Applied Compressive Strain Governs Hyaline-like Cartilage versus Fibrocartilage-like ECM Produced within Hydrogel Constructs.

The goal of cartilage tissue engineering (CTE) is to regenerate new hyaline cartilage in joints and treat osteoarthritis (OA) using cell-impregnated hydrogel constructs. However, the production of an extracellular matrix (ECM) made of fibrocartilage is a potential outcome within hydrogel constructs when in vivo. Unfortunately, this fibrocartilage ECM has inferior biological and mechanical properties when compared to native hyaline cartilage. It was hypothesized that compressive forces stimulate fibrocartilage development by increasing production of collagen type 1 (Col1), an ECM protein found in fibrocartilage. To test the hypothesis, 3-dimensional (3D)-bioprinted hydrogel constructs were fabricated from alginate hydrogel impregnated with ATDC5 cells (a chondrogenic cell line). A bioreactor was used to simulate different in vivo joint movements by varying the magnitude of compressive strains and compare them with a control group that was not loaded. Chondrogenic differentiation of the cells in loaded and unloaded conditions was confirmed by deposition of cartilage specific molecules including glycosaminoglycans (GAGs) and collagen type 2 (Col2). By performing biochemical assays, the production of GAGs and total collagen was also confirmed, and their contents were quantitated in unloaded and loaded conditions. Furthermore, Col1 vs. Col2 depositions were assessed at different compressive strains, and hyaline-like cartilage vs. fibrocartilage-like ECM production was analyzed to investigate how applied compressive strain affects the type of cartilage formed. These assessments showed that fibrocartilage-like ECM production tended to reduce with increasing compressive strain, though its production peaked at a higher compressive strain. According to these results, the magnitude of applied compressive strain governs the production of hyaline-like cartilage vs. fibrocartilage-like ECM and a high compressive strain stimulates fibrocartilage-like ECM formation rather than hyaline cartilage, which needs to be addressed by CTE approaches.

Small Cell Type Undifferentiated Carcinoma of Gall Bladder with Pas Positive Hyaline Globule Masquerading as Liver Mass: A Case Report and Literature Review.

An undifferentiated carcinoma (UC) of the gall bladder behaves aggressively and has a grave prognosis. Small cell type undifferentiated carcinoma of the gall bladder is a rare variant. This paper reports a case of UC of gall bladder with PAS-positive diastase- resistant eosinophilic hyaline globules present as liver mass (on imaging) in a male patient. The microscopic findings of the liver and gall bladder after a right tri-segmentectomy showed an un-differentiated malignant neoplasm composed of cells with round to oval nuclei, prominent nucleoli, and scanty neoplasm. No definite cell pattern was identified with these neoplastic cells. A section from the gall bladder revealed a tumor arising from the lining epithelium and infiltrating through the muscularis. This tumor was infiltrating the adherent liver tissue directly and forming a mass of undifferentiated malignant cells. The focal area within the tumor mass showed the presence of PAS-positive, diastase-resistant, eosinophilic hyaline globules within the neoplastic cells. The immunohistochemistry test was diffusely positive for perinuclear anti-neutrophil cytoplasmic antibodies and negative for chromogranin, vimentin, Desmin, alpha-fetoprotein, leukocyte common antigen, CD34, and bcl2. When the clinical and radiological data are inconclusive, careful analysis of the histological and immunophenotypic features is needed to make the final diagnosis of UC of the gall bladder. The biological behavior and prognosis of this tumor remain unclear because of its rarity. Further studies will be needed to understand the characteristics of this deadly tumor and to establish an effective therapy for it.

Hyaline Protoplasmic Astrocytopathy in the Setting of Epilepsy.

OBJECTIVES: Cerebral hyaline protoplasmic astrocytopathy (HPA) is a clinicopathologic entity characterized by eosinophilic cytoplasmic inclusions within astrocytes. It has been observed in a subset of patients with early-onset epilepsy, brain malformations, and developmental delay. The exact association of this entity with epilepsy is still unknown. This report, with its review of the literature, aims to summarize HPA features to raise awareness regarding this entity. METHODS: We report on 2 HPA cases and critically review the literature. RESULTS: Approximately 42 cases of HPA have been reported, including the 2 cases presented here, consisting of 23 female and 19 male patients. Patient age ranged from 3 to 39 years. All patients had early-onset seizures (3-20 months of age), ranging from partial to generalized, that were refractory despite treatment with antiepileptic drugs. Postoperative follow-up intervals ranged from 2 to 93 months, and the clinical outcome was graded according to the Engel classification, showing variable results. CONCLUSIONS: Clinicians should consider HPA in differential diagnosis in patients with intractable seizures, especially when they are associated with developmental delay and brain malformations. Increasing awareness of this entity among pathologists may promote better understanding of this condition as well as better diagnosis and treatment for these patients.

Superlarge living hyaline cartilage graft contributed by the scale-changed porous 3D culture system for joint defect repair.

It is known that an excellent hyaline cartilage phenotype, an internal microstructure with safe crosslinking and available size flexibility are the key factors of cartilage grafts that allow for clinical application. Living hyaline cartilage grafts (LhCGs) constructed by phase-transfer hydrogel (PTCC) systems were reported to have a hyaline phenotype and bionic microstructure. By employing chondrocytes to secrete matrix in the hydrogel and then removing the material to obtain material-free tissuein vitro, LhCG technology exhibited superior performance in cartilage repair. However, PTCC systems could only produce small-sized LhCGs because of medium delivery limitations, which hinders the clinical application of LhCGs. In this study, we prepared three different noncrosslinked gelatin microspheres with diameters from 200 µm to 500 µm, which replaced the original pore-forming agent. The new PTCC system with the mixed and gradient porous structure was used for the preparation of superlarge LhCGs with a continuous structure and hyaline phenotype. Compared to the original technique, the porous gradient structure promoted nutrient delivery and cartilage matrix secretion. The small size of the microporous structure promoted the rapid formation of matrix junctions. The experimental group with a mixed gradient increased cartilage matrix secretion significantly by more than 50% compared to the that of the control. The LhCG final area reached 7 cm2without obvious matrix stratification in the mixed gradient group. The design of the scale-changed porous PTCC system will make LhCGs more promising for clinical application.

A novel diagnostic tool for hyaline vascular Castleman disease versus lymphoma based on contrast-enhanced computed tomography in neck mass.

BACKGROUND: Castleman disease and lymphoma each have a distinct treatment plan; however, they share the same features on contrast-enhanced computed tomography. METHODS: To assess the quantitative outcomes of Castleman disease versus lymphoma using contrast-enhanced computed tomography based on Hounsfield units (HU). We retrospectively reviewed eight patients with unicentric Castleman disease and 30 patients with lymphoma based on pathological diagnosis at China Medical University Hospital between 2015 and 2020. Preoperative computed tomography with contrast scans was reviewed, and the HU of each tumor were measured. RESULTS: This study included eight patients with unicentric Castleman disease (four men and four women; mean age, 33 years) and 25 patients with lymphoma (11 men and 14 women; mean age, 53 years). There was no significant difference in heterogeneity between the two diseases (0.161 ± 0.052 vs 0.239 ± 0.063, p = 0.22); however, enhancement in Castleman disease was higher than that in lymphoma (126.40 ± 31.90 vs 74.19 ± 7.11, p < 0.001), providing a very good diagnostic tool (cutoff point at 88.5-91.3, sensitivity 0.86/specificity 0.88). Furthermore, we found a highly linear relationship in Castleman disease, which was not noted in lymphoma. CONCLUSION: The value of HU provides a good diagnostic tool for the differential diagnosis of Castleman disease versus lymphoma in the neck lymph nodes. Considering the linear relationship in Castleman disease, an increasingly accurate differential diagnosis can be made.

Generation of hyaline-like cartilage tissue from human mesenchymal stromal cells within the self-generated extracellular matrix.

Chondrocytic hypertrophy, a phenotype not observed in healthy hyaline cartilage, is often concomitant with the chondrogenesis of human mesenchymal stromal cells (hMSCs). This undesired feature represents one of the major obstacles in applying hMSCs for hyaline cartilage repair. Previously, we developed a method to induce hMSC chondrogenesis within self-generated extracellular matrix (mECM), which formed a cartilage tissue with a lower hypertrophy level than conventional hMSC pellets. In this study, we aimed to test the utility of hypoxia and insulin-like growth factor-1 (IGF1) on further reducing hypertrophy. MSC-mECM constructs were first subjected to chondrogenic culture in normoxic or hypoxic (5%) conditions. The results indicated that hMSC-derived cartilage formed in hypoxic culture displayed a significantly reduced hypertrophy level than normoxic culture. However, hMSC chondrogenesis was also suppressed under hypoxic culture, partially due to the reduced activity of the IGF1 pathway. IGF1 was then supplemented in the chondrogenic medium, which promoted remarkable hMSC chondrogenesis under hypoxic culture. Interestingly, the IGF1-enhanced hMSC chondrogenesis, under hypoxic culture, was not at the expense of promoting significantly increased hypertrophy. Lastly, the cartilage tissues created by hMSCs with different conditions were implanted into osteochondral defect in rats. The results indicated that the tissue formed under hypoxic condition and induced with IGF1-supplemented chondrogenic medium displayed the best reparative results with minimal hypertrophy level. Our results demonstrate a new method to generate hyaline cartilage-like tissue from hMSCs without using exogenous scaffolds, which further pave the road for the clinical application of hMSC-based cartilage tissue engineering. STATEMENT OF SIGNIFICANCE: In this study, hyaline cartilage-like tissues were generated from human mesenchymal stromal cells (hMSCs), which displayed robust capacity in repairing the osteochondral defect in rats. In particular, the extracellular matrix created by hMSCs was used, so no exogenous scaffold was needed. Through a series of optimization, we defined that hypoxic culture and supplementation of insulin-like growth factor-1 (IGF-1) in chondrogenic medium resulted in robust cartilage formation with minimal hypertrophy. We also demonstrated that hypoxic culture suppressed chondrogenesis and hypertrophy through modulating the Wnt/ß-catenin and IGF1 pathways, respectively. Our results demonstrate a new method to generate hyaline cartilage-like tissue from hMSCs without using exogenous scaffolds, which will further pave the road for the clinical application of hMSCs-based cartilage tissue engineering.

Novel ALK-EML4 fusion with prominent mucous and hyaline stroma: Expanding the molecular genetic spectrum of S100 and CD34 positive spindle cell tumor.

We report a case of a 49-year-old male patient suffering from an intraspinal tumor in the lumbar vertebra. The neoplasm was composed of mono-morphic spindle cells, arrayed in a patternless pattern in a background of prominent myxoid hyaline stroma with perivascular collagen rings in hyper-cellular regions. Instead, aggregated collagen fibers arranged into nodules and apparent calcium deposition were found in hypo-cellular regions. The tumor cells showed immunopositivity with S100 and CD34, whereas lacked SOX10 expression, which were reminiscent of a group of S100 and CD34 co-expression soft tissue spindle cell lesions having recurrent fusions including RAF1, BRAF, NTRK1/2/3, and RET genes. Interestingly, a novel anaplastic lymphoma kinase (ALK)- echinoderm microtubule-associated protein-like 4 (EML4) gene fusion was revealed. To our best knowledge, it was the first time to identify such gene fusion in the Orientals among this mentioned group, and it expands the molecular genetic spectrum of this specific group. The clinical relevance of this novel fusion requires further investigations.

[Hyaline juvenile fibromatosis: clinic, diagnostics, treatment]. / Gialinovyi yuvenil'nyi fibromatoz: klinika, diagnostika, lechenie.

Hyaline juvenile fibromatosis is a rare genetic disease, which is associated with ANTXR2 gene defect. Almost all organs and systems of the body are affected in this pathology. There are clinical symptoms: joint contracture, hyperpigmentation, skin damage like nodules, which can have different sizes, locations and forms, throughout the body, fibromatosis of the gums, internal organs damages (splenomegaly, hepatomegaly, anomalies of the kidneys and other organs), osteoporosis, increased susceptibility to infectious diseases, mental underdevelopment. In this article we describe clinical case of 6-old patient witht hyaline juvenile fibromatosis. The diagnosis was made on the basis of the clinical picture, additional research methods and the results of molecular genetic testing. The patient underwent a number of surgical interventions, histological examination of the surgical material and symptomatic therapy.

The value of 'raspberry bodies' in intraoperative cytologic evaluation of adnexal masses for the diagnosis of clear cell carcinoma of the ovary: A cytological-pathological correlation.

We report a case of a 48-year-old female who presented to the emergency department with pelvic/abdominal pain and a recent history of irregular periods. Pelvic ultrasound and computed tomography (CT) scan of the abdomen/pelvis revealed a 7.3 cm adnexal mass with suspicious features. During the intraoperative evaluation, a frozen section slide and a cytological smear were prepared. The cytological preparation was moderately cellular, showing cohesive groups of atypical cells with anisonucleosis, high nuclear to cytoplasmic ratio, and oval nuclei with prominent nucleoli. The tumor cells surrounded extracellular, magenta hyaline globules, forming raspberry bodies. Raspberry bodies are comprised of basement membrane deposits and are a unique finding in ovarian clear cell carcinoma. Raspberry bodies were also found in the frozen section slide, but, in comparison to the cytological preparation, were rare, difficult to identify, and resembled necrotic debris. The intraoperative diagnosis of a clear cell carcinoma is important because the surgical management will be more aggressive, as optimal tumor debulking is shown to have better overall survival. In this manuscript, we detail the intraoperative evaluation of an ovarian mass, the utility of cytological preparation and importance of identifying raspberry bodies in the evaluation of ovarian masses, and surgical management of clear cell carcinoma.

Profile of vascular markers and CT enhancement of hyaline vascular type Castleman's disease.

Blood vessels in lymph nodes (LNs) are unique in comprising both capillaries and high endothelial venules (HEVs). Hyaline vascular type Castleman's disease accompanies robust angiogenesis, but it is unclear how the capillaries and HEVs respond. We retrospectively examined surgical specimens of hyaline vascular type unicentric Castleman's disease patients (n = 24) and control LNs (n = 9). We performed immunohistochemistry of CD 31 for capillaries and MECA-79 for HEVs and calculated their microvascular density. We measured CT enhancement as the ratio of Hounsfield Units (HUs) of the target lesion against muscle compared with microvascular density. The microvascular density of Castleman's disease specimen were (CD 31+) 169.7 ± 77.6, (MECA-79+) 203.5 ± 96.7, and the microvascular density of control LNs were (CD 31+) 80.7 ± 20.1, (MECA-79+) 67.4 ± 23.7, respectively. The microvascular density of both CD 31+ (P < 0.001) and MECA-79+ (P < 0.001) was higher in Castleman's disease. A positive correlation existed between CT HU ratio and microvascular density for both markers (CD 31: r = 0.517, P = 0.002; MECA-79: r = 0.521, P = 0.002). Intra-nodal angiogenesis of Castleman's disease involves robust proliferation of not only CD 31+ capillaries, but also MECA-79+ HVEs, which each correlated with degree of CT enhancement.

Visceral fat inflammation and fat embolism are associated with lung's lipidic hyaline membranes in subjects with COVID-19.

BACKGROUND: Preliminary data suggested that fat embolism could explain the importance of visceral obesity as a critical determinant of coronavirus disease-2019 (COVID-19). METHODS: We performed a comprehensive histomorphologic analysis of autoptic visceral adipose tissue (VAT), lungs and livers of 19 subjects with COVID-19 (COVID-19+), and 23 people without COVID-19 (controls). Human adipocytes (hMADS) infected with SARS-CoV-2 were also studied. RESULTS: Although there were no between-group differences in body-mass-index and adipocytes size, a higher prevalence of CD68+ macrophages among COVID-19+ VAT was detected (p = 0.005) and accompanied by crown-like structures presence, signs of adipocytes stress and death. Consistently, human adipocytes were successfully infected by SARS-CoV-2 in vitro and displayed lower cell viability. Being VAT inflammation associated with lipids spill-over from dead adipocytes, we studied lipids distribution by ORO. Lipids were observed within lungs and livers interstitial spaces, macrophages, endothelial cells, and vessels lumen, features suggestive of fat embolism syndrome, more prevalent among COVID-19+ (p < 0.001). Notably, signs of fat embolism were more prevalent among people with obesity (p = 0.03) independently of COVID-19 diagnosis, suggesting that such condition may be an obesity complication exacerbated by SARS-CoV-2 infection. Importantly, all infected subjects' lungs presented lipids-rich (ORO+) hyaline membranes, formations associated with COVID-19-related pneumonia, present only in one control patient with non-COVID-19-related pneumonia. Importantly, transition aspects between embolic fat and hyaline membranes were also observed. CONCLUSIONS: This study confirms the lung fat embolism in COVID-19+ patients and describes for the first time novel COVID-19-related features possibly underlying the unfavorable prognosis in people with COVID-19 and obesity.

Choroid Plexus Carcinoma with Hyaline Globules: An Uncommon Histological Finding.

Background: Choroid plexus carcinoma (CPC) is a predominately pediatric CNS tumor with a variety of histologic features, with hyaline globules only reported once previously. Case report: A two-year-old male child presented with headaches, vomiting, and lower limb weakness. Radiological examination revealed a right temporoparietal intra-axial tumor. On histology, it showed features of CPC containing multiple eosinophilic intracytoplasmic and extracellular hyaline globular structures, which were PAS-positive, diastase resistant, and immunoreactive for alpha-fetoprotein (AFP). Conclusion: CPC can occasionally show AFP immune-positive hyaline globules.

Atypical Presentation of Juvenile Hyaline Fibromatosis of Hands.

Juvenile hyaline fibromatosis is a rare disorder characterized by an extracellular accumulation of hyaline deposit. In the extremities, lesions may remain quiescent or gradually increase in size, eventually resulting in skin ulceration. There is no curative treatment. Surgery may allow some recovery of function, but recurrence is possible. We report a case of juvenile hyaline fibromatosis in both hands of a 25-year-old man who required multiple surgical procedures to address problems with function, pain, and appearance.