Pyogenic granuloma, an impaired wound healing process, linked to vascular growth driven by FLT4 and the nitric oxide pathway

Effectiveness and safety of the 1064 nm long-pulsed Nd: YAG laser for treating pyogenic granuloma children: a retrospective study of 30 patients

Pyogenic Granuloma (PG) is a benign vascular tumor with multiple treatment; current therapies mainly focus on laser therapy but its' use in children was rarely been reported. This retrospective study aimed to analyze the effectiveness and safety of the 1064 nm long-pulsed Nd: YAG laser for treating PG among children attending our Dermatology Laser Clinic to take laser therapy. The researchers collected data of 30 Chinese pediatric PG patients treated with 1064 nm long-pulsed Nd: YAG laser with fluences of 85-130 J/cm2 and pulse width of 10-40 and pulse of 1-4 at one-month intervals. Total treatment ranged from one to two sessions. A assessment of clinical efficacy was made by two physicians through measuring the long and short diameters of PG in standard photos to compute the changes in the PG volume. Based on the pretreatment and post-treatment photos, a 5-point grading scale was used for the evaluation of pigment clearance: 5 for complete (95-100%), 4 for excellent (75-94%), 3 for good (50-74%), 2 for fair (25-49%), and 1 for poor (0-24%). Adverse reactions such as bleeding, scar and pigmentation were recorded during the follow-up visit after treatment. Among these patients, 28 recovered after a single treatment, and 2 received two treatments. After the first laser treatment, there was a significant reduction in grading scores(p < 0.0001), accompanied by a notable improvement in physician visual evaluation. There was recurrence-free during 6 months of follow-up in all patients. Only 1 patient was observed with a scar. Post-inflammatory hyperpigmentation after treatment was observed in 2 patients which improved within 3 months. Hypopigmentation was not found after treatment. The 1064 nm long-pulsed Nd: YAG laser is an effective and safe approach for treating PG in children.

Pigmented pyogenic granuloma of the cornea and conjunctiva: a rare bilateral presentation

Pyogenic granuloma, also known as lobular capillary hemangioma, is a benign vascular lesion that primarily affects the skin and mucous membranes. It is not pyogenic; nor is it granulomatous. It typically arises in response to local trauma or surgery, irritation, hormonal changes, or chronic inflammation, and it sometimes occurs spontaneously. The occurrence of pigmented pyogenic granuloma in the conjunctiva and cornea without any history of trauma or surgery is extremely rare, particularly in children. We report the clinical presentation, diagnostic evaluation, and successful management of bilateral biopsy-proven conjunctival and corneal pigmented isolated pyogenic granuloma in an 11-year-old girl. No signs of recurrence were seen at the 3-months follow-up.

Conservative Management of Giant Pyogenic Granuloma Post Strabismus Surgery: A Case Report and Literature Review

Ocular pyogenic granuloma is a benign vascular tumor that occurs primarily in children. Treatment options for pyogenic conjunctival granulomas include topical steroids, topical timolol, surgery, cryotherapy, and electrocautery. Patients with giant pyogenic granulomas are usually treated with surgical intervention. In this case, a 13-year-old Egyptian girl developed a giant pyogenic granuloma after strabismus surgery. Topical steroids showed a poor response and failed to demonstrate any improvement. While on timolol, the granuloma completely regressed, with no signs of recurrence. Despite the usual surgical approach to the treatment of purulent giant granulomas, we believe that topical timolol can be the preferred option as a noninvasive alternative therapy since it is considered safe when compared to the potential risks of topical steroid therapy or surgical exposure.

MEK inhibition reduced vascular tumor growth and coagulopathy in a mouse model with hyperactive GNAQ

Activating non-inherited mutations in the guanine nucleotide-binding protein G(q) subunit alpha (GNAQ) gene family have been identified in childhood vascular tumors. Patients experience extensive disfigurement, chronic pain and severe complications including a potentially lethal coagulopathy termed Kasabach-Merritt phenomenon. Animal models for this class of vascular tumors do not exist. This has severely hindered the discovery of the molecular consequences of GNAQ mutations in the vasculature and, in turn, the preclinical development of effective targeted therapies. Here we report a mouse model expressing hyperactive mutant GNAQ in endothelial cells. Mutant mice develop vascular and coagulopathy phenotypes similar to those seen in patients. Mechanistically, by transcriptomic analysis we demonstrate increased mitogen activated protein kinase signaling in the mutant endothelial cells. Targeting of this pathway with Trametinib suppresses the tumor growth by reducing vascular cell proliferation and permeability. Trametinib also prevents the development of coagulopathy and improves mouse survival.

Successful management of tracheal lobular capillary hemangioma with arterial embolization followed by electrosurgical snaring via flexible bronchoscopy in an 11-year-old boy: A case report and literature review

Lobular capillary hemangioma (LCH), previously known as pyogenic granuloma, is a benign vascular lesion commonly found within the oral and nasal cavities. However, it is rarely encountered within the trachea, especially in pediatric patients, where it manifests as hemoptysis, cough, and wheeze, and is frequently misdiagnosed as bronchitis or asthma. There is limited literature on the presentation, behavior, and management of tracheal LCH. Herein, we describe a rare case of tracheal LCH in an 11-year-old boy with a history of hemoptysis, which was successfully managed with arterial embolization followed by electrocautery loop snaring via flexible bronchoscopy. No complications occurred during and after the procedure. A review of the relevant literature is also provided. Our case is unique, given the therapeutic strategy utilized for pediatric tracheal LCH, and reminds physicians to be aware of tracheal LCH in the differential diagnosis for hemoptysis.

The Vasculature in Pulmonary Fibrosis

Purpose of Review

The current paradigm of idiopathic pulmonary fibrosis (IPF) pathogenesis involves recurrent injury to a sensitive alveolar epithelium followed by impaired repair responses marked by fibroblast activation and deposition of extracellular matrix. Multiple cell types are involved in this response with potential roles suggested by advances in single-cell RNA sequencing and lung developmental biology. Notably, recent work has better characterized the cell types present in the pulmonary endothelium and identified vascular changes in patients with IPF.

Recent Findings

Lung tissue from patients with IPF has been examined at single-cell resolution, revealing reductions in lung capillary cells and expansion of a population of vascular cells expressing markers associated with bronchial endothelium. In addition, pre-clinical models have demonstrated a fundamental role for aging and vascular permeability in the development of pulmonary fibrosis.

Summary

Mounting evidence suggests that the endothelium undergoes changes in the context of fibrosis, and these changes may contribute to the development and/or progression of pulmonary fibrosis. Additional studies will be needed to further define the functional role of these vascular changes.

Immunoexpression of proliferation and apoptosis markers in oral vascular anomalies

The biological behavior of lesions is highly dependent on the imbalance between their proliferative and apoptotic capacity. This study evaluated a correlation between the proliferative and apoptotic rates of different oral vascular anomalies (VAs) by analyzing the immunoexpression of proliferation (Ki-67) and apoptosis (Bcl-2 and Bax) markers in endothelial cells of 20 cases of GLUT-1 positive infantile hemangiomas (IHs), 20 cases of pyogenic granulomas (PGs) and 20 cases of vascular malformations (VMs). Immunoexpression analysis of Ki-67, Bcl-2 and Bax revealed a lower median percentage of positive cells in VMs cases compared to IHs and PGs cases (P <0.001). The Wilcoxon signed-rank test showed significantly higher percentages of immunostaining for Bax than for Bcl-2 in IHs (P = 0.048). In the group of PGs, a positive correlation was observed between the immunoexpressions of Ki-67 and Bax (r = 0.476; P = 0.034). Although oral IHs, PGs and VMs present similar clinical and histopathological features, each of these lesions has its etiopathogenic particularities. The results of this study suggest that different biological behaviors of VAs may be related to differences in the proliferative and apoptotic profiles of their endothelial cells.

Large Lobular Capillary Hemangioma Associated with Ingrown Toenail: Histopathological Features and Case Report

Lobular capillary hemangioma (LCH-PG) is a type of pyogenic granuloma characterized by proliferating blood vessels that resemble conventional granulation tissue. Granulation tissue is very often seen in association with ingrown toenails. Despite the close relationship between both entities, LCH-PG shows clinically different behaviors, such as rapid growth and frequent recurrence. Currently, it is unknown exactly how the different etiological factors contribute to the formation of differences between entities. We present a case of a large LCH-PG associated with chronic onychocryptosis in a 26-year-old man. Histopathological features included extensive signs of ulceration, hyperkeratosis, and patchy epidermal acanthosis with the presence of fibrous septa with lobular areas beneath the ulcerative area. The presence of stroma with a marked proliferation of blood vessels with wall thickening and mixed-type inflammatory changes was also characteristic. In advanced stages of onychocryptosis, as presented here, conventional granulation tissue or pyogenic granuloma can be clinically difficult to distinguish from other benign or malignant neoplasms. Histological examination is mandatory, and excisional biopsy can provide a definitive diagnosis.

Posttraumatic Vascular Anomalies in Hand Surgery-A Case-based Approach

The field of vascular anomalies (VA) has been subject to changes during the last few decades. The current classification of the International Society for the Study of Vascular Anomalies (ISSVA) offers a simple diagnostic structure. Hand surgeons commonly appear to have limited exposure to VA. Already recognized for more than 120 years, pyogenic granuloma (PG) is by far the most commonly described VA by different disciplines with accordingly diverse treatment strategies and theories behind it. Arteriovenous fistula (AVF), venous aneurysms (VAN), and venous malformations (VM) are, however, rare in hand surgery. With a compilation of four illustrative cases of posttraumatic entities such as AVF, VAN, VM, and PG, we would like to highlight possible daily exposure to VA in the general hand surgery practice. We discuss diagnostic and therapeutic options as well as the current literature with focus on posttraumatic VA.

Hyperbaric oxygen therapy acts as an alternative method in treating injection-induced nodules

BACKGROUND

Cosmetic injection-induced nodules are tricky to handle in the clinic.

AIMS

We reported a case of injection-induced nodule receiving the experimental treatment of hyperbaric oxygen therapy (HOT).

PATIENT

A woman presented with multiple red solid nodules on the neck after receiving mesotherapy conducted by syringe. Ultrasound examination showed multiple thickened inflammatory skin tissues on the neck. Pathological biopsy results showed epithelioid granulomas in the dermis, within which there were degenerative necrosis and foreign bodies in the center and multinucleated giant cells around. The bacteria tests remained negative. Diagnosed with foreign body granuloma, the patient rejected the resection or steroids, but willingly took the experimental treatment of HOT instead. After one month, the patient's ultrasound examination showed that the lesion's local hardness got significantly reduced, and the local blood flow increased, indicating the condition improved.

RESULTS

Although the patient's nodule has not been eliminated, some improvements have been achieved. So far there has no case report on HOT treating injection-induced nodules in the literature.

CONCLUSION

HOT may be considered as a potential alternative when other treatment options cannot be implemented. More research is needed in this field.

Multiple Erythematous Nodules: An Intriguing Entity

Pyogenic granuloma (PG), also called a lobular capillary hemangioma, is a benign vascular proliferation of skin or mucous membrane. It classically presents as a solitary friable nodule over the face or distal extremities. Multiple disseminated PG is a rare form generally reported after trauma such as burn injury. We report two cases of spontaneous development of multiple localized PGs in immunocompetent individuals.

An Uncommon Presentation of Pyogenic Granuloma

Benign vascular neoplasms are common clinical problems encountered in the practice of primary care. Pyogenic granulomas are one of the most common benign vascular lesions in young adults. Although the physiopathological mechanism for the development of this condition is still not well understood, it has been commonly associated with several triggers such as treatment with retinoids, biological agents, invasive cutaneous therapies and trauma. The development of pyogenic granulomas on sites of vascular malformations like port wine stains has been described in the literature to occur rarely. Most of these types of cases have been studied to occur in the setting of pregnancy and after cryotherapy or pulsated laser therapy. The aim of this article is to present the case of a 21-year-old man with a recent appearance of a pyogenic granuloma within an underlying port wine stain in the posterior cervical region without any history of triggers or risk factors. Excision of the vascular lesion was done, and histopathological report confirmed the diagnosis. The objective of this manuscript is to discuss the possible mechanisms involved in the development of this uncommon presentation and to summarize the current literature related to this clinical scenario.

Plump endothelial cells integrated into pre-existing venules contribute to the formation of 'mother' and 'daughter' vessels in pyogenic granuloma: possible role of galectin-1, -3 and -8

INTRODUCTION

Pyogenic granuloma (PG) is a reactive inflammatory vascular lesion of the skin and mucous membranes, characterised by the presence of enlarged venules and seamed and seamless capillaries with plump endothelial cells (EC), and numerous macrophages. EC activation upregulates the synthesis of galectins and induces their translocation to the EC surface promoting angiogenesis and lymphangiogenesis, particularly galectin-1 (Gal-1), Gal-3 and Gal-8. However, the presence and distribution of Gal-1, -3 and -8, as well as their implications in the pathogenesis of PG, has not been considered.

MATERIALS AND METHODS

Eight biopsies from patients diagnosed with PG were selected. The presence of PECAM-1/CD31, IL-1β, VEGF-C, VEGFR-2, VEGFR-3, integrin β1, CD44, fibronectin and Gal-1, -3 and -8 was assessed by immunofluorescence staining using confocal laser scanning microscopy.

RESULTS AND DISCUSSION

Immunostaining revealed that these molecules were present in the enlarged venules with plump ECs, in some macrophages and other immune cells. We propose that macrophages release VEGF-A and VEGF-C inducing VEGFR-2/VEGFR-3 expression and activation, leading macrophages to transdifferentiate into plump ECs that might integrate into pre-existing venules, contributing to the formation of enlarged venules with transluminal bridges and capillaries. EC activation, induced by certain cytokines, has been shown to stimulate galectin expression and changes in the cellular localisation through association and activation of specific EC surface glycoproteins. Therefore, it is plausible that Gal-1, -3 and -8, acting in a concerted manner, could be mediating the transdifferentiation of macrophages into plump ECs and facilitating their migration and incorporation into the new vessels.

LAY SUMMARY

In this study, immunostaining of pyogenic granuloma (PG) tissue sections showed immunoreactivity for PECAM-1/CD31, IL-1β, VEGF-C, VEGFR-2 and VEGFR-3, and galectin-1, -3 and -8 in enlarged venules with plump endothelial cells (EC), as well as in some macrophages and other immune cells. Interestingly, enlarged and thin-walled transient vessels lined by PECAM-1/CD31 and VEGFR-2 immunopositive ECs that form from pre-existing normal venules in response to VEGF-A (called 'mother' vessels [MV]) and that undergo intraluminal bridging evolving into various types of capillaries (called 'daughter' vessels [DV]) have been observed in benign and malignant tumours, in physiological and pathological angiogenesis as well as in vascular malformations, suggesting an important role for VEGF-A and VEGFR-2 in such a process. However, it is not only the mechanisms by which the MVs evolve in different types of DVs that remains to be elucidated, but also whether the cells that form intraluminal bridges proceed from locally activated ECs or whether they are derived from bone marrow precursors or from resident macrophages.Given that the formation of homodimers by Gal-1 and Gal-8 and pentamers by Gal-3 to generate gal-glycan lattices at the cell surface and in the extracellular space has been shown, it is possible that in PG tissue Gal-1, -3 and -8, through their binding partners, form a supramolecular structure at the surface of ECs and plump ECs, macrophages and in the extracellular space that might be mediating the transdifferentiation of macrophages into plump ECs and facilitating the migration and incorporation of these cells into the pre-existing venules, thus contributing to the formation of MVs and DVs.

[Classification of vascular tumours and vascular malformations. Contribution of the ISSVA 2014/2018 classification]

The study of vascular anomalies, "angiomas", vascular tumours and vascular malformations is made difficult by the great variety and confusion of the names used in the literature for these diseases, some of which are rare. The great merit of the classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA), adopted in 2014 and modified in 2018, is to propose a unambiguous nomenclature and to try to group these lesions in a logical way, contrasting with the lists of the usual "classifications". This classification is based on the distinction between proliferative lesions (tumours and reactive lesions) and those which are due to a congenital anomaly of vascular morphogenesis (vascular malformations). It incorporates recent data on the molecular causes of these diseases. The major groups of lesions recognised in this classification will be presented and some lesions of interest briefly discussed. This classification aims to be usable by all medical specialties and applicable to all tissues and organs, even if efforts are still needed to integrate organ-specific names in order to unify the nomenclature and eliminate confusion. Even if it does not solve all the problems in this complex field, the unification of the nomenclature is a major contribution of this classification and pathologists are strongly encouraged to refer to it in daily practice.

Pyogenic granuloma-like Kaposi sarcoma presenting in an HIV-negative man who has sex with men

A 36-year-old immunocompetent man who have sex with men first presented to the plastics team with an ulcerating lesion on his left first toe. The lesion was suggestive of pyogenic granuloma (PG) clinically and histologically. Two years later, the same patient presented to the dermatology clinic with a new erythematous lesion with intermittent bleeding on the left second toe. Clinically, this lesion was suggestive of another PG. However, the histology of the skin curettage revealed part of a PG merging with an atypical spindle cell proliferation with characteristic 'sieve-like' appearance in keeping with Kaposi sarcoma. This was confirmed with human herpesvirus-8 immunohistochemistry staining. PG-like Kaposi sarcoma is an uncommon variant of Kaposi sarcoma. Often not considered clinically or histologically, a deep skin biopsy is essential to establish the right diagnosis. Our case highlights the need to consider Kaposi sarcoma as a differential diagnosis in all patients, including HIV-negative individuals, presenting with PG-like lesions.

Pediatric Tracheal Lobular Capillary Hemangioma: A Case Report and Review of the Literature

Chronic cough is a common complaint in the pediatric population and can have many different etiologies. We present a rare case of a tracheal lobular capillary hemangioma (LCH), also known as pyogenic granuloma, causing chronic cough in a child. In this case, the tracheal LCH was managed successfully with laser ablation. A review of the literature reveals only 2 other reported pediatric cases of tracheal LCH. Laryngoscope, 131:1729-1731, 2021.

Intraoperative mitomycin C and cryotherapy as adjunct therapy for recurrent lobular capillary haemangioma of conjunctiva

Recurrence of lobular capillary haemangioma of conjunctiva after surgical excision is rare but sometimes it may be difficult to manage multiple recurrences. A 31-year-old female patient presented with recurrent polypoid conjunctival lobular capillary haemangioma. Excisional biopsy was performed, followed by eye drop mitomycin C 0.04% four times a day for 1 week postoperatively. She reported again after 3 months with recurrence of vascular elongated nodular lesion. Excision of the mass with application of mitomycin C 0.02% intraoperatively for 1 min and cryotherapy using double thaw technique of the peripheral conjunctival margin was done. The histopathological examination confirmed the recurrence of lobular capillary haemangioma. On review, 1 year after treatment there was no evidence of recurrence. A combined use of cryotherapy and intraoperative mitomycin C as adjunctive therapy after surgical excision can successfully prevent further recurrence without any adverse effect.

A Sheep in Wolf's Clothing: Lobular Pyogenic Granuloma Masquerading Nodular Amelanotic Melanoma

BACKGROUND:

Tumor masquerading is a common phenomenon seen in clinical dermatology. While amelanotic melanoma is known to simulate pyogenic granuloma, a benign vascular tumour, the contrary has been reported exceptionally scarce.

CASE PRESENTATION:

We present a 52-year-old woman with a slow-growing lesion on her right flank, which developed over 12 months. On examination, we observed a large exophytic, easily bleeding tumour on the right flank, that resembled amelanotic malignant melanoma. Histologic analysis after complete excision of the lesion confirmed a pyogenic granuloma of the lobular capillary hemangioma subtype. In the present case masquerading of the lesion went to the better site after histologic investigations despite the delay of diagnosis caused by the patients.

CONCLUSION:

Nevertheless, the diagnosis of uncertain lesions needs a rapid histologic analysis to gain the best possible prognosis for the patient.

Efficacy of Nd-YAG laser for treatment of pyogenic granuloma on the fingers and toes

Pyogenic granuloma (PG) is a common benign vascular proliferation which often occurs on the head, neck, hands, and feet. Among the various treatment options for PG, surgical excision is the most effective treatment which offers the lowest overall recurrence rates and also provides the exact diagnosis. However, it could have difficulties to do the surgery when lesions are located on the fingers and toes, especially very near to the nails, so laser may be a very good alternative choice. In this article, we evaluated the clinical efficacy and safety of neodymium-yttrium aluminum garnet (Nd:YAG) laser for treatment of PG located on the fingers and toes. Twenty-one patients with 21 PGs located on the fingers and toes were treated by multispot Nd-YAG laser. We chose monopulse (pulse width 10.5-13.5 ms; energy 100-125 J/cm²); treatment interval was 3-4 weeks. All lesions disappeared after one or two treatments. There was no apparent scar formation, no impact on the function of the fingers and toes, no damage to nail growth, and no recurrence in more than 12-month follow-up. Nd-YAG is an effective and safety treatment option for treatment of PG located on the fingers and toes.

Expression of embryonic stem cell markers in pyogenic granuloma

BACKGROUND

Recent description of hemangioblastic blood islands within pyogenic granuloma (PG) has led us to investigate the expression of embryonic stem cell (ESC) markers in this tumor.

METHODS

In this study we examined the expression of ESC markers, OCT4, SOX2, STAT3 and NANOG in PG samples from 11 patients, by immunohistochemical (IHC) staining, NanoString analysis and in situ hybridization (ISH).

RESULTS

IHC staining demonstrated the expression of pSTAT3, OCT4, SOX2 and NANOG by the endothelium of the microvessels in PG whilst pSTAT3, SOX2 and NANOG were also expressed by cells in the interstitium, outside of the microvessels. NanoString and ISH analysis showed mRNA expression for STAT3, OCT4 and NANOG in PG.

CONCLUSIONS

The expression of the ESC markers, OCT4, SOX2, pSTAT3 and NANOG, suggests the endothelium of PG displays a primitive phenotype. Cells in the interstitium expressing pSTAT3, SOX2 and NANOG may represent a more downstream derivative of the primitive endothelium, or a separate population. The primitive nature of the endothelium and cells in the interstitium reveals novel insights into the biology of PG. To the best of our knowledge, this is the first demonstration of the expression of ESC markers in PG, implying the presence of a hematopoietic stem cell population.

Eruptive disseminated pyogenic granulomas following lightning injury

BACKGROUND

Pyogenic granuloma (PG) is a common benign acquired vascular tumor. It classically presents as a solitary friable nodule on the face or distal extremities. Disseminated eruption is rare and can occur spontaneously or secondary to various triggers, including burn injury. To date, the literature reports only 13 cases of eruptive PGs following burn injury, most from exposure to boiling milk or water. We report the first case of disseminated eruptive PGs following a lightning injury.

CASE

A 17-year-old previously healthy boy developed second- and third-degree burns following lightning injury. Two weeks later, he developed widespread dark-purple polypoid exophytic tumors ranging from 1 to 10 cm in diameter extending beyond the limits of the initial burn injury. The lesions were friable and often formed erosions and crusts. The patient was otherwise well and laboratory and microbiological investigations were normal. Excisional biopsy of a lesion was diagnostic of PG and the patient was treated with surgical excision of the lesions, without recurrence.

CONCLUSION

The exact pathogenesis of multiple PGs remains unknown. Several pathogenic mechanisms have been suggested, including production of angiogenic factors that stimulate endothelial proliferation and formation of minute arteriovenous fistulas by trauma.

Vascular Anomalies Classification: Recommendations From the International Society for the Study of Vascular Anomalies

Vascular anomalies represent a spectrum of disorders from a simple "birthmark" to life- threatening entities. Incorrect nomenclature and misdiagnoses are commonly experienced by patients with these anomalies. Accurate diagnosis is crucial for appropriate evaluation and management, often requiring multidisciplinary specialists. Classification schemes provide a consistent terminology and serve as a guide for pathologists, clinicians, and researchers. One of the goals of the International Society for the Study of Vascular Anomalies (ISSVA) is to achieve a uniform classification. The last classification (1997) stratified vascular lesions into vascular malformations and proliferative vascular lesions (tumors). However, additional disease entities have since been identified that are complex and less easily classified by generic headings, such as capillary malformation, venous malformation, lymphatic malformation, etc. We hereby present the updated official ISSVA classification of vascular anomalies. The general biological scheme of the classification is retained. The section on tumors has been expanded and lists the main recognized vascular tumors, classified as benign, locally aggressive or borderline, and malignant. A list of well-defined diseases is included under each generic heading in the "Simple Vascular Malformations" section. A short definition is added for eponyms. Two new sections were created: one dealing with the malformations of individually named vessels (previously referred to as "truncular" malformations); the second groups lesions of uncertain or debated nature (tumor versus malformation). The known genetic defects underlying vascular anomalies are included in an appendix. This classification is meant to be a framework, acknowledging that it will require modification as new scientific information becomes available.

Giant pyogenic granuloma in a patient with chronic lymphocytic leukemia

Pyogenic granuloma, also known as lobular capillary hemangioma, is a common benign vascular proliferative lesion that can present at any age on the skin or mucous membranes. Most lesions do not exceed 2 cm, but there are a handful of giant cutaneous pyogenic granulomas that have been reported, often in individuals with underlying immune dysfunction. Here, we report the first giant pyogenic granuloma in a patient with a hematological malignancy, chronic lymphocytic leukemia.

SiRNA-mediated silencing of VEGFR-3 reduces proliferation, adhesion and migration of colorectal cancer cells

AIM: To investigate the effect of transfection with an adenovirus vector expressing short interfering RNA (siRNA) targeting vascular endothelial growth factor receptor-3 (VEGFR-3) on cell proliferation, adhesion and migration in colorectal cancer cell line LoVo.

METHODS: An adenovirus vector expressing siRNA targeting VEGFR-3 was constructed and transfected into LoVo cells. The expression of VEGFR-3 was detected by RT-PCR and Western blot. Cell proliferation and migration were detected by MTT assay and Transwell assay, respectively.

RESULTS: The expression of VEGFR-3 mRNA and protein was significantly decreased after transfection with the recombinant adenovirus (P < 0.05), compared with the blank control group and negative control group. The proliferation, adhesion and migration of LoVo cells were significantly decreased after transfection with the recombinant adenovirus (P < 0.05).

CONCLUSION: SiRNA-mediated silencing of VEGFR-3 inhibits the proliferation, adhesion and migration of LoVo cells.

Herpes simplex virus type-I and pyogenic granuloma: a vascular endothelial growth factor-mediated association?

Pyogenic granuloma (PG) is a vascular endothelial growth factor (VEGF)-related neoangiogenic process. Minor trauma, chronic irritation, certain drugs and pregnancy may favor PG. Viral triggers have not been reported up to date. A 52-year-old woman with hairy-cell leukemia presented because of a 3-month history of a giant pseudotumoral lesion on her left cheek. All prior antibacterial, antifungal and anti-inflammatory treatments had failed. Histology revealed PG with sparse and isolated epithelial cell aggregates. Immunohistochemistry (IHC) identified herpes simplex virus type-I (HSV-I) antigens in the nuclei and cytoplasm of normal-appearing as well as cytopathic epithelial cells, suggesting a chronic, low-productive HSV infection. No HSV-I signal was evidenced in the endothelial cells of the PG. Furthermore, IHC revealed VEGF in the HSV-I infected epithelial cells as well as within the PG endothelial cells. These results incited oral treatment with valaciclovir, and the PG promptly resolved after 2 weeks. These findings suggest that a chronic HSV-I infection might play an indirect, partial role in neoangiogenesis, presumably via HSV-I infection-related stimulation of keratinocytic VEGF production.