Somatic GJA4 mutation in intracranial extra-axial cavernous hemangiomas.

OBJECTIVE: Extra-axial cavernous hemangiomas (ECHs) are sporadic and rare intracranial occupational lesions that usually occur within the cavernous sinus. The aetiology of ECHs remains unknown. METHODS: Whole-exome sequencing was performed on ECH lesions from 12 patients (discovery cohort) and droplet digital polymerase-chain-reaction (ddPCR) was used to confirm the identified mutation in 46 additional cases (validation cohort). Laser capture microdissection (LCM) was carried out to capture and characterise subgroups of tissue cells. Mechanistic and functional investigations were carried out in human umbilical vein endothelial cells and a newly established mouse model. RESULTS: We detected somatic GJA4 mutation (c.121G>T, p.G41C) in 5/12 patients with ECH in the discovery cohort and confirmed the finding in the validation cohort (16/46). LCM followed by ddPCR revealed that the mutation was enriched in lesional endothelium. In vitro experiments in endothelial cells demonstrated that the GJA4 mutation activated SGK-1 signalling that in turn upregulated key genes involved in cell hyperproliferation and the loss of arterial specification. Compared with wild-type littermates, mice overexpressing the GJA4 mutation developed ECH-like pathological morphological characteristics (dilated venous lumen and elevated vascular density) in the retinal superficial vascular plexus at the postnatal 3 weeks, which were reversed by an SGK1 inhibitor, EMD638683. CONCLUSIONS: We identified a somatic GJA4 mutation that presents in over one-third of ECH lesions and proposed that ECHs are vascular malformations due to GJA4-induced activation of the SGK1 signalling pathway in brain endothelial cells.

The FcεRI signaling pathway is involved in the pathogenesis of lacrimal gland benign lymphoepithelial lesions as shown by transcriptomic analysis.

This study aimed to analyze the role of the FcepsilonRI (FcεRI) signaling pathway in the pathogenesis of benign lymphoepithelial lesion of lacrimal gland (LGBLEL). Transcriptomic analysis was performed on LGBLEL and orbital cavernous hemangioma (CH) patients diagnosed via histopathology in Beijing Tongren Hospital, Capital Medical University, between July 2010 and October 2013. Four LGBLEL and three orbital CH patients, diagnosed between October 2018 and August 2019, were randomly selected as experimental and control groups, respectively. RT-PCR, immunohistochemical staining, and western blotting were used to verify genes and proteins related to the FcεRI signaling pathway. Transcriptomic analysis showed that the FcεRI signaling pathway was upregulated in the LGBLEL compared with the CH group. The mRNA expression levels of important genes including SYK, p38, JNK, PI3K, and ERK were significantly increased in the LGBLEL group (P = 0.0066, P = 0.0002, P = 0.0003, P < 0.0001, P < 0.0001, respectively). Immunohistochemical staining results showed that SYK, p38, and ERK were positively expressed in LGBLEL, while JNK and PI3K were not. The protein contents of P-SYK, P-p38, P-JNK, P-PI3K, and P-ERK were significantly higher in the LGBLEL than in the CH group (P = 0.0169, P = 0.0074, P = 0.0046, P = 0.0157, P = 0.0156, respectively). The FcεRI signaling pathway participates in the pathogenesis of LGBLEL.

C-KIT Expression in Orbital Cavernous Venous Hemangiomas.

Orbital (slow flow) cavernous venous hemangiomas (OCVH) are the most common benign orbital tumors in adults. The c-KIT is a tyrosine kinase receptor, which is expressed on several types of cells, is thought to play a key role in tumor pathogenesis. The purpose of this study was to evaluate the presence of the receptor c-KIT in OCVH. Our retrospective study examined 16 orbital cavernous venous hemangiomas from 16 cases operated on between 2006-2016 at Emek Medical Center. The mean tumor size was 18.4 mm. Symptoms appeared between 6 months and 22 years before operation. All specimens were analyzed for the c-KIT receptor through immunohistochemistry. The c-KIT was expressed by the endothelium in all 16 preparates. Staining was strong in two cases, moderate in six, and weak in eight cases, with no statistically significant correlation between staining and tumor size (p = 0.69) or the symptom duration (p = 0.15). We conclude that c-KIT may play an important role in the pathogenesis of OCVH. This pilot study is significant in that tumor-targeted therapy such as Imatinib Mesylate and Sunitinib may have a role in treating surgically complicated cases located in the orbital apex. A large multicenter collaborative study is necessary to examine the role of c-KIT in OCVH.

COMPARATIVE STUDY OF GROWTH INHIBITORY PROTEIN COMPLEX DERIVED FROM DIFFERENT FORMS OF CHILDREN HEMANGIOMA.

The comparative analysis of the thermostable protein complexes obtained from the capillary and the cavernous hemangioma was carried out. It is shown that the active component (with low molecular weight 12-14 kD) is in minor content in the complexes obtained from capillary, as well as from the cavernous hemangioma. The effect of protein complexes from cavernous hemangiomas on proliferation of the brain and pancreatic cells in growing rats was studied. It was established that the thermostable protein complex from cavernous hemangiomas does not have the ability to inhibit the proliferation of heterotypic cells due to the minor content of the active ingredient in protein complexes.

Classification and Tie2 mutations in spinal and soft tissue vascular anomalies.

Vascular anomalies included hemangiomas and vascular malformations (VMs). VMs are mediated by mutations in the endothelial cell-specific receptor tyrosine kinase Tie2 (TEK),which is essential for angiogenesis and vascular stabilization. We identified five types of Tie2 mutations in 80 patients with soft tissue or spinal VMs by PCR including the previously detected missense mutations 2690A>G (Y897C), 2740C>T (L914F), 2743C>T (R915C), and two nonsense mutations 2763G>A, 2688C>T, we identified Tie2 mutation in primary spinal VMs for the first time. Tie2 mutations were found to be absent in 33 patients with hemangiomas and DNA samples of VMs. In addition, we showed that Tie2 mRNA expression in spinal VMs was similar to soft tissue VMs, but obviously lower than infant hemangiomas (P<0.01). This study provides new insights into spinal VMs, the association of Tie2 and vascular anomalies needs to be further discussed.

CD105 expression in oral capillary hemangiomas and cavernous hemangiomas.

Capillary hemangioma (capillary lobular hemangioma) and cavernous hemangioma (venous malformation) are relatively common oral tumors/malformations and are characterized by increased numbers of normal and abnormal blood vessels. However, the causes of these lesions are not well understood. CD105 (endoglin) is predominantly expressed in proliferating blood endothelial cells (ECs). We analyzed expressions of CD105, CD34, von Willebrand factor, Ki-67, cyclooxygenase-2 (COX-2), and vascular endothelial growth factor (VEGF)-A in 31 capillary hemangiomas and 34 cavernous hemangiomas. Staining scores were calculated as the product of the proportion score and intensity score. Morphologically normal oral mucosa specimens (n = 10) were simultaneously evaluated as normal controls. As compared with cavernous hemangiomas and normal controls, capillary hemangiomas had higher staining scores for CD105, VEGF-A, and COX-2. The Ki-67 labeling index was significantly higher in capillary hemangiomas than in cavernous hemangiomas and normal controls (P < 0.01). These findings suggest that the biological characteristics of capillary and cavernous hemangiomas are quite different. The ECs of capillary hemangiomas actively proliferated and were generally regulated by VEGF-A. In contrast, the ECs of cavernous hemangiomas lacked proliferative activity. These results suggest that angiogenesis and vasodilatation of pre-existing blood vessels are important in the development of capillary hemangioma and cavernous hemangioma, respectively.

A case of middle mediastinal cavernous hemangioma.

A 51-year-old female was referred to our clinic for investigation of abnormal chest X-ray findings during a routine health examination. Chest computed tomography showed a middle mediastinal tumor, and she was admitted to hospital for surgical treatment. The tumor was removed using thoracoscopic surgery, without significant blood loss. Pathological examination showed that the tumor was composed of blood vessels with relatively thick vascular walls containing smooth muscle. Immunohistochemical staining was positive for CD34 and Factor VIII, and negative for D2-40. Based on these findings, the tumor was diagnosed as a cavernous hemangioma. We herein present this very rare case of middle mediastinal cavernous hemangioma.

Cavernous venous malformations of the orbit (so-called cavernous haemangioma): a comprehensive evaluation of their clinical, imaging and histologic nature.

PURPOSE: The purpose of this investigation is to describe the clinical, imaging, histologic and flow dynamic characteristics of orbital cavernous haemangioma. METHODS: In this clinicopathologic series, clinical features were obtained from patient records. All imaging studies were reviewed. All specimens were reviewed with haematoxylin and eosin, and 10 were subject to a staining protocol including: Movat Pantachrome, periodic acid Schiff, D2-40, CD31, GLUT-1, Ki-67, vascular endothelial growth factor receptor 1 (VEGF-r1) (flt-1), VEGF-r2 (Flk-1), VEGF, anti-smooth muscle actin (SMA), CD20, CD4, CD8 and CD68. Imaging and pathology were reviewed in a systematic fashion. RESULTS: Clinically, lesions were more common in middle-aged females presenting with axial proptosis and pain. One-third demonstrated signs of optic nerve dysfunction. Dynamic imaging revealed focal early and diffuse late enhancement. Lesions demonstrated slow growth at 0.2 cm3/year. Histologically, all lesions demonstrated large vascular channels with mature-appearing endothelium and abundant stroma. Three salient features were noted and characterised: thrombosis, nests of perivascular hypercellularity and expanded stromal elements. Acute thrombosis was a feature of each specimen (<10% of channels). Fibrin clots were lined by a layer of CD31+ endothelium. Perivascular hypercellular areas stained uniformly with CD31 and less so with VEGFr2. Additionally, focal areas of Ki67+ and CD68+ cells were found in these regions. Expanded stroma contained CD31+ microcapillary networks and stained diffusely with anti-SMA. CONCLUSIONS: Cavernous haemangioma demonstrate clinical features and growth characteristics of a benign mass. Dynamic imaging highlights their slow flow vascular nature. Histologically, the hypercellularity and stromal changes identified can be understood within the pathogenic context of thrombosis and recanalisation in an organised lesion.

Immunohistochemical investigations of orbital infantile hemangiomas and adult encapsulated cavernous venous lesions (malformation versus hemangioma).

PURPOSE: Immunohistochemical studies have begun to advance knowledge regarding the pathogenesis of vascular anomalies in many anatomical regions. However, the immunohistochemical features of most orbital tumors have been overlooked. Therefore, a comparative immunohistochemical study of a series of the 2 most common orbital vascular lesions- infantile hemangioma (IH) and encapsulated cavernous venous lesion (ECVL), the latter also termed cavernous hemangioma or venous malformation-was undertaken. METHODS: Twenty surgically excised orbital tumors diagnosed clinically and histopathologically as IHs (10 cases) or "cavernous hemangioma" (10 cases) were evaluated pathologically and immunohistochemically using hematoxylin and eosin, Alcian blue, Masson trichrome, GLUT-1, CD31, CD34, D2-40, smooth muscle actin (SMA), desmin, and Ki-67 probes. RESULTS: All cases reacted strongly with the traditional blood vessel endothelial markers CD31 and CD34 and were negative for D2-40, a selective marker for lymphatic endothelium. All IH were positive for GLUT-1, and all ECVL were negative for GLUT-1. In IH, SMA (but not desmin) stained a monolayer of pericytes and in ECVL multilaminar smooth muscle vascular mural cells and intravascular (interstitial) stromal cells. Nuclear Ki-67 immunostaining was strongly positive in IH (average of 16.3%) and close to zero in ECVL. CONCLUSIONS: Immunophenotypic results for ECVL and IH demonstrated no overlapping staining patterns. Infantile hemangioma had the classical architecture of capillaries. Because of the constant presence of mural smooth muscle, it was concluded that ECVL is an accurate and descriptive term. However, desmin negativity in ECVL indicates myofibroblastic differentiation rather than full-fledged smooth muscle differentiation. Infantile hemangioma may display ectatic channels as the lesion ages but does not acquire multilaminar smooth muscle walls. Its pericytes lack cytoplasmic filaments and desmin reactivity but are SMA-positive because of the presence of poorly polymerized actin in the cytosol. In IH, Ki-67 positivity was observed in the endothelial cells of the solid and more ectatic regions. In contrast, the virtual absence of Ki-67 positivity in ECVL lends further support for the interpretation that it is more closely related to a malformation than a benign neoplasm.

Angiomyofibroma of the orbit: a hybrid of vascular leiomyoma and cavernous hemangioma.

PURPOSE: The aim of this study was to describe a novel primary orbital vascular tumor combining elements of a vascular leiomyoma (angioleiomyoma) and a cavernous hemangioma. METHODS: A critical review of clinical records, diagnostic tests, and radiographic studies combined with histopathologic evaluation with standard and special histochemical staining and immunohistochemical investigations was conducted. RESULTS: A 44-year-old man slowly developed 5 mm of well-tolerated relative right proptosis with minimal motility disturbance and no visual decline. Computed tomography and magnetic resonance imaging demonstrated a medial and intraconal rounded mass that perfused slowly and whose anterior surface was well circumscribed. At surgery, the tumor was solid and pink with intersecting white bands and densely attached to surrounding normal tissues. The most adherent apical portion of the mass was left behind after subtotal excision. Histopathologically, only a partial pseudocapsule was discovered. The tumor was composed of cavernous channels, capillary zones, compressed lumens with linear strands of endothelium, and collections of muscular veins devoid of an elastica. Striking smooth muscle actin positivity was identified in disorganized masses of smooth muscle cells in the intervascular spaces and around the cavernous vascular units; these myocytes were intermixed with bundles of interstitial keloidal collagen. The endothelium was CD31 and CD34 positive for vascular endothelium and D2-40 negative for lymphatic endothelium. CONCLUSIONS: The authors have classified this hybrid tumor an angiomyofibroma with low neoplastic potential and features of a malformation. It is a composite variant of cavernous hemangioma associated with a conspicuous proliferation of anomalous disorganized smooth muscle cells (leiomyoma). Most of the lesion lacked a pseudocapsule, which impeded surgical delivery. Incomplete excision is recommended in such cases as preferable to the complications that could ensue from overly aggressive efforts at complete removal, particularly at the orbital apex. Supporting this position is the observation that incompletely excised cavernous hemangioma generally does not recur.

Orbital cavernous haemangiomas: immunohistochemical study of proliferative capacity, vascular differentiation and hormonal receptor status.

BACKGROUND/AIMS: Immunohistochemical characterisation of orbital cavernous haemangiomas (CHs) with respect to proliferative capacity, hormone receptor status and vascular differentiation. METHODS: Eleven cases of orbital CHs were reviewed. Immunohistochemical stains for Mib-1, proliferating cell nuclear antigen (PCNA), Bcl-2, estrogen and progesterone receptors (ER & PR), CD31, D2-40, and VEGF were investigated in 11 specimens. RESULTS: Immunohistochemical staining revealed positivity for PCNA in ten of the 11 cases (91%). Bcl-2 was positive in 8 cases (73%). VEGF and PR were each weakly positive in 3 cases. All cases were negative for Mib-1, ER and D2-40. The staining was localized around the endothelium. CONCLUSION: This is the first study to characterise in detail the immunohistochemical features of orbital CHs. The proliferative markers PCNA and Mib-1 show discordant expression in these lesions and the expression of PCNA and Bcl-2 in the absence of Mib-1 is indicative of low proliferative potential. Small subsets of these tumors express PR and VEGF, which may partly explain the proliferative capacity of some orbital CHs.

Sinusoidal hemangioma of the arm: case report and review of literature.

Sinusoidal hemangioma is a rare variant of cavernous hemangioma that develops more frequently subcutaneous, often in the extremities. We report the case of a 19-year-old patient three times operated for a recurrent soft tissue tumor, located in the distal third of the antero-medial face of the right arm. Treatment was surgical and consisted of microsurgical excision of a tumor with dermal and intramuscular location. Histopathological analysis showed a nodular proliferation of interconnected thin-walled blood vessels, sinusoidal growth pattern and the presence of pseudopapillary structures. Immunohistochemical investigations were positive for CD31, CD34 and Ki67 index decreased, confirming the benign nature of vascular proliferation.

[Clinicopathologic study of giant cell angioblastoma].

OBJECTIVE: to study the clinicopathological features, imaging characteristics, immunophenotypes and differential diagnosis of giant cell angioblastoma (GCAB). METHODS: a case of GCAB in the left middle-upper tibia and fibula was studied by light microscopy, X-ray and CT imaging, immunohistochemistry. RESULTS: X-ray and CT imaging showed a clearer lesion in the left middle-upper tibia than in the ipsilateral fibula with enlarged ostealleosis and increased inhomogeneously medullary cavity density, irregular thickening of cortical bone, local cortical default at the inner edge, soft tissue swelling around the abnormal bone. Histologically, tumor tissue was located between the bone trabeculae by nodular, linear and plexiform aggregates of oval-to-spindle cells, large mononucleate cells and multinucleate giant cells with prominent nucleoli and abundant granular eosinophilic cytoplasm. Some aggregates had uncentain amount of discernible lumens, either empty or containing few erythrocytes. A concentric arrangement of oval-to-spindle Cells around small-caliber vascular structures together with collagen fiber contributed to a so-called 'onion-skin' arrangement. The background showed a loose mesenchymal stroma formed of some inconspicuous spindle-fibroblast-like cells, stellate-shape mesenchymal cells, a moderate mononuclear inflammatory cell infiltrate and scattered mast cells. Immunophenotype showed the tumor cells and giant cells strongly positive for vimentin. A good many oval-to-spindle cells stained markedly for CD31 and CD34, but weakly for FVIII, while the giant cells are highlighted instead by CD68, occasionally, very few giant cells showed positive focally for FVIII, a-SMA decorated notedly the cells surrounding the endothelium-like cells but weakly positive in some other tumor cells. CONCLUSION: GCAB is a rare, locally infiltrative but slow growing neoplastic angiogenesis with unique morphological characteristics during infancy, which may occur not only in the skin, mucosa, subcutis and deep soft tissue but also in the bone.