Left ventricular non-compaction cardiomyopathy (LVNC) is a rare heart disease, with or without left ventricular dysfunction, which is characterized by a two-layer structure of the myocardium and an increased number of trabeculae. The study of familial forms of LVNC is helpful for risk prediction and genetic counseling of relatives. Here, we present a family consisting of three members with LVNC. Using a next-generation sequencing approach a combination of two (likely) pathogenic nonsense mutations DSG2-p.S363X and TBX20-p.D278X was identified in all three patients. TBX20 encodes the cardiac T-box transcription factor 20. DSG2 encodes desmoglein-2, which is part of the cardiac desmosomes and belongs to the cadherin family. Since the identified nonsense variant (DSG2-p.S363X) is localized in the extracellular domain of DSG2, we performed in vitro cell transfection experiments. These experiments revealed the absence of truncated DSG2 at the plasma membrane, supporting the pathogenic relevance of DSG2-p.S363X. In conclusion, we suggest that in the future, these findings might be helpful for genetic screening and counseling of patients with LVNC.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiac disease, involving changes in ventricular myocardial tissue and leading to fatal arrhythmias. Mutations in desmosomal genes are thought to be the main cause of ARVC. However, the exact molecular genetic etiology of the disease still remains largely inconclusive, and this along with large variabilities in clinical manifestations complicate clinical diagnostics.
We report two families (n = 20) in which a desmoglein-2 (DSG2) missense variant c.1003A > G, p.(Thr335Ala) was discovered in the index patients using next-generation sequencing panels. The presence of this variant in probands\' siblings and children was studied by Sanger sequencing. Five homozygotes and nine heterozygotes were found with the mutation. Participants were evaluated clinically where possible, and available medical records were obtained. All patients homozygous for the variant fulfilled the current diagnostic criteria for ARVC, whereas none of the heterozygous subjects had symptoms suggestive of ARVC or other cardiomyopathies.
The homozygous DSG2 variant c.1003A > G co-segregated with ARVC, indicating autosomal recessive inheritance and complete penetrance. More research is needed to establish a detailed understanding of the relevance of rare variants in ARVC associated genes, which is essential for informative genetic counseling and rational family member testing.

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In this study, we focus our interest on some peculiar infrastructural abnormalities detected in an insulinoma case. Tumor pancreatic endocrine cells proliferated detrimental to exocrine counterpart, so that extensive areas of prevalent β-tumor cells can be seen. Two phenotypes of β-tumor cells can be identified: (1) β-tumor cells with full euchromatic and nucleolated nuclei and (2) β-tumor cells with heterochromatic and shrink nuclei. Because of stroma alteration, including basement membrane, cell-extracellular matrix junctions are also compromised. The mostly striking and important finding in this report for a case of insulinoma is the high fragility of plasma membrane of both two phenotypes of β-tumor cells. Cell-cell junctions, especially desmosomal junctions are severely altered, almost missing, plasma membranes showed shedding membrane vesicles and extensive dissolutions leading to pseudo-syncytia formation. Extravasated blood cells, including inflammatory cells contribute to the dramatic and extensive destructive areas of epithelial cells as well as stroma counterpart. Moreover, also the inner cell cytomembranes exhibit abnormalities: many β-tumor cells have excessive dilatations of nuclear envelope and endoplasmic reticulum. All above severe infrastructural abnormalities, especially down regulation of cell-cell and cell-extracellular matrix adhesions and plasma membranes fragility might result in aberrant cell behavior and, consequently, much care should be taken for the postoperatory patient evolution.

Two variants of focal segmental glomerulosclerosis are known to present epithelial hypercellularity in the Bowman\'s space, namely the collapsing and the cellular types. This epithelial cell proliferation may get features of either pseudocrescent or tubular profiles. Our case of collapsing focal segmental glomerulosclerosis has been ultrastructurally investigated concerning the proliferating epithelial cell type: parietal versus visceral. Based on the cellular organelles, especially on the ubiquitous presence of desmosomes, the authors are endorsing, with ultrastructural arguments, the opinion favoring the parietal epithelial cells (PEC) as the proliferating cell type. It is also taken into consideration the eventual change of PECs phenotype in contact with the glomerular tuft components like the glomerular basement membrane.

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Recently, a surgically resected case of intraductal tubulopapillary neoplasm (ITPN) with stromal osseous and cartilaginous metaplasia was encountered. A CT scan showed calcification at the tail of the pancreas two years before the operation. In the resected specimen, macroscopically, the main pancreatic duct was dilated and filled with a whitish solid mass without mucinous material. The tumor showed mainly a solid and papillary growth pattern. The tumor cells had no evidence of acinar differentiation. The tumor cells, at the tail of the pancreas, invaded focally to surrounding pancreatic parenchyma with stromal desmoplastic and fibrosclerotic reaction and also formed nodular stromal osseous and cartilaginous metaplasia. The tumor did not invade extrapancreatic tissue and showed no lymph node metastasis. As there were no signs of chronic calcifying pancreatitis, it is hypothesized that the metaplastic stroma was formed by a stromal reaction due to the tumor growth. It is thought, therefore, that the intraducal component of the tumor had existed at least for two years. This case suggests that ITPN is a relatively indolent tumor with a better prognosis than that of other types of invasive ductal adenocarcinoma of the pancreas.

BACKGROUND: Follicular dendritic cell (FDC) sarcoma is a rare low-to-intermediate grade malignant dendritic cell neoplasm that often has an indolent clinical course. FDC sarcomas are often misdiagnosed on aspiration cytology.
METHODS: A 26-year-old woman presented with a solid, slowly growing, painless mass in her right neck for 3 months. Computed tomography revealed a 3.6-cm, well-defined homogenous solid mass located posterior to the mandible and submandibular glands. Fine needle aspiration cytology revealed many large, spindle to ovoid epithelioid cells in singles, small clusters, and syncytial sheets with moderate to abundant cytoplasm, indistinct cell borders, irregular nuclear membrane, fine to vesicular chromatin, and conspicuous nucleoli. The background contained many small mature lymphocytes intimately mixed with large epithelioid tumor cells. Tumor cells were strongly positive for CD21, CD35, CD23, and fascin. Diagnosis of FDC sarcoma was rendered; follow-up surgical resection and ultrastructural study confirmed the diagnosis. The cytogenetic study showed a normal female karyotype 46,XX.
CONCLUSIONS: Although the cytomorphology of FDC sarcoma is characteristic, a preoperative diagnosis of FDC sarcoma based on fine needle aspiration cytology is very challenging, if not impossible. Immunohistochemistry is always necessary for rendering and/or confirming the diagnosis, and ultrastructural studies are helpful.

Desmoplastic infantile ganglioglioma is a rare superficial supratentorial tumor that occurs within the first two years of life. Despite the worrisome radiological and histological appearance, the tumors are often curable following gross total resection. Tumors with similar characteristics are exceedingly rare in the noninfantile population. We present a six-year-old boy with seizures, weakness, and unsteady gait. Radiographic imaging confirmed a very large, solid and cystic mass in the right temporal-parietal region. Pathological examination demonstrated a tumor with severe desmoplasia identical to those reported as \"desmoplastic infantile ganglioglioma.\" This case adds to the limited data available for desmoplastic gangliogliomas in the noninfantile population. It is not clear, yet likely, that the noninfantile form of this neoplasm is biologically similar to the infantile form. It is also unclear whether the desmoplastic noninfantile ganglioglioma has characteristics similar to classical ganglioglioma. This rare case highlights the remarkable versatility of glioneuronal tumors in children.

We report the features in fine-needle aspiration biopsy (FNAB) of thymic basaloid carcinomas. This is a rare neoplasm, of which there are only three documented in our hospital files. To the best of our knowledge, this is the first fine-needle aspiration (FNA) report on basaloid carcinoma of the thymus. This is a tumor in which the FNA diagnosis is difficult and the differential diagnosis is broad. We describe the cytologic features encountered in the three cases, and immunohistochemical and ultrastructural findings so as to raise awareness of this entity in the differential diagnosis of thymic neoplasms on FNABs. The cases studied included three male patients, aged 73, 65, and 50, who presented with anterior mediastinal masses, with no primary tumor elsewhere. FNAB was performed on two cases, followed by thymectomy. One case, additionally, had metastasis to a cervical lymph node, and the other two were associated with thymic cysts. The diagnoses on all three cases were thymic basaloid carcinoma.