Cytoplasmic Fibrils Research Articles

Dynamic Localization of Paraspeckle Components under Osmotic Stress.

Paraspeckles are nuclear condensates formed by NEAT1_2 lncRNA and different RNA-binding proteins. In general, these membraneless organelles function in the regulation of gene expression and translation and in miRNA processing, and in doing this, they regulate cellular homeostasis and mediate pro-survival in the cell. Despite evidence showing the importance of paraspeckles in the stress response, the dynamics of paraspeckles and their components under conditions of osmotic stress remain unknown. We exposed HEK293T cells to sorbitol and examined NEAT1_2 expression using real-time PCR. Localization and quantification of the main paraspeckle components, NEAT1_2, PSPC1, NONO, and SFPQ, in different cellular compartments was performed using smFISH and immunofluorescence. Our findings showed a significant decrease in total NEAT1_2 expression in cells after osmotic stress. Sorbitol shifted the subcellular localization of NEAT1_2, PSPC1, NONO, and SFPQ from the nucleus to the cytoplasm and decreased the number and size of NEAT1_2 foci in the nucleus. PSPC1 formed immunoreactive cytoplasmic fibrils under conditions of osmotic stress, which slowly disassembled under recovery. Our study deepens the paraspeckle dynamics in response to stress, suggesting a novel role for NEAT1_2 in the cytoplasm in osmotic stress and physiological conditions.

Sarcomas With RAD51B Fusions Are Associated With a Heterogeneous Phenotype

RAD51B-rearranged sarcomas are rare neoplasms that exhibit a heterogeneous morphology. To date, 6 cases have been reported, all involving the uterus, including 4 perivascular epithelioid cell tumors (PEComas) and 2 leiomyosarcomas (LMS). In this study, we describe the morphologic, immunohistochemical, and molecular features of 8 additional sarcomas with RAD51B rearrangement, including the first extrauterine example. All patients were women with a median age of 57 years at presentation. Seven tumors originated in the uterus, and one in the lower extremity soft tissue, with a median tumor size of 12 cm. Histologically, 4 tumors showed predominantly spindle cell morphology with eosinophilic fibrillary cytoplasm, with or without nuclear pleomorphism, whereas 2 tumors exhibited pleomorphic epithelioid cells, featuring clear to eosinophilic, granular cytoplasm. Two neoplasms exhibited undifferentiated cytomorphology, including one with uniform small blue round cells. All tumors showed high-grade cytologic atypia and high mitotic activity (median: 30/10 high-power fields), whereas coagulative necrosis was noted in 6 cases and lymphovascular invasion in 2. By immunohistochemistry, 2 showed myoid and melanocytic markers in keeping with PEComa, whereas 4 cases were only positive for smooth muscle markers consistent with LMS (including 3 myxoid). The remaining 2 cases had a nonspecific immunoprofile. Five cases tested by targeted RNA sequencing (Archer FusionPlex, Illumina TruSight) showed different fusion partners (HMGA2, PDDC1, and CEP170). RAD51B rearrangements were identified by FISH in the remaining 3 cases. Targeted DNA sequencing in 2 cases was negative for TSC gene alterations. Clinical outcome, available in 5 patients (median follow-up, 19 months), revealed 3 local recurrences, 2 lung metastases, and 4 deaths due to disease. Our results expand the spectrum of sarcomas with RAD51B fusions, demonstrating variable clinical presentations, morphologic spectrum, and fusion partners. These tumors have a predilection for a uterine location, with either LMS, PEComa, or undifferentiated phenotypes, and are associated with an aggressive clinical course.

The frequency of co-positivity of anti-smooth muscle antibody and anti-nuclear antibodies and their contribution to the diagnosis of autoimmune hepatitis

Aim: Autoimmune hepatitis (AIH) is a chronic disease observed especially in women. The International Autoimmune Hepatitis Group recommends scoring systems for diagnosis using clinical and laboratory data. All scoring systems gave points to autoantibodies as anti-nuclear antibody (ANA) and anti-smooth muscle antibody (SMA) positivity. This study investigates the impact of the co-positivity of the ANA and SMA antibodies on the autoimmune hepatitis diagnosis.
 Material and Method: We monitored 78 autoimmune liver disease (autoimmune hepatitis, AIH) suspected patients with positive SMA antibody and then further tested for ANA between 2014 and2021. SMA test was screened at 1/40 and 1/100 titers and patients who were positive were taken to further dilution. The ANA test was screened at a titer of 1/40 and 1/160, a positive result was found to be repeated with advanced dilutions. All patients’ autoantibody scores of simplified AIH diagnostic system were calculated.
 Results: Seventy eight patients with positive SMA antibodies screened for ANA test with 1/40 and 1/160 titer, only 2 patients was found to be negative. The most frequently observed ANA pattern is cytoplasmic linear fibrils (68% ). The 95% ANA positive results was examined at a screening titer of 1/160. The 95% SMA positive results was found at a screening titer of 1/100. The autoantibody scores of 76 patients were +2, patient’s scores were +1.
 Conclusion: SMA antibody positivity is accompanied by a high rate of ANA antibody positivity but the co-positivity didn’t effect diagnostic score systems. On the other the co-positivity could be a sign of another associated autoimmune diseases.

Multiple leiomyosarcomatous lesions arising from the mesentery in a young female: An unusual rare case presentation

Rationale: Primary mesenteric leiomyosarcoma is a very rare finding. It is seen predominantly in the seventh decade and is very rare in the young. Fine needle aspiration cytology is the initial diagnostic procedure in soft tissue lesions, followed by excision biopsy. Patient Concerns: Herein, we present a rare case of primary multiple mesenteric leiomyosarcoma in a 19 year old female, who presented with abdominal lump and pain since the last 4 months. Diagnosis: CT scan of abdomen showed multiple large multiloculated masses in the sub-hepatic space and sub-diaphragmatic region, which seemed to be arising from the mesentery. The uterus and cervix were normal. Fine needle aspiration cytology of the mass revealed fascicles of spindled cells with elongated, blunt ended fusiform nuclei admixed with dispersed cells or stripped nuclei. Some cells showed pleomorphism with occasional intranuclear vacuoles. Grossly the resected specimen was multiple nodular, brown, soft to firm, with the largest measuring 8.5x8x2.5 cm and the smallest 2.2x2.2x1 cm in size. On microscopic examination, sections showed fascicular pattern of atypical spindle cells having cigar shaped nuclei showing pleomorphism and eosinophilic fibrillary cytoplasm with 1-2 mitotic figures/10HPF. Immunohistochemistry with SMA showed strong diffuse cytoplasmic positivity and desmin showed mild focal cytoplasmic positivity in the tumor cells. A diagnosis consistent with primary multiple mesenteric leiomyosarcoma was given. Interventions: Wide surgical excision of the mass lesion was performed. The patient was subsequently administered 6 cycles of 5- Fluorouracil based chemotherapy. Outcomes: She is recovering well after 2 month of follow up period. Lessons: Our case will widen the vision of both physicians and pathologists to consider the possibility of primary mesenteric leiomyosarcoma in young females, presenting without any involvement of female genital tract, thus guide in the proper diagnosis and management of such lesions.

Cytological diagnosis of olfactory neuroblastoma at metastatic sites, with emphasis on role of insulinoma-associated protein 1 immunocytochemistry.

Olfactory neuroblastoma (ONB) is a rare neuroectodermal tumor with a propensity for lymph node and distant metastases in a proportion of cases, presenting opportunities for cytological diagnosis. Insulinoma-associated protein 1 (INSM1) is a recently identified marker of neuroendocrine differentiation with higher sensitivity and specificity than traditional neuroendocrine immunostains used in diagnosis of ONB. Archival aspirates diagnosed as metastatic ONB were retrieved and reviewed for described characteristics of ONB. Spare direct smears with sufficient cellular material from each case were selected, if available, and immunocytochemistry for INSM1 was performed on the destained alcohol-fixed smears. INSM1 was also performed on non-neuroendocrine malignant round cell tumors (MRCT). Seven fine needle aspirates (FNA) from five patients were identified, all of which showed a small round cell tumor with fine to coarse granular chromatin. Most cases had moderate to high cellularity, comprised of loosely cohesive clusters and dispersed cells. While two-cell pattern, nuclear streaking and moulding were frequent, background neuropil, fibrillary cytoplasm, and rosettes were uncommon. INSM1 immunostaining performed on spare direct smears showed strong positivity in 30%-100% of tumor cells (mean: 62%) in all aspirates tested (100%). In comparison with other immunostains, INSM1 showed more robust staining, and was easier to interpret. All non-neuroendocrine MRCTs were negative for INSM1. Metatstatic ONB can resemble other small round cell tumors, as all the diagnostic features of ONB may not be readily evident. INSM1 immunocytochemistry has high sensitivity and specificity and can reliably be used as a single marker to support the cytomorphology for a confirmatory diagnosis of ONB, even on direct smears if a cell block is not available.

Primary follicular dendritic cell sarcoma of the pleura: A clinicopathological and immunohistochemical study of two cases

Two cases of primary follicular dendritic cell sarcoma (FDCS) of the pleura are presented. The patients are a woman 76-years-old and a man 64-years-old who presented with nonspecific symptoms including chest pain, dyspnea, and cough. Clinical history did not disclose any pertinent history of previous malignancy. Diagnostic imaging showed the presence of a pleural-based mass in both patients and a thoracotomy with resection of the pleural mass was performed. Both tumors were described as solid, light tan, and with ill-defined borders. Histologically, both tumors showed similar histological features, namely the presence of a spindle cellular proliferation composed of elongated cells with fibrillary cytoplasm, oval nuclei, and conspicuous nucleoli. Mild to moderate cellular atypia was present, while mitotic figures ranged from 3 to 4 per 10 high power fields. Mature lymphocytes and plasma cells were also present dispersed throughout the tumor. Immunohistochemical stains in both cases show positive staining for CD21 and CD35 while focal staining was present for D2-40 and clusterin, while negative for other markers including keratin, desmin, S-100 protein, calretinin, and STAT-6. Clinical follow up shows that both patients have remained alive 12 and 14 months after initial diagnosis. The cases herein described represent an unusual occurrence of FDCS arising in the pleural surface and one that must be kept in mind when dealing with spindle cell tumors of the pleura.

In situ architecture of neuronal \u03b1-Synuclein inclusions

The molecular architecture of α-Synuclein (α-Syn) inclusions, pathognomonic of various neurodegenerative disorders, remains unclear. α-Syn inclusions were long thought to consist mainly of α-Syn fibrils, but recent reports pointed to intracellular membranes as the major inclusion component. Here, we use cryo-electron tomography (cryo-ET) to image neuronal α-Syn inclusions in situ at molecular resolution. We show that inclusions seeded by α-Syn aggregates produced recombinantly or purified from patient brain consist of α-Syn fibrils crisscrossing a variety of cellular organelles. Using gold-labeled seeds, we find that aggregate seeding is predominantly mediated by small α-Syn fibrils, from which cytoplasmic fibrils grow unidirectionally. Detailed analysis of membrane interactions revealed that α-Syn fibrils do not contact membranes directly, and that α-Syn does not drive membrane clustering. Altogether, we conclusively demonstrate that neuronal α-Syn inclusions consist of α-Syn fibrils intermixed with membranous organelles, and illuminate the mechanism of aggregate seeding and cellular interaction.

35. Follicular dendritic cell sarcoma of the nasopharynx

Background: Follicular dendritic cell sarcoma (FDCS) is a rare low-grade sarcoma, which presents as intranodal or, more commonly, extranodal disease at a wide variety of sites. To date, only eight cases of FDCS of the nasopharynx are reported.1,2 The morphological spectrum includes fascicular, whorled and sheet-like architecture with bland spindled to ovoid cells and possible nuclear pseudoinclusions. Occasionally, high-grade features including cytological atypia, numerous mitoses and necrosis are seen. Aims: To present the case of a 24-year-old female with a nasopharyngeal mass, subsequently diagnosed as FDCS. Methods: A biopsy was obtained which showed sheets of malignant cells, admixed with lymphocytes and occasional neutrophils. The cells had pale fibrillary cytoplasm, appearing syncytial in some areas. The nuclei were ovoid with fine chromatin, although with significant anisonucleosis, frequent large nuclear pseudoinclusions and occasional nucleoli. Numerous mitoses and areas of necrosis were present. Despite this unusual morphology, immunohistochemistry was positive for CD21, CD23 and CD35, indicative of FDCS. Results and conclusions: FDCS is an uncommon entity which, combined with variant morphology and an unusual site, can lead to a high risk of misdiagnosis; reported in four of six nasopharyngeal cases (67%).2 A high index of suspicion and broad immunohistochemical panel are required for diagnosis, particularly when high-grade features are present.

Tau protein phosphorylation at Thr175 initiates fibril formation via accessibility of the N-terminal phosphatase-activating domain.

One of the neuropathological hallmarks of the tauopathies is the formation of neuronal cytoplasmic inclusions and fibrils of microtubule-associated tau protein (tau). The phosphorylation of Thr175 of tau (pThr175 tau) appears to be sufficient for fibril formation in vitro and in vivo, but the mechanism by which this initiates fibril formation is unknown. Using transient transfections of tau mutants into HEK293T cells, we determined that the phosphorylation of Thr175 leads to exposure of the tau N-terminal phosphatase-activating domain (PAD). The exposed PAD is known to interact with protein phosphatase-1 (PP1) resulting in glycogen synthase kinase 3β (GSK3β) activation. In vivo, a single traumatic controlled cortical injury in rats also resulted in the phosphorylation of Thr175 and increased exposure of tau PAD followed by pathological tau fibril formation. Taken together, these data suggest that neurotoxicity may be precipitated by phosphorylation at Thr175 and subsequent tau PAD exposure, GSK3β activation and tau fibril formation. Cover Image for this issue: doi: 10.1111/jnc.14767.

An incidental finding of a paratesticular leiomyoma on varicocele repair

Introduction The paratesticular region is composed of spermatic cord, epididymis, vestigial remnants, and tunica vaginalis. Although paratesticular neoplasms are rare, they are clinically significant lesions that affect patients of all ages. Epididimal tumours, both primary and secondary, whether benign or malignant are extremely rare and the incidence is at most 0.03% of all male cancers. Benign tumours accounts for 75% of epididimal tumors cases. The most common benign epididymal tumour are adenomatoid tumors, followed by leiomyoma and papillary cystadenoma. Thus, we report a case of leiomyoma in a 51-year-old male who presented with a long standing history of gradual growing scrotal swelling. Case description A 51-year-old gentleman referred to the outpatient clinic with left scrotal pain and gradual swelling for more than 7 years. There were no associated obstructive lower urinary tracts symptoms, trauma, fever or constitutional symptoms. The patient had a background surgical history of left varicocele repair 7 years ago. He has an unremarkable past medical history. On examination, no masses were felt in the abdomen. There was an old scar at the left groin from the previous surgery and a hard non tender swelling was felt in the left scrotal sac inseparable from the left testes and epididymis, which was irreducible and not transluminant. Dilated and tortuous veins above the testicle ('bag of worms') were also identified which get decompressed on lying supine. Digital rectal examination was also normal. The patient's routine laboratory investigations were all within normal limits. Testicular tumor markers of Alpha fetoprotein and beta HCG were also requested and were normal. An ultrasound was done and showed a Grade III left varicocele with surrounding soft tissue density most likely hematoma and Grade I right varicocele. In view of the suspicious hard swelling in the left scrotal sac, he underwent left testicular exploration through a left inguinal approach and delivery of the left testis revealed an ovoid paratesticular mass attached to the tail of the left epididymis, measuring 2.5x2.5x2cm. Grossly it was firm and well circumscribed with a gray-white homogeneous surface. Complete enucleation of the left paratesticular mass was done and the specimen was sent to histopathology and microscopic-assisted bilateral varicocele repair was then carried out. Histopathology reported interlacing fascicles of spindle shaped cells with eosinophilic fibrillary cytoplasm, blunt ended nuclei elongated with fine chromatin, indistinct nucleolus and variable cytoplasmic vacuole at one end, minimal atypia, few mitotic figures and no coagulative tumor necrosis those featuring paratesticular leiomyoma. Results and conclusions Despite being rare, the diagnosis of leiomyoma of epididymis should be considered in the differential diagnosis of solid epididymal masses.

Cryo-electron tomography reveals novel features of a viral RNA replication compartment.

Positive-strand RNA viruses, the largest genetic class of viruses, include numerous important pathogens such as Zika virus. These viruses replicate their RNA genomes in novel, membrane-bounded mini-organelles, but the organization of viral proteins and RNAs in these compartments has been largely unknown. We used cryo-electron tomography to reveal many previously unrecognized features of Flock house nodavirus (FHV) RNA replication compartments. These spherular invaginations of outer mitochondrial membranes are packed with electron-dense RNA fibrils and their volumes are closely correlated with RNA replication template length. Each spherule's necked aperture is crowned by a striking cupped ring structure containing multifunctional FHV RNA replication protein A. Subtomogram averaging of these crowns revealed twelve-fold symmetry, concentric flanking protrusions, and a central electron density. Many crowns were associated with long cytoplasmic fibrils, likely to be exported progeny RNA. These results provide new mechanistic insights into positive-strand RNA virus replication compartment structure, assembly, function and control.

Recurrent SRF-RELA Fusions Define a Novel Subset of Cellular Myofibroma/Myopericytoma: A Potential Diagnostic Pitfall With Sarcomas With Myogenic Differentiation.

Cellular myofibroblastic tumors other than desmoid-type fibromatosis are often diagnostically challenging due to their relative rarity, lack of known genetic abnormalities, and expression of muscle markers which may be confused with sarcomas with myogenic differentiation. In this study we investigate the molecular alterations of a group of cellular myofibroblastic lesions with in the myofibroma and myopericytoma spectrum for better subclassification. Two index cases were studied by paired-end RNA sequencing for potential fusion gene discovery. One chest wall soft tissue tumor in a 3-month-old girl case showed a SRF-C3orf62 fusion, while the other, a forearm lesion in an 8-year-old girl, showed a SRF-RELA fusion. Further screening of 42 cellular examples of myofibroma/myopericytoma by fluorescence in situ hybridization identified additional 8 cases with recurrent SRF gene rearrangements, 6 of them showing identical SRF-RELA fusions. The cohort was composed of 7 females and 3 males, with a wide age range of 3 months to 63 years (mean=17). All tumors showed a densely packed growth of oval to spindle cells with fibrillary eosinophilic cytoplasm, arranged either in intersecting fascicles or with a distinct nested pattern around a rich vascular network. Despite the dense cellularity and variable mitotic activity none of the lesions displayed nuclear pleomorphism or necrosis. All tumors showed coexpression for SMA and desmin, in most cases with a strong and diffuse pattern of staining, while myogenin was consistently negative. No distant metastases were seen in the few cases with follow-up information. A control group of 34 well-characterized myofibroblastic and perivascular tumors, including 10 typical myofibromas and 3 myopericytomas, were also investigated for SRF gene abnormalities by fluorescence in situ hybridization and were negative. In summary, we report a subset of cellular variants of myofibroma and myopericytoma showing a smooth muscle-like immunophenotype and harboring recurrent SRF-RELA gene fusions, which mimic sarcomas with myogenic differentiation.

SLP-76 Adaptor Binding to SUMO-RANGAP1 of the Nuclear Pore Complex Regulates Multiple Aspects of T-cell Immunity

Abstract While immune cell adaptors regulate various proximal events in T cell signaling, the direct regulation of the nuclear pore complex (NPC) has not been reported. On the cytoplasmic side of the NPC, there are cytoplasmic filaments composed of two fundamental proteins RanGAP1 and RanBP2. We previously showed that the immune cell adaptor SLP-76 binds directly to SUMO-RanGAP1 of cytoplasmic fibrils of the NPC, and that this interaction is needed for optimal NFATc1 and NF-κB p65 nuclear entry in T cells (Liu et al., 2015 Mol Cell 59, 840–9). The use of a mutant form of SLP-76 that is unable to bind to RanGAP1 (i.e. K56E) reduced nuclear entry and T-cell cytokine production by >60%. It represents the second step in NFATc1 entry into the nucleus of T-cells following classic NFATc de-phosphorylation by calcineurin. We now show that K56E mutant reduced toll-like receptor induction of NF-κB nuclear entry (innate signaling) and that T-cells from K56E mutant mice show major defects in T-cell proliferation and immunity. Our findings further underscore the importance of this direct regulation of NPC function in T cell function.

P2.04-038 Primary Pulmonary Meningioma: Rare Tumor with Malignant Potential: Topic: Esophageal Cancer and Other Malignancies

Primary Pulmonary Meningioma (PPM) is a very rare tumor with approximately 40 cases described in previous medical literature. Although majority of the cases documented previously are benign, there were 3 cases that showed malignant characteristics. We report a case of PPM with atypical features. A 65-year-old lady, non-smoker, had an incidental finding of 1.9 × 1.6cm nodule in the right middle lobe on routine chest x-ray. The computed tomography (CT) of the thorax demonstrated a well-defined, homogeneous soft tissue nodule measuring 1.5 × 1.5 cm in the lateral segment of the right middle lobe. CT-guided biopsy did not show features of malignancy. Hence, the patient was managed conservatively with surveillance CT scans. Four years later, repeat CT thorax revealed enlargement of the tumor size to 3.1 × 2.2 cm, with increased lobulations. The patient underwent completely portal robotic middle lobectomy and mediastinal lymph node dissection. The patient made an uneventful recovery and was discharged on post-operative day 3. Histological examination revealed a 3.8 cm solid, circumscribed, whitish, homogeneous nodule that abuts the pleural surface. Microscopically, the tumor comprised of bland spindle cells arranged in fascicles and occasional whorls. The cells had round to ovoid nuclei and moderate amounts of eosinophilic fibrillary cytoplasm. Up to 7 mitotic figures per 10 high power fields were identified. Stromal hyalinization, ectatic blood vessels and focal necrosis were seen in some area. The tumor cells were diffusely positive for vimentin and S-100, focally positive for cytokeratin AE1/3, synaptophysin and EMA, and negative for chromogranin. Overall, histology of the specimen demonstrated characteristic patterns of meningiomas with atypical features. The lymph nodes sampled were negative for malignancy. There were no intra-cranial or spinal lesions. There was no tumor recurrence at the 1-yr follow-up. PPM is a rare tumor which requires timely surgical resection for diagnosis and treatment. Untreated benign behaving lesions have the potential to become aggressive and demonstrate atypical features.

Thymic Hassall's corpuscles in Nandanam chicken - light and electronmicroscopic perspective (Gallus domesticus).

The present study was aimed to study the light and electron microscopic studies of thymic Hassall’s corpuscles was done in various age groups of Nandanam Chicken ranging from day-old to forty weeks. Hassall’s corpuscles are special, unique structures present in thymic medulla and also in the cortex of all the age groups of Nandanam chicken (from hatch to forty weeks) in the present study. Size of the Hassall’s corpuscles in the medulla is larger than the ones present in the cortical region of thymus. The Hassall’s corpuscles are made up of structureless eosinophilic mass surrounded by concentrically arranged reticuloepithelial cells. Under electron microscope, the Hassall’s corpuscles were composed of reticuloepithelial cells interconnected by many desmosomes. The epithelial cells had abundance of cytoplasmic fibrils and desmosomes with few mitochondria and ribosomes. The nucleus was oval or round which was slightly indented. The centre of the Hassall’s corpuscles was appeared either solid or cystic. The cystic corpuscles had cell debris within the cyst lumen.

The Immune Adaptor SLP-76 Binds to SUMO-RANGAP1 at Nuclear Pore Complex Filaments to Regulate Nuclear Import of Transcription Factors in T Cells

SummaryWhile immune cell adaptors regulate proximal T cell signaling, direct regulation of the nuclear pore complex (NPC) has not been reported. NPC has cytoplasmic filaments composed of RanGAP1 and RanBP2 with the potential to interact with cytoplasmic mediators. Here, we show that the immune cell adaptor SLP-76 binds directly to SUMO-RanGAP1 of cytoplasmic fibrils of the NPC, and that this interaction is needed for optimal NFATc1 and NF-κB p65 nuclear entry in T cells. Transmission electron microscopy showed anti-SLP-76 cytoplasmic labeling of the majority of NPCs in anti-CD3 activated T cells. Further, SUMO-RanGAP1 bound to the N-terminal lysine 56 of SLP-76 where the interaction was needed for optimal RanGAP1-NPC localization and GAP exchange activity. While the SLP-76-RanGAP1 (K56E) mutant had no effect on proximal signaling, it impaired NF-ATc1 and p65/RelA nuclear entry and in vivo responses to OVA peptide. Overall, we have identified SLP-76 as a direct regulator of nuclear pore function in T cells.

Demonstration of primary cilia and acetylated α-tubulin in fish endothelial, epithelial and fibroblast cell lines.

Primary cilia (PC) were demonstrated for the first time in fish endothelial, epithelial and fibroblast cell lines through immunofluorescence staining with the monoclonal antibody, 6-11B-1, against acetylated α-tubulin. The study was carried out with eight recently developed cell lines from the walleye, Sander vitreus (Mitchill). These were three fibroblast-like cell lines, WE-cfin11f, WE-skin11f and WE-liver3 from, respectively, the caudal fin, skin and liver, and three epithelial-like cell lines, WE-cfin11e, WE-spleen6 and WErpe from, respectively, the caudal fin, spleen and retina. Also, endothelial-like WEBA from the bulbus arteriosus and glial-like WE-brain5 from the brain were used. Immunocytochemistry revealed strong staining for acetylated α-tubulin in mitotic spindles and midbodies for all cell lines, and in PC for all cell lines except WE-skin11f. Staining of cytoplasmic microtubules (fibrils) was absent in three cell lines, including WEBA, but present in the others, especially WE-skin11f, which might have obscured PC detection in these cells. Tubacin, an inhibitor of histone deacetylase 6, induced cytoplasmic fibrils in WEBA and the intensity of their staining in WE-cfin11f. These results suggest that the cell lines might differ in their deacetylase activities, making them useful for studying this tubulin modification in teleosts, as well as for studying PC.

Genetic testing of leiomyoma tissue in women younger than 30 years old might provide an effective screening approach for the hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC).

We have studied the viability of targeted molecular screening for the identification of female patients with hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. Affected patients harbor a germ-line heterozygous mutation of the fumarate hydratase (FH) gene. Clinically, some patients present with aggressive renal cell carcinoma. Concerning women, in almost all cases, this is preceded by symptomatic uterine leiomyoma. We aimed to identify women operated on for symptomatic leiomyoma by the age of 30. Archived paraffin-embedded leiomyoma tissue was tested for the FH gene mutation in 14 cases. Two patients with multiple leiomyomas and with the confirmed germ-line mutations c.1433_1434dupAAA, p.(Lys477dup) and c.953A>T, p.(His318Leu) were identified and enrolled in a surveillance program. Statistically significant correlation between the presence of multiple uterine leiomyomas (more than seven in our experience) and the FH gene mutation was found. The immunohistochemical expression pattern, of simultaneous FH absence and S-(2-succino)cysteine (2SC) positivity, correlated with the results of the molecular genetic study in only one case. The histomorphologically simultaneous detection of enlarged nucleoli with a clear halo of leiomyocyte nuclei, their fibrillary cytoplasm, the presence of eosinophilic globules, and staghorn vessels proved to be only a partially sensitive indicator of HLRCC-associated leiomyoma and fully correlated with immunohistochemistry and molecular genetic study only in one case. Molecular genetic testing is presently the only reliable diagnostic tool able to identify HLRCC patients. The sensitivity and specificity of the presence of multiple leiomyomas in women with the FH gene mutation who are younger than 30 years old should be confirmed in larger scale studies. The applied targeted molecular screening protocol proved to be effective, resulting in identification of two positive patients out of fourteen tested individuals.

Diffuse pulmonary meningotheliomatosis: A diagnostically challenging entity on fine‐needle aspiration cytology

Diffuse pulmonary meningotheliomatosis (DPM) is an exceedingly rare entity consisting of multiple minute pulmonary meningothelial-like nodules profusely involving the lungs. To the best of our knowledge, we present the first cytologic description of this uncommon lesion from a 57-year-old nonsmoking woman. Computerized tomographic-guided fine-needle aspiration cytology from a left upper lobe nodule showed whorled/nested clusters of elongated cells with oval nuclei, clear pseudonuclear inclusions, nuclear grooves/indentations, smooth nuclear contours, fine granular chromatin, inconspicuous nucleoli, and abundant fibrillary cytoplasm with indistinct cell borders. The subsequent pulmonary wedge resections confirmed the diagnosis of DPM. As this condition is exceptionally rare, familiarity with these cytologic features is of the essence to accurately establish this challenging diagnosis.

Rapid growth of massive retinal gliosis in an infant

Introduction: Massive retinal gliosis (MrG) is a rare, benign intraocular tumor that results from the proliferation of well-differentiated glial cells. MrGs develop because of a variety of causes. case report: We encountered a case of a 2-year-old male infant with loss of vision in the right eye. Enucleation was carried out due to an absolute glaucoma. Histologically, the vitreous body had been totally replaced by massively proliferated spindle cells, which had delicate fibrillary cytoplasm without nuclear atypia. Immunohistochemically, the cells were strongly positive for glial fibrillary acidic protein. these findings led to a diagnosis of massive gliosis. conclusion: Massive retinal gliosis (MrG) is a rare, benign intraocular tumor that results from the proliferation of well-differentiated glial cells. to our knowledge, this may be the first report of such an occurrence in a 2-yearold infant. It is important for ophthalmologists to be suspicious of a mass resistant to chemotherapy that resembles a rb in children.