, often occurring in the stomach and rarely in small bowel. Due to insidious onset, atypical clinical manifestations, poor prognosis, and lack of effective diagnostic tools, primary T cell lymphoma of the small intestine has higher rates of misdiagnosis and missed diagnosis. Enteropathy-associated T-cell lymphoma with spindle cell differentiation has not been reported yet. Here we report such a case in a 60-year-old man.

Low-grade spindle-cell ameloblastic carcinoma: report of an unusual case with immunohistochemical findings and review of the literature

Spindle-cell differentiation in ameloblastic carcinoma is a rare event. Although reported by many authors, it was first described as a separate entity in 1999 by Slater under the heading "low-grade spindle-cell ameloblastic carcinoma." Here, we report a case of low-grade spindle-cell ameloblastic carcinoma arising in pre-existing unicystic ameloblastoma.The patient, a 60-year-old Indian woman, had a large irregular swelling in the left mandibular region. Histologically, the lesion was composed of a large cystic cavity with an ameloblastomatous lining and areas showing spindle-cell proliferation. The spindle cells showed hyperchromatism, nuclear pleomorphism, and scattered mitotic figures. To our knowledge, 6 cases of spindle-cell ameloblastic carcinoma have been published to date, and this case appears to be the first reporting malignant transformation with spindle-cell differentiation in unicystic ameloblastoma.