Increased 68 Ga-FAPI Uptake in Capillary Hemangiomas in an Adult Patient

ABSTRACT

A 67-year-old woman was enrolled in our 68 Ga-FAPI PET/CT tumor clinical trial due to her lung adenocarcinoma. The PET/CT scan additionally revealed increased uptake of FAPI in the tongue. Combined with the patient's medical history and the contrast-enhanced CT of the maxillofacial region, it was suspected to be a hemangioma. Subsequently, the patient underwent surgery and was diagnosed with capillary hemangioma of the left side of her tongue.

[Expression and significance of the proteins in TSP-1 and NF-κB signal pathways of infantile capillary hemangioma]

OBJECTIVE

To explore the significance of the relative proteins in thrombin sensitive protein(TSP-1) and nuclear factor kappa B (NF-κB) signal pathways by detecting their expressions in different phases of hemangioma and the relations between them and microvessel density(MVD).

METHODS

Forty cases with hemangioma were randomly selected and divided into proliferative group(n =21) and involutional group(n =19) according to Mulliken standard.The expressions of TSP-1,CD36,p59fyn,Caspase-3,p38MAPK,NF-κBp65,p-IκBα,p-IKKβ,VEGF and CD34 in endothelial cells were detected by immunohistochemistry.The relevance between the proteins in TSP-1 and NF-κB signal pathways and MVD were compared and analyzed respectively.

RESULTS

The expressions of TSP-1,CD36,p59fyn,Caspase-3,p38MAPK in proliferative hemangioma were all lower than those in involutional hemangioma (F=32.582,47.575,11.645,18.824,13.140;P =0.000,0.000,0.002,0.000,0.001).Conversely, the expressions of NF-κBp65,p-IκBα,p-IKKβ,VEGF in proliferative hemangioma were higher than those in involutional hemangioma(F =7.807,6.323,5.988,4.216;P =0.009,0.018,0.021,0.049).Meanwhile,MVD were different between the two groups(F =7.256,P =0.012).The expressions of TSP-1, CD36, p59fyn and MVD showed a negative relationship(rs =-0.420,-0.519,-0.388;P =0.021,0.003,0.034). Conversely, the expressions of NF-κBp65,pvIκBα,VEGF and MVD showed a positive relationship(rs =0.666,0.611,0.515;P =0.000,0.000,0.004).The expression of TSP-1 and NF-κBp65 showed a negative relationship (rs =-0.413,P =0.023).

CONCLUSIONS

TSP-1 signal pathway and NF-κBp65 signal pathway may be interactive in evolution of infantile hemangioma, which has a potential role by effecting the progress of angiogenesis.

Hypothalamic-pituitary-adrenal axis recovery following prolonged prednisolone therapy in infants

CONTEXT

The duration of hypothalamic-pituitary-adrenal (HPA) axis suppression after glucocorticoid treatment is uncertain.

OBJECTIVE

We aimed to determine the duration of HPA axis suppression in prednisolone-treated infants and the age at which circadian variation in salivary cortisol is established in healthy infants.

DESIGN, SETTING, AND PARTICIPANTS

Before the adoption of propranolol treatment by the Vascular Birthmarks Clinic, 12 infants with infantile hemangioma received high-dose prednisolone for 12 to 25 weeks' duration, weaned over 4 to 6 weeks, and ceased at age 21 to 31 weeks. Parents collected serial salivary samples at two time points per day (before first and last feed) until circadian variation in salivary cortisol (measured by radioimmunoassay) was observed, when a confirmatory 1 μg Synacthen test was performed. Ten healthy control infants had serial salivary cortisol measurements to determine the age at which circadian variation is established.

MAIN OUTCOME MEASURE

We defined circadian variation as evening salivary cortisol <50% of the early morning level on two consecutive sampling weeks.

RESULTS

Circadian variation appeared within 6 weeks (median 2.7, range 1.4-5.4) of prednisolone cessation. All confirmatory Synacthen tests were normal (peak serum cortisol >600 nmol/L) and were performed within 12 weeks of prednisolone cessation. Healthy controls developed circadian variation at median 16 weeks of age (range 8-24).

CONCLUSION

HPA recovery occurred within 6 to 12 weeks, shorter than empirical recommendations, to give stress cover for 6 to 12 months. Reduced duration of stress-cover precautions may reduce parental anxiety and side effects from unnecessary glucocorticoid use. Healthy control infants established circadian variation in salivary cortisol between 2 and 6 months of age.

Neuropilin-2 and vascular endothelial growth factor receptor-3 are up-regulated in human vascular malformations

Despite multiple previous studies in the field of vascular anomalies, the mechanism(s) leading to their development, progression and maintenance has remained unclear. In this study, we have characterized the expression levels of vascular endothelial growth factors and their receptors in 33 human vascular anomalies. Analysis with quantitative real-time PCR and gene-specific assays showed higher expression of neuropilin-2 (NRP2) and VEGF-receptor-3 (VEGFR-3) mRNAs in vascular malformations (VascM) as compared to infantile hemangiomas (Hem). In addition, the expression levels of PlGF and VEGF-C mRNA were significantly higher in venous VascM when compared to the other VascM and Hem. Higher expression of NRP2 and VEGFR-3 were confirmed by immunohistochemistry. To further study the importance of NRP2 and VEGFR-3, endothelial cell (EC) cultures were established from vascular anomalies. It was found that NRP2 and VEGFR-3 mRNA levels were significantly higher in some of the VascM ECs as compared to human umbilical vein ECs which were used as control cells in the study. Furthermore, adenoviral delivery of soluble decoy NRP2 prevented the proliferation of ECs isolated from most of the vascular anomalies. Our findings suggest that NRP2 functions as a factor maintaining the pathological vascular network in these anomalies. Thus, NRP2 could become a potential therapeutic target for the diagnosis and treatment of vascular anomalies.

[Pulmonary capillary hemangiomatosis: a clinicopathologic analysis of 2 cases with review of literature]

OBJECTIVE

To investigate the clinicopathologic features of pulmonary capillary hemangiomatosis (PCH).

METHODS

The clinical and pathologic profiles of 2 PCH cases were evaluated. Immunohistochemical study (EnVision method) was performed on fixed tissues. The biologic behavior was analyzed with follow-up data.

RESULTS

The main presenting symptom was dyspnea. Chest radiography of the two cases depicted diffuse, ground-glass nodules, accompanied by enlarged central pulmonary arteries. Microscopically, the most distinctive feature was proliferation of capillary channels within pulmonary interstitium and alveolar walls, accompanied by muscularization of arterioles. Immunohistochemical study showed an abundance of mast cells in the lesion, and staining for platelet-derived growth factor receptor-beta (PDGFR-β) localized to vascular smooth muscles surrounding the proliferating capillaries and the mast cells. The index of Ki-67 was less than 1 percent and the p53 was negative.

CONCLUSIONS

PCH is a rare vascular proliferative disease of yang patients. Increased number of mast cell and the up-regulation of PDGFR-β may suggest mechanism for PCH. The clinical and radiologic diagnosis of PCH can be very difficult, and the histological examination is regarded as the most reliable means to establish the diagnosis. Pathologists should improve their knowledge on PCH.

[The role of PD-ECGF and VEGF in proliferative and involuted mechanism of the infantile capillary hemangiomas]

OBJECTIVE

To explore the relation between the expressions of PD-ECGF and VEGF and the evolution of capillary hemangioma, so as to provide theoretical basis for treatment.

METHODS

Fourty cases with capillary hemangioma, proved by pathologic method, were randomly selected and divided into proliferative (n=22) and involuted groups (n=18), according to the Mulliken standard. 8 specimens from 8 children with prepuce operation were used as control group. All the specimens were fixed, embedded and underwent HE staining. The expression of PD-ECGF, VEGF and CD34 in endothelial cells were detected by immunohistochemistry. The microvessel-density (MVD) was also calculated. The results were analyzed by SPSS12.0.

RESULTS

The positive expression rates of PD-ECGF and VEGF were 95.45% (21/22) and 86.36% (19/22) in proliferative hemangioma, 77.78% (14/18) and 66.67% (12/ 18) in involuted hemangioma, 37.50% (3/8) and 37.50% (3/8) in normal skin. MVD in proliferative and involuted hemangioma and normal skin was 93.68 +/- 20.56, 51.94 +/- 20.73 and 17.50 +/- 5.30, respectively. There was a significant difference in PD-ECGF expression and MVD between the proliferative and involuted groups, or between the hemangioma and control groups (P < 0.05). The VEGF was significantly different between the proliferative and involuted groups, or between the proliferative and control groups (P < 0.05), but not between the involuted and control groups (P > 0.05). The expression of VEGF, PD-ECGD and MVD showed a positive relationship.

CONCLUSIONS

PD-ECGF and VEGF have a synergetic effect in the proliferation of micro-vessels. PD-ECGF may enhance the activity of thymidine phosphorylase. They play an important role in the proliferation and involution of hemangioma.

An experimental study on the therapy of infantile hemangioma with recombinant interferon γ

BACKGROUND/PURPOSE

The purpose of this investigation was to study the effect of interferon γ (IFN-γ) in the treatment of infantile hemangioma.

METHODS

Hemangioma tissue excised from a 4-month-old female infant who underwent surgery were separated into small nubs (4 × 4 × 5mm(3)) and implanted subcutaneously into nude mice (2 nubs per mouse). Thirty-two surviving hemangioma nubs were randomly divided into 2 groups, an IFN-γ-administered group (16) and a control group (16). Interferon γ or saline solution was injected subcutaneously, and the growth of hemangioma in the nude mice was monitored. Proliferation and apoptosis of hemangioma were tested by immunohistochemistry and real-time polymerase chain reaction.

RESULTS

Seven days after IFN-γ injection, the hemangiomas in the IFN-γ-administered group were significantly smaller than that in the control group (P < .01). The proliferation cytokine Ki-67 mRNA in the IFN-γ group was significantly lower than that in the control group (P < .05). DAPK-1 mRNA in the IFN-γ group was significantly higher than that in the control group (P < .05). Cell apoptosis expression in the IFN-γ group was significantly more than that in controls (P < .05).

CONCLUSIONS

Exogenous IFN-γ can treat hemangioma effectively in a nude mice model. Its mechanism was closely related to both inhibition of hemangioma proliferation and acceleration of its apoptosis.

A rare neoplasm of the testis: capillary hemangioma

Intratesticular vascular neoplasms are extremely rare tumors and mostly seen in children or young adults. We reported a case of capillary hemangioma of the testis to attract attention to testicular hemangioma and also to prevent invasive surgery of the testis. The patient was an 18-year-old boy with a testicular mass. Scrotal sonography revealed a varicocele in the left testis and a simple cyst in the left epididymis. There was a solid hypoechoic neoplastic area 75 mm in diameter in the right testis. The laboratory findings including tumor markers and serum levels of alpha-fetoprotein and beta-human chorionic gonadotrophin were normal. The patient underwent right orchiectomy and the pathology diagnosis was capillary hemangioma. Testicular neoplasms derived from connective tissue, blood vessels and musculature are uncommon and intratesticular tumors of vascular origin are extremely rare. There are only 21 cases reported in the literature. The pathologists and the surgeon have to be aware of this entity as the prognosis of the neoplasm determines the method of surgery. Capillary hemangioma of the testis can be similar to malignant testicular tumors on clinical presentation, as well as on ultrasonography and magnetic resonance imaging. Although it is impossible to differentiate a hemangioma from a seminoma before the operation, intraoperative frozen study may be helpful in the differential diagnosis. Frozen section must be performed if the neoplasm has significant vascular proliferation identified by Doppler sonography. Because of the benign nature of this lesion, conservative surgical treatment by means of tumor enucleation with preservation of the testis is possible if intraoperative frozen section examination can be performed.

Haemogenic endothelium in infantile haemangioma

BACKGROUND

Proliferating infantile haemangioma (IH) is a tumour of the microvasculature composed predominantly of immature endothelial cells. The origin of IH is unclear, but it has been shown to express markers of both endothelial and haematopoietic lineages, and a role for endothelial progenitor cells in the aetiology of IH has been suggested. Haemangioblasts are precursors of both endothelial and haematopoietic cells, and their characterisation has identified the expression of cell surface and intracellular proteins that collectively can be used for assigning a haemangioblast phenotype.

METHODS

The authors used immunohistochemical staining to characterise the expression of primitive haematopoietic-associated proteins in proliferating IHs.

RESULTS AND DISCUSSION

The authors show that the cells forming the capillary endothelium express markers associated with primitive haematopoietic cells. Additionally, many of these cells express the transcription factors brachyury and GATA-2, indicating a primitive mesodermal origin. They hypothesise that the immature capillaries in IH are derived from primitive mesodermal cells with haemangioblastic differentiation capabilities. The expression of primitive mesodermal, endothelial and haematopoietic markers by the cells forming the endothelium suggests that the immature capillaries that predominate in proliferating IH are a haemogenic endothelium phenotype, derived from haemangioblasts.

Expression of calcitonin receptor-like receptor in human vascular tumours

BACKGROUND

Vascular tumours such as Kaposi's sarcoma and capillary haemangioma are characterised by abnormal vascularisation and proliferation of endothelial cells or neoplastic cells. Adrenomedullin, a potent vasodilative peptide, and its receptor, calcitonin receptor-like receptor (CRLR), play an important part in angiogenesis.

AIM

To establish whether this system also plays a part in vascular diseases, showing abnormal proliferation such as vascular tumours.

METHODS

CRLR expression was investigated in several specimens of Kaposi's sarcoma and other vascular tumours, using immunohistochemical analysis with a previously described CRLR-specific polyclonal antibody and reverse transcriptase-polymerase chain reaction.

RESULTS

Intense and specific CRLR-immunoreactive staining of neoplastic cells was observed in all specimens, which was of greater intensity than similar staining of adjacent normal endothelium.

CONCLUSIONS

CRLR is expressed in vascular tumours and, with adrenomedullin, may have a role in neoplastic vascular growth.

Pulmonary capillary hemangiomatosis: an immunohistochemical analysis of vascular remodeling

QUESTION OF STUDY: Pulmonary capillary hemangiomatosis (PCH) is an extremely rare cause of severe pulmonary hypertension. It is characterized histologically by exuberant proliferation of capillaries that often invade alveolar septae, bronchial walls, and pleura. Expression of vascular remodeling markers in PCH is not known.

MATERIALS/PATIENTS AND METHODS

Using antibodies directed against vascular remodeling markers known to be abnormally expressed in plexiform lesions of idiopathic pulmonary hypertension, we performed the first detailed immunohistochemical analysis of the lungs in a patient with PCH. -

RESULTS

As in plexiform lesions, the PCH lesions have increased expression of markers associated with cellular proliferation and angiogenesis such as vascular endothelial growth factor and MiB-1. In contrast to plexiform lesions, the PCH lesions retain markers of cell growth suppression such as peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and caveolin-1.

ANSWER TO QUESTION

This study suggests that the aberrant endothelial cells that lead to the characteristic lesions of PCH and idiopathic pulmonary hypertension are distinct.

Differential expression of ABH histo-blood group antigens and LAMPs in infantile hemangioma

Although infantile hemangioma (IH) are the most common tumors of infancy, the mechanism of their proliferation and involution remains vague. Proliferation, differentiation and death of endothelial cells are the basic processes involved in their pathobiology. Here we hypothesize that the glycoconjugates ABH histo-blood group antigens (HBGA) and lysosome-associated membrane proteins (LAMPs) might be implied in both the differentiation and death of endothelial cells during vascular remodeling in IH. Proliferating and involuting IH were examined immunohistochemically for HGBA and LAMP expression together with vWF and CD31. Proliferative and apoptotic indices were determined. LAMPs were found in immature endothelium of proliferating IH. In involution an increased number of immunopositive cells stained with higher intensity was detected. The enhanced expression might be associated with augmented autophagy required for tissue remodeling during tumor involution. HBGA presented an opposite pattern of expression--they stained intensely the endothelium of mature capillaries, while the immature ones were positive for vWF. The presence of HBGA in endothelial cells of IH may be related to the differentiation process only, as well as to endothelial adhesion and angiogenesis. Novel evidence for differential expression of HBGA and LAMPs in proliferative and involutive phases of IH is presented.

The HIF-2alpha/VEGF pathway activation in cutaneous capillary haemangiomas

AIM

To investigate the pathogenesis of capillary haemangiomas, a common form of vascular malformation.

METHODS

Twenty-five cutaneous capillary haemangiomas, excised from patients under 14 years of age, were studied immunohistochemically for endothelial cells, the angiogenic factors thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF), the proliferation index Ki-67, and the hypoxia inducible factors-1alpha (HIF-1alpha) and -2alpha (HIF-2alpha).

RESULTS

Endothelial-lined channels reacted strongly with CD31 in all cases, clearly definining capillary spaces. Between 5 and 20% of the endothelial cells were Ki-67 positive, indicating an intense proliferative activity; more importantly, they consistently expressed VEGF and HIF-2alpha, and in many cases TP, but failed to react with HIF-1alpha.

CONCLUSION

It is suggested that the activation of the HIF-2alpha pathway and the consequent overexpression of VEGF by the endothelial cells are involved in the pathogenesis of cutaneous capillary haemangiomas.

Capillary hemangioma of the central nervous system: a comparative study with lobular capillary hemangioma of the skin

Capillary hemangiomas have rarely been reported to develop in the brain or spinal cord. Here we report the histological and immunohistochemical features of ten cases of central nervous system capillary hemangiomas (CNSCH) and compare these to those of lobular capillary hemangioma (LCH) of the skin. CNSCH showed a lobular architecture with lobules that were separated by fibrous tissue septa in six cases. The lobules were composed of numerous, tightly packed, capillary-sized vessels. A highly cellular area was seen in six cases. A blood-filled cavernous space and fibroendothelial papillae that mimicked papillary endothelial hyperplasia were seen in four cases. Stromal edema was observed in nine cases. These features were not statistically different from those of LCH of the skin, although the highly cellular area was more prominent and more frequent in cases of CNSCH. Immunohistochemical studies demonstrated no positive staining of endothelial cells within either lesion for erythrocyte-type glucose transporter protein, which is a selective marker for capillary hemangioma of infancy. Vascular endothelial growth factor immunostaining demonstrated positive cells in the solid or immature-appearing areas without vessel lumen formation in both lesions. Some of the endothelial cells and stromal cells were positive for glucocorticoid receptor immunostaining. The MIB-1 index of CNSCH was variable (mean 5.6%) and the apoptotic index of CNSCH was significantly lower than that of LCH of the skin. CNSCH are benign lesions with histological and immunohistochemical features similar to those of LCH of the skin.

Pulmonary Capillary Hemangiomatosis With Atypical Endotheliomatosis *

We report here our experience in achieving remission in a 20-year-old man with pulmonary capillary hemangiomatosis (PCH) with atypical endotheliomatosis following therapy with doxycycline. PCH is a rare disorder characterized by proliferating capillaries that invade the pulmonary interstitium and alveolar septae, and occlude the pulmonary vasculature. The patient's symptoms, lung function, and radiographic findings had worsened despite treatment with both prednisone and alpha-interferon. He was considered to be a candidate for transplantation. Given the elevated levels of basic fibroblast growth factor (bFGF) in urine and the capillary proliferation noted on biopsy specimens, we elected to treat the patient with doxycycline, a matrix metalloproteinase and angiogenesis inhibitor. Following several weeks of therapy, a gradual resolution of symptoms was noted, with normalization of pulmonary function test results and urine bFGF levels. After 18 months of therapy, the patient remains in complete remission.

[The expression of EST and ER in hemangioma with its clinical value]

OBJECTIVE

To study the relationship between estrogen and the development of hemangioma.

METHODS

The expression of EST and ER in samples from the thirty-eight cases of hemangioma and six cases of normal control group was examined with the immunohistochemical steptavidin peroxidase conjugated method (SP method).

RESULTS

The EST in capillary hemangioma expressed significantly higher than in the cavernous hemangioma, the racemose hemangioma or the control group. Although the EST in cavernous hemangioma and racemose hemangioma also expressed higher than in the control, there are no statistical differences among them. The ER only expressed in some cases in the capillary hemangioma group. No sexual difference was shown in the expressions of the EST and the ER.

CONCLUSION

This study shows that there may be a relationship existed between the estrogen and the capillary hemangioma. It may indicate that some capillary hemangioma may be possibly treated by the drugs.

Ovarian capillary hemangioma and stromal luteinization: a case study with hormonal receptor evaluation

BACKGROUND

Ovarian hemangiomas are rare tumors, most of them asymptomatic, and of the cavernous type. Six of the reported cases were accompanied by stromal luteinization. There is a debate whether these luteinized cells promote the growth of the vascular lesion or just represent a stromal reaction.

CASE

A 71-year-old female was incidentally found to have a small capillary hemangioma in her left ovary, surrounded by a rim of luteinized stromal cells. Immunohistochemical investigation revealed the presence of estrogen and progesterone receptors in the endothelial cells of the lesion.

CONCLUSION

Our histological and immunohistochemical findings, as well as data from the literature, support the view that at least some vascular lesions may result from hormonal stimulation.

Proliferation and apoptosis within the oral mucosa "hemangiomas"

In the study the expression of Ki-67, p53, bcl-2 and apoptotic index in ten cases of lobular capillary hemangioma (LCH), ten of capillary hemangioma (CH), and five of epithelioid hemangioma (EH) was examined. The expression of Ki-67, p53 and bcl-2 did not differ significantly between each group of lesions. Instead, significant differences in apoptotic index between LCH and CH were found. The expression of bcl-2 was positively correlated with that of Ki-67 in LCH and CH group, but negatively correlated in the EH group. Our results confirm that LCH, EH and CH, which are histologically similar, are different in terms of proliferation/apoptosis balance. This reflects their different biology, and presumably pathogenesis.

In vitro characteristics of neonatal hemangioma endothelial cells: similarities and differences between normal neonatal and fetal endothelial cells

BACKGROUND

Increased angiogenesis and eventual involution are major characteristics of neonatal hemangiomas. The mechanism to explain this transition is not completely understood.

METHODS

To determine the nature of these changes, endothelial cells were isolated from eight hemangiomas and the growth characteristics and morphology of these cells were compared to cells isolated from normal fetal and neonatal skin. Three cells lines were further characterized by analyzing protein expression with immunohistochemistry and FACS analysis.

RESULTS

Hemangioma endothelial cells converted to a spindle-shaped morphology similar to that of fetal endothelial cells whereas neonatal endothelial cells maintained their characteristic epithelioid morphology. While neonatal, hemangioma and fetal endothelial cells continued to express platelet-endothelial cell adhesion molecule-1 (PECAM-1) and von Willebrand factor (vWf), hemangioma and fetal cells expressed both proteins at a lower level and in a distribution distinct from normal neonatal endothelial cells. Neonatal endothelial cells continued to express epithelial specific Type IV collagen, while hemangioma and fetal endothelial cells produced interstitial Type I collagen.

CONCLUSIONS

Both cell morphology and protein expression of neonatal hemangioma endothelial cells were more characteristic of embryonic microvascular endothelial cells than that of postembryonic cells demonstrating a similarity in these two cell types and suggesting a dysfunction in the normal growth and maturation of endothelial cells in this tumor.

Apoptosis and expression of Bax/Bcl-2 proteins in pyogenic granuloma: a comparative study with granulation tissue and capillary hemangioma

BACKGROUND

Pyogenic granuloma (PG) has been regarded as a florid expression of granulation tissue (GT) proliferation and shows distinct biological behavior compared to conventional GT. PG has not been examined from a standpoint of apoptosis.

METHODS

PG (15 cases), GT (14 cases) and capillary hemangioma (CH, 8 cases) were compared using in situ 3'-tailing reaction (ISTR), a histochemical method for identifying apoptotic cells, and immunohistochemistry for Ki-67, Bcl-2 and Bax proteins, in order to clarify and involvement of apoptosis in the difference of biological characteristics between PG and GT.

RESULTS

PG showed significantly lower ISTR-labeling indices than GT and CH and more frequent Bcl-2/Bax expression than GT, whereas Ki-67-labeling indices were variable from case to case and did not show any significant differences among any groups.

CONCLUSIONS

It is consequently suggested that the low apoptotic rate in PG is closely related to its characteristic rapid growth and is regulated by Bcl-2 family proteins.

Villous capillary lesions of the placenta: distinctions between chorangioma, chorangiomatosis, and chorangiosis

Chorangioma (CA), chorangiosis (CH), and chorangiomatosis (CM) are incompletely understood and overlapping villous capillary (VC) lesions believed by some to be related to hypoxia. In this study, we reviewed all cases of CA (n = 36, 0.51%) and CM (n = 39, 0.55%) diagnosed in 7,062 placentas examined at our institution between 1990 and 1999. CH was evaluated in a subsample of 689 cases (n = 46, 6.67%). Controls were derived from cases in the subsample (n = 639) without any VC lesions. Most CA were incidental findings measuring less than 0.5 cm. Nodular and multinodular morphologic variants were otherwise similar. CA were most frequently located under the chorionic plate and at the placental margins and occasionally showed nonspecific trophoblast hyperplasia (Ki-67-positive) similar to that seen in partial moles. CA and CM shared associations with preeclampia, multiple gestation, and premature delivery at 32 to 26 weeks and had a significant co-occurrence rate. Cases of CM were separated into focal, segmental, and diffuse multifocal subgroups. Diffuse multifocal CM (n = 16) showed associations with extreme prematurity (<32 weeks), congenital malformations, IUGR, delayed villous maturation, avascular villi, and placentomegaly, which were not seen in the other 2 localized subgroups. CH lacked the associations noted for CA and CM, was not increased in placentas with CA or CM, and was most frequent at greater than 37 weeks. CH was positively associated with maternal diabetes, placentomegaly, delayed villous maturation, and chronic villitis. Finally, CH lacked the continuous perivascular layer of muscle-specific actin (MSA)-positive pericytes and the multifibrillar lattice-like reticulin pattern seen in both CA and CM. In conclusion, CA and localized CM are clinically and morphologically similar lesions distinct from CH. Diffuse multifocal CM is morphologically similar to CA and localized CM, but has a distinct clinicopathologic profile.

KIT expression in angiosarcomas and fetal endothelial cells: lack of mutations of exon 11 and exon 17 of C-kit

C-kit proto-oncogene product (KIT, CD117) is a tyrosine kinase growth factor receptor for stem cell factor. This receptor is important for the development and maintenance of hematopoietic stem cells, mast cells, germ cells, melanocytes, and interstitial cells of Cajal and is constitutively expressed in them. Among mesenchymal tumors, KIT seems to be specific for the gastrointestinal stromal tumors, which consistently express this protein. Activating mutations in the tyrosine kinase or juxtamembrane domains of c-kit gene have been found in mastocytoma, seminoma, and gastrointestinal stromal tumors. Following up our initial observation of KIT expression in one angiosarcoma, we examined 50 angiosarcomas, 13 Kaposi sarcomas, 10 epithelioid hemangioendotheliomas, and 31 hemangiomas of different types for KIT expression using a polyclonal antiserum specific to KIT. Adult and fetal tissues and neovascular endothelia in 20 carcinomas were studied for comparison. More than half (56%) of the angiosarcomas representing different clinicopathologic and histologic subtypes and 2 of 13 Kaposi sarcoma were KIT positive. All epithelioid hemangioendotheliomas and hemangiomas were negative, with the exception of two infantile hemangiomas that showed KIT reactivity. The fetal capillary endothelia of lungs, placenta, and soft tissues were also KIT positive, although in soft tissues and placenta, KIT positivity was more prominent in the first trimester. However, endothelia of adult vessels and neovascular capillaries of carcinomas were negative. None of the four KIT-positive angiosarcomas and one KIT-positive Kaposi sarcomas that were studied showed mutations in the juxtamembrane or tyrosine kinase domains of the c-kit gene. These results indicate that KIT expression occurs in a subset of angiosarcomas, and the expression probably represents oncofetal expression (i.e., reversion of the tumor cell phenotype to that of fetal endothelial cells that may show KIT expression).

Phenotype of mast cells in the brain tumor. Capillary hemangioblastoma

Mast cells (MC) are heterogenous cell population. In normal human brain they are not numerous. Increases in number of mast cells within CNS occur in certain disease states including neoplasms. In capillary hemangioblastoma several authors reported mast cells as a fourth cell type of the tumor. The aim of the present study was to examine phenotype and distribution of MC in cerebellar capillary hemangioblastoma by means of specific immunological markers. Study was performed on the tumor of ten affected individuals. Tumor specimens of seven cases were fixed in formalin and embedded in paraffin wax. Additional three tumours were fresh-frozen samples. Mast cells were identified with two monoclonal antibodies generated against tryptase and chymase. In all capillary hemangioblastomas mast cells were numerous exclusively in the tumor mass and only occasionally found in adjacent or far from the tumor located areas of the cerebellum. The cells contained tryptase and chymase. At periphery of hemangioblastomas some mast cells underwent degeneration and calcification. Our results confirm previous observations that mast cells are numerous in the capillary hemangioblastoma and show that most of these cells are tryptase/chymase phenotype (MCTC).

VHL gene deletion and enhanced VEGF gene expression detected in the stromal cells of retinal angioma

OBJECTIVE

Retinal angioma frequently occurs in von Hippel-Lindau (VHL) disease. However, VHL gene alterations have not been documented in retinal angiomas.

METHODS

Using tissue microdissection and polymerase chain reaction amplification, we have analyzed 7 retinal angiomas associated with VHL disease for loss of heterozygosity of the VHL gene. In addition, vascular endothelial growth factor expression was evaluated in these tumors by immunohistochemistry and in situ hybridization.

RESULTS

All 6 informative retinal angiomas showed loss of heterozygosity of the VHL gene. Loss of heterozygosity was detected in vacuolated "stromal" cells, but not in vascular cells or reactive glial tissue. Vascular endothelial growth factor protein and messenger RNA were also present in vacuolated "stromal" cells.

CONCLUSIONS

These findings suggest that vacuolated "stromal" cells represent the true neoplastic component in retinal angioma. These cells express vascular endothelial growth factor and therefore may be responsible for abundant neovascularization of retinal angioma.

Progressive growth of infantile cutaneous hemangiomas is directly correlated with hyperplasia and angiogenesis of adjacent epidermis and inversely correlated with expression of the endogenous angiogenesis inhibitor, IFN-beta

Cutaneous infantile hemangioma progresses through proliferation and involution phases. Since treatment with interferon, a negative regulator of angiogenesis, accelerates the involution phase, we hypothesized that cutaneous infantile hemangioma is associated with an imbalance between endogenous positive and negative regulators of angiogenesis. We examined 30 specimens of cutaneous hemangioma [proliferative phase (n=15), involuting phase (n=8), and involuted phase (n=7)] and control human skin (n=17), fixed in formalin and embedded in paraffin. Routine histology, immunohistochemistry, and an mRNA in situ hybridization technique were used to measure expression of the positive angiogenic molecules basic fibroblast growth factor (bFGF) and vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), and an endogenous inhibitor of angiogenesis, interferon-beta (IFN-beta). Proliferative phase hemangiomas expressed high levels of bFGF and VEGF/VPF but not IFN-beta (mRNA and protein). The epidermis directly overlying proliferating hemangiomas was hyperplastic, contained numerous dividing cells, and expressed bFGF and VEGF/VPF but not IFN-beta. Epidermis from normal individuals and epidermis directly overlying involuted tumors or at sites distant to the proliferating hemangioma was not hyperplastic and expressed normal levels of bFGF, VEGF/VPF, and IFN-beta. These data suggest that the proliferation of cutaneous hemangiomas and adjacent epidermis is associated with an imbalance between positive and negative angiogenic factors expressed by the neoplasm and adjacent normal tissue.

ICAM-3 and E-selectin endothelial cell expression differentiate two phases of angiogenesis in infantile hemangiomas

Cellular adhesion molecules are newly identified mediators of angiogenesis. Infantile hemangiomas, characterized in the early stages by a proliferation of poorly differentiated vessels followed in the late stages by a vascular differentiation and regression of the tumor, represent an interesting model to study angiogenesis. We studied by immunohistochemistry the distribution of HLA-DR and three adhesion molecules ICAM-3, E-selectin and VCAM-1 on endothelial cells in different stages of vessel differentiation in infantile hemangiomas. We found high levels of ICAM-3 expression on proliferating vessels, while its expression was low or undetectable on well differentiated vessels. A different set of E-selectin antibodies showed a more heterogenous pattern of distribution and VCAM-1 antigens were found in both proliferating and differentiated vessels. HLA-DR expression on endothelial cells was inversely correlated to the vascular differentiation. Our results are consistent with the hypothesis that ICAM-3 plays a role in the early stages of vessel formation. Our results also suggest that variation of E-selectin and HLA-DR expression may be related either to vessel differentiation or may reflect the acquisition of an activated endothelial cell status.

Intravascular Kaposi's-like spindle cell proliferation of the capsular vessels of follicular-derived thyroid carcinomas

The literature describes a number of vascular alterations in the thyroid gland and its tumors, the majority of which are related to fine-needle aspiration (FNA). These alterations include pseudoangiosarcomatous changes (Masson's lesion), pseudoinvasion in capsular veins, and endothelial proliferations in the needle tract. We present three cases of a unique intravascular endothelial proliferation in the capsular vessels of follicular and/or Hürthle cell thyroid neoplasms (two angioinvasive Hürthle cell carcinomas and one angioinvasive follicular carcinoma), which we think is unrelated to FNA. The lesion consists of spindle cells with plump nuclei, with focal nesting imparting an epithelioid pattern to the lesion. Focally red blood cells percolate between and mix with the spindle cells, recapitulating superficially a Kaposi's like appearance, but we identified no mitotic figures. Only one patient had a preoperative FNA; in that case, the lesions were spatially separate from the needle tract and the usual post-FNA reactive changes. The lesional cells were positive for Factor VIII and CD 31 and negative for cytokeratins and thyroglobulin immunostains. This immunopanel was helpful in distinguishing these lesions from true angioinvasion by thyroid tumor. To date, the etiology of these vascular lesions is unknown, but we postulate that certain follicular-derived thyroid tumors might elaborate angiogenic mediators, which in a cell culture system of follicular thyroid carcinoma can trigger endothelial proliferations.

Juvenile hemangioma of the testis: analysis of expression of angiogenic factors

We present a case of juvenile hemangioma of the testis associated with hemangiomas of the liver and skin. The testicular hemangioma appeared to progress after therapy with interferon alpha-2a (IFN alpha-2a), whereas the liver and skin hemangiomas regressed. Analysis of growth factors responsible for proliferation of hemangioma revealed that the tumor expressed vascular endothelial growth factor but not basic fibroblast growth factor (bFGF), which is reported to be inhibited by IFN alpha-2a. This finding suggests that a possible explanation for the inadequate efficacy of IFN alpha-2a for testicular hemangioma is a lack of bFGF expression.

Proliferation and apoptosis within juvenile capillary hemangiomas

Capillary hemangiomas (CH) are benign vascular neoplasms of childhood that undergo a natural course of postnatal growth followed by spontaneous involution and often complete regression. There are currently no established standards for the identification of the growth phase of CH. We retrospectively examined 24 CH specimens for staining with MIB1, a monoclonal antibody directed at the same proliferation-related antigen as Ki-67, and antibody to bcl-2, a protooncogene product associated with inhibition of cellular apoptosis, and correlated these findings with the growth phase. All lesions demonstrated more positively with MIB1 than with bcl-2, with more prominent staining in interstitial cells and an inverse correlation with increasing age. When calculations were adjusted for vascular lumina predominance, staining similarly decreased but at a later age. Our study supports interstitial cell-predominant proliferation within CH. In addition, bcl-2 expression was demonstrated, also interstitially predominant, and showed a decrease with aging, suggesting that programmed cellular death is involved in the growth regulation of these lesions and that regression is associated with changes in both proliferation and apoptosis. Last, both proliferation and bcl-2 expression showed a marked decrease later in more vascular channel-predominant lesions, possibly suggesting that such lesions undergo longer periods of growth before entering the involutional phase.