A Rapidly Expanding Hemorrhagic BRAF-Mutant Orbital Atypical Glomus Tumor

A healthy 32-year-old woman presented with the acute onset of left sided eye pain, upper eyelid fullness, and binocular diplopia during light weightlifting. Examination elevated intraocular pressure, proptosis, upper eyelid ptosis, and motility deficits. CT demonstrated a well-circumscribed, homogeneous-appearing extraconal mass in the superior left orbit. The patient underwent an urgent orbitotomy with the excision of a hemorrhagic mass. Histopathology showed a glomus tumor with atypical features and hemorrhagic infarction, best classified as having uncertain malignant potential. A B-Raf proto-oncogene V600E mutation was detected with immunohistochemistry, which suggests a more aggressive tumor behavior yet presents an opportunity for targeted primary or adjunctive therapy. This is the first reported case of a B-Raf proto-oncogene-mutant atypical glomus tumor arising in the orbit.

Novel ATG7::RAF1 gene fusion in malignant glomus tumor

Glomus tumors are classified as members of the perivascular myoid family of tumors. Nearly half of these show NOTCH-gene fusions and a smaller subset has BRAF V600E mutations. Here, we report a novel ATG7::RAF1 fusion in malignant glomus tumor occurring in a 40-year-old female which has not been reported in the malignant glomus tumor before. A 40-year-old female presented with a persistent lateral heel pain and an increase in the size of a mass along the lateral ankle for nearly 10 years. Resected specimen showed a well circumscribed lesion composed of spindled and epithelioid cells with moderate nuclear atypia and mitotic figures (7/10 high-power fields) including atypical forms without any necrosis, lymphovascular, or perineural invasion. The tumor was positive for smooth muscle actin, smooth muscle myosin heavy chain, H-caldesmon, collagen type IV, and discovered on gastronintestinal stromal tumors-1 but negative for AE1/3, desmin, S-100, CD34, and CD117. RNA sequencing showed presence of ATG7-RAF1 fusion. This fusion has not been reported in the malignant glomus tumor before. Future studies on larger cohorts are needed to ascertain the biological significance of these tumors with novel gene fusions.

PDGFRB and NOTCH3 Mutations are Detectable in a Wider Range of Pericytic Tumors, Including Myopericytomas, Angioleiomyomas, Glomus Tumors, and Their Combined Tumors

Pericytic tumors are subclassified as myopericytomas, myofibromas, angioleiomyomas, and glomus tumors according to the current World Health Organization classification. These pericytic tumors form a continuous morphologic spectrum, including those with combined morphology. However, to our knowledge, no widely accepted criteria for classifying tumors with combined morphology are available. Recent studies have identified platelet-derived growth factor receptor-beta (PDGFRB) gene mutations in a subset of myofibromas, myopericytomas, and myopericytomatoses but not in angioleiomyomas. NOTCH receptor 3 (NOTCH3) mutations have been reported in a subset of infantile myofibromatosis. To assess their potential role in classifying pericytic tumors, we investigated PDGFRB and NOTCH3 mutations in 41 pericytic tumors of variable morphology, including some combined forms. Our results show these mutations to be present in a variety of pericytic tumors, such as myopericytomas (PDGFRB, 3/11; NOTCH3, 4/11), myopericytomatoses (1/2; 1/2), myofibromas (3/6; 0/6), angioleiomyomas (2/13; 3/13), and glomus tumors (5/9; 1/9). Point mutations were identified in 3 tumors in PDGFRB exon 12 (Y562C, S574F, and G576S), 12 tumors in PDGFRB exon 14 (M655I, H657L, and N666K), and 9 tumors in NOTCH3 exon 25 (A1480S/T, D1481N, G1482S, T1490A, E1491K, G1494S, and V1512A). All PDGFRB mutations and NOTCH3 G1482S, T1490A, and G1494S mutations were classified as "deleterious/damaging" by ≥4 of 6 pathogenicity prediction tools in silico. Five-mutation-positive tumors, including 1 myopericytoma-angioleiomyoma, 2 myopericytomatoses-myofibroma, 1 myofibroma-myopericytoma and 1 angioleiomyoma-myopericytoma, were of combined morphology. Therefore, we found PDGFRB and NOTCH3 mutations to be detectable in a much wider variety of pericytic tumors than previously reported and confirmed myopericytomas, myofibromas, angioleiomyomas, and glomus tumors as members harboring PDGFRB or NOTCH3 mutations. Our results thus suggest that PDGFRB or NOTCH3 mutations are not useful for subclassifying members of the pericytic tumor family.

Translocation (1;5) in a Glomus Tumor

Glomus tumor is a rare perivascular neoplasm that usually occurs in the distal extremities of young adults. Recent molecular studies have identified microRNA 143-NOTCH fusions or NOTCH1-3 rearrangements in benign and malignant glomus tumors. Herein, we describe the cytogenetic and molecular cytogenetic findings of a glomus tumor arising in the left wrist of a 45-year-old man. Physical examination showed a 1.3-cm, blue-red, tender nodule. Magnetic resonance imaging demonstrated a subcutaneous, well-circumscribed mass with low signal intensity on T1-weighted sequences and high signal intensity on T2-weighted sequences. Contrast-enhanced fat-suppressed T1-weighted sequences showed a homogeneous, strong enhancement. A marginal excision was performed and histopathological examination confirmed the diagnosis of a glomus tumor. Cytogenetic and spectral karyotypic analyses showed a novel rearrangement involving chromosome bands 1p13 and 5q32. There has been no evidence of local recurrence four months after surgery. To the best of our knowledge, this is the first case of sporadic glomus tumor with t(1;5).

Features of gastric glomus tumor: a clinicopathologic, immunohistochemical and molecular retrospective study

Glomus tumor (GT) of the stomach is a rare mesenchymal tumor. There have been few detailed studies on these tumors. A total of 1894 cases of resected gastric mesenchymal tumors were collected and eleven confirmed gastric GTs were studied. The clinical, pathological, immunohistochemical, ultrastructural and molecular characteristics of the tumors were analyzed through a retrospective study. Histologically, most tumors had gastric smooth muscle immediately adjacent and surrounding the tumor. Tumor cells around blood vessels were small, uniform, and round. Foci of hyaline and myxoid changes were observed. Prominent clear cell features were observed in two tumors. Positive expression of α-smooth muscle actin (α-SMA), laminin, collagen type IV, and vimentin was detected by immunohistochemical analysis in all patients. However, in clear cell areas the expression of α-SMA, laminin, and type IV collagen were mild, while Syn was positive. Moreover, myofibrils and neuroendocrine granules were also present in the cytoplasm of these cells. No C-kit or PDGFR-α genetic mutations were detected in all patients. To conclude, Our results show that GTs in the stomach are histologically and immunophenotypically fully comparable with the glomus tumors of peripheral soft tissues. Neuroendocrine granules and neuroendocrine differentiation were identified in some of the gastric GT cells. Thus, a novel subtype of gastric glomus tumor expressing neuroendocrine cell markers may exist.

Novel MIR143-NOTCH fusions in benign and malignant glomus tumors

Glomus tumors (GT) have been classified among tumors of perivascular smooth muscle differentiation, together with myopericytoma, myofibroma/tosis, and angioleiomyoma, based on their morphologic overlap. However, no molecular studies have been carried out to date to investigate their genetic phenotype and to confirm their shared pathogenesis. RNA sequencing was performed in three index cases (GT1, malignant GT; GT2, benign GT and M1, multifocal myopericytoma), followed by FusionSeq data analysis, a modular computational tool developed to discover gene fusions from paired-end RNA-seq data. A gene fusion involving MIR143 in band 5q32 was identified in both GTs with either NOTCH2 in 1p13 in GT1 or NOTCH1 in 9q34 in GT2, but none in M1. After being validated by FISH and RT-PCR, these abnormalities were screened on 33 GTs, 6 myopericytomas, 9 myofibroma/toses, 18 angioleiomyomas and in a control group of 5 sino-nasal hemangiopericytomas. Overall NOTCH2 gene rearrangements were identified in 52% of GT, including all malignant cases and one NF1-related GT. No additional cases showed NOTCH1 rearrangement. As NOTCH3 shares similar functions with NOTCH2 in regulating vascular smooth muscle development, the study group was also investigated for abnormalities in this gene by FISH. Indeed, NOTCH3 rearrangements were identified in 9% of GTs, all present in benign soft tissue GT, one case being fused to MIR143. Only 1/18 angioleiomyomas showed NOTCH2 gene rearrangement, while all the myopericytomas and myofibroma/toses were negative. In summary, we describe novel NOTCH1-3 rearrangements in benign and malignant, visceral, and soft tissue GTs.

Somatic uniparental isodisomy explains multifocality of glomuvenous malformations

Inherited vascular malformations are commonly autosomal dominantly inherited with high, but incomplete, penetrance; they often present as multiple lesions. We hypothesized that Knudson's two-hit model could explain this multifocality and partial penetrance. We performed a systematic analysis of inherited glomuvenous malformations (GVMs) by using multiple approaches, including a sensitive allele-specific pairwise SNP-chip method. Overall, we identified 16 somatic mutations, most of which were not intragenic but were cases of acquired uniparental isodisomy (aUPID) involving chromosome 1p. The breakpoint of each aUPID is located in an A- and T-rich, high-DNA-flexibility region (1p13.1-1p12). This region corresponds to a possible new fragile site. Occurrences of these mutations render the inherited glomulin variant in 1p22.1 homozygous in the affected tissues without loss of genetic material. This finding demonstrates that a double hit is needed to trigger formation of a GVM. It also suggests that somatic UPID, only detectable by sensitive pairwise analysis in heterogeneous tissues, might be a common phenomenon in human cells. Thus, aUPID might play a role in the pathogenesis of various nonmalignant disorders and might explain local impaired function and/or clinical variability. Furthermore, these data suggest that pairwise analysis of blood and tissue, even on heterogeneous tissue, can be used for localizing double-hit mutations in disease-causing genes.

Multiple disseminated glomuvenous malformations: do we know enough?

Multiple glomuvenous malformations (GVMs), also known as glomangiomas, are uncommon entities with histological features of both glomus cells proliferation and venous malformation. A 14-year-old boy was admitted to our clinic with multiple dermal blue nodules, disseminated in different segments of the body. The patient's family history was positive for similar lesions; his mother and maternal grandmother had some asymptomatic blue nodules on their body. Histological examination showed a tumor composed of multiple caveronous vessels surrounded by glomus cells, positive for alpha smooth muscle actin, HHF35 (pan-actin), and h-caldesmon. This is a case of multiple GVMs, a rare disease caused by mutations in glomulin gene, with an autosomal dominant pattern of inheritance. The clinical and histopathological features are briefly discussed.

Glomuvenous Malformations (Familial generalized multiple glomangiomas)

A 15-year-old boy with a diagnosis of generalized multiple glomangiomas was referred for evaluation and treatment of enlarging and increasingly painful lesions on his right ankle. The patient underwent a series of two treatments with long-pulsed KTP 1064 nm laser that resulted in substantial improvement in appearance and decreased pain. Generalized glomuvenous malformations, or multiple glomangiomas, are the less common presentation of proliferation of glomus cells and may have extracutaneous involvement. Whereas surgical management is often employed and definitive for solitary lesions, interventions such as laser therapy, may be beneficial for improvement of functional impairment and cosmesis as was observed in our patient.

Multiple glomus tumors and segmental neurofibromatosis: there are no coincidences

Segmental neurofibromatosis is a rare subtype of neurofibromatosis type 1 (NF1). Glomus tumors are uncommon benign tumors. The authors report the association between these two rare conditions, not yet reported.

Type 2 segmental glomangiomas

Glomangiomas of the skin, currently named glomuvenous malformations (GVMs), are benign vascular lesions composed of thin-walled distorted blood vessels, surrounded by variable rows of glomus cells. These cells resemble the modified smooth muscle cells of the normal glomus body. Glomuvenous malformations occur after both alleles of the gene encoding for glomulin, a molecule involved in smooth muscle cell differentiation, are hit by a loss-of-function mutation. Multiple GVMs are rare and often congenital, but they may also appear later in life. In this report we describe a 39-year-old man who developed unilateral segmental GVMs on his trunk in early childhood, with the histological features of glomangiomas. As several satellite lesions emerged at distant skin sites later in life, our case probably represents type 2 segmental GVMs, caused by localized loss of heterozygosity in an individual carrying a heterozygous germline mutation in the glomulin gene.

Glomus tumors in neurofibromatosis type 1: genetic, functional, and clinical evidence of a novel association

Neurofibromatosis type 1 (NF1) is a common disorder that arises secondary to mutations in the tumor suppressor gene NF1. Glomus tumors are small, benign but painful tumors that originate from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. We report 11 individuals with NF1 who harbored 20 glomus tumors of the fingers and 1 in the toe; 5 individuals had multiple glomus tumors. We hypothesized that biallelic inactivation of NF1 underlies the pathogenesis of these tumors. In 12 NF1-associated glomus tumors, we used cell culture and laser capture microdissection to isolate DNA. We also analyzed two sporadic (not NF1-associated) glomus tumors. Genetic analysis showed germ line and somatic NF1 mutations in seven tumors. RAS mitogen-activated protein kinase hyperactivation was observed in cultured NF1(-/-) glomus cells, reflecting a lack of inhibition of the pathway by functional neurofibromin, the protein product of NF1. No abnormalities in NF1 or RAS mitogen-activated protein kinase activation were found in sporadic glomus tumors. By comparative genomic hybridization, we observed amplification of the 3'-end of CRTAC1 and a deletion of the 5'-end of WASF1 in two NF1-associated glomus tumors. For the first time, we show that loss of neurofibromin function is crucial in the pathogenesis of glomus tumors in NF1. Glomus tumors of the fingers or toes should be considered as part of the tumor spectrum of NF1.

Genetic analysis of a family with hereditary glomuvenous malformations

Glomuvenous malformations (MIM 138000) are rare vascular malformations consisting of glomus cells, and in affected individuals, lesions may appear in any number anywhere on the body. We analysed the DNA of one family with hereditary glomuvenous malformations and identified the mutation causing the disease in the glomulin gene on chromosome 1 p22. The deletion started at base pair 157: 157delAAGAA, which is a deletion of five base pairs. This mutation has been found in Europe, the USA and Australia, suggesting a founder effect with common ancestry. Thus far, no second-hit mutation for the 157delAAGAA mutation has been identified.

Mutation analysis in Irish families with glomuvenous malformations

BACKGROUND

Glomuvenous malformations (GVMs) are rare bluish lesions that can affect the skin and mucosal surfaces. They represent defects in vasculogenesis. Lesions can occur sporadically or in an autosomal dominant mode of inheritance. Recent studies have shown that mutations in the glomulin gene (GLMN) on chromosome 1p21-22 are responsible for familial GVMs.

OBJECTIVES

To search for mutations in GLMN in Irish families with GVMs.

METHODS

We identified four Irish families with GVMs and confirmed linkage to chromosome 1p21-22 in these cases. We sequenced the glomulin gene in all affected and unaffected members of the families. Results Linkage analysis showed that affected individuals from the families shared a common haplotype. Mutation analysis revealed a delAAGAA mutation in exon 3 of the glomulin gene in all four families with GVMs.

CONCLUSIONS

We confirm that mutations in the glomulin gene are responsible for GVMs and suggest a founder Irish mutation in the glomulin gene in four Irish families.

Congenital Plaque-Type Glomuvenous Malformations Presenting in Childhood

BACKGROUND

Glomuvenous malformations (GVMs) are now considered a separate entity from venous malformations. The rarest type of GVM is the generalized congenital plaque-type GVM.

OBSERVATIONS

We present 10 new cases of congenital plaque-type GVM and describe their clinical progression and treatment. Mutations in the glomulin gene were found in those patients who participated in the genetic study.

CONCLUSIONS

Congenital plaque-type GVMs are unique in their congenital nature, extensive distribution, difficult to diagnose and treat, and progressive involvement after birth. Most cases are familial, yet affected relatives usually have only minor lesions. The lesions of congenital plaque-type GVM are severe, visible at birth, and usually mistaken for extensive venous malformations. Vascular malformations are divided by hemodynamic type into slow-flow and fast-flow lesions. Slow-flow lesions are subcategorized as capillary, lymphatic, and venous.(1) Capillary malformations are flat, sharply demarcated, red-pink vascular stains of the skin commonly referred to as port-wine stains. These persist throughout life and are characterized histologically by dilated capillaries within the dermis. They slowly increase in size with age. Lymphatic malformations are spongelike collections of abnormal channels and spaces that contain clear lymphatic fluid, causing an excess of fluid to accumulate and dilate the lymphatic channels. This results in swelling of the affected area and, if extensive, can cause enlargement of soft tissues and bones.

Four common glomulin mutations cause two thirds of glomuvenous malformations ("familial glomangiomas"): evidence for a founder effect

BACKGROUND

Glomuvenous malformation (GVM) ("familial glomangioma") is a localised cutaneous vascular lesion histologically characterised by abnormal smooth muscle-like "glomus cells" in the walls of distended endothelium lined channels. Inheritable GVM has been linked to chromosome 1p21-22 and is caused by truncating mutations in glomulin. A double hit mutation was identified in one lesion. This finding suggests that GVM results from complete localised loss of function and explains the paradominant mode of inheritance.

OBJECTIVE

To report on the identification of a mutation in glomulin in 23 additional families with GVM.

RESULTS

Three mutations are new; the others have been described previously. Among the 17 different inherited mutations in glomulin known up to now in 43 families, the 157delAAGAA mutation is the most common and was present in 21 families (48.8%). Mutation 108C-->A was found in five families (11.8%), and the mutations 554delA+556delCCT and 1179delCAA were present together in two families (4.7% each). Polymorphic markers suggested a founder effect for all four mutations.

CONCLUSIONS

Screening for these mutations should lead to a genetic diagnosis in about 70% of patients with inherited GVM. So far, a mutation in glomulin has been found in all GVM families tested, thus demonstrating locus homogeneity.

[Familial glomus tumor encountered in the same finger and localization in four family members]

A 35-year-old man was referred to our clinic by a neurosurgeon for hypersensitivity and severe pain in his right middle finger. History showed that the symptoms had been present for three years and he had made several attempts to seek medical attention. A sensitive, very painful mass was palpated under the eponychium of his right middle finger. The tumor was surgically removed and histological examination confirmed the clinical diagnosis of a glomus tumor. Inquiry into the family history revealed that the same problem existed in the same localization with similar complaints in the father and two daughters. Both the records of the father's operation 10 years before and clinical-radiological findings of the daughters were consistent with a familial entity. In the presence of hypersensitivity and pain in the finger, family members should be inquired and a diagnosis of familial glomus tumor should be considered.

Glomuvenous Malformation (Glomangioma) and Venous Malformation

OBJECTIVES

To develop clinical criteria that permit clinical distinction between inherited glomuvenous malformation (GVM), known as glomangioma, and inherited cutaneomucosal venous malformation and to test these criteria on sporadic lesions.

DESIGN

Clinical data were compiled for 1685 patients with inherited or sporadic cutaneous venous anomalies. Based on a cohort of patients with a mutation in the TIE2 or glomulin gene or a histologic diagnosis, we defined clinical criteria for inherited GVM and cutaneomucosal venous malformation. We then applied these criteria to sporadic cases in a blinded manner and genetically or histologically confirmed this clinical diagnosis whenever possible.

RESULTS

Glomuvenous malformations accounted for 5.1% of venous anomalies and were frequently inherited (63.8%), whereas venous malformations were rarely familial (1.2%). Glomuvenous malformations were nodular and scattered, or plaque-like and segmental, with color varying from pink to purplish dark blue, whereas most venous malformations (VMs) were soft, blue, and often localized vascular lesions. Glomuvenous malformations were mainly located on the extremities and involved skin and subcutis, whereas VMs commonly affected muscles and joints (P<.001). Glomuvenous malformations had a distinct raised, often hyperkeratotic cobblestone-like appearance and could not be completely emptied by compression, unlike VMs. Glomuvenous malformations were painful by compression, whereas VMs were painful on awakening, after activity, or with hormonal changes. Elastic compressive garments aggravated pain in GVMs, in contrast to VMs.

CONCLUSIONS

This large series of patients with superficial venous anomalies established clinical features that distinguish VMs and GVMs. This differential diagnosis is essential, as the outcome and the treatment for GVMs differ.

Complete pain relief following treatment of a glomangiomyoma with the pulsed dye laser

Hereditary multiple glomus tumours constitute an autosomal dominant skin disease which is known to demonstrate cutaneous mosaicism typified by type 1 and 2 segmental arrangements. We report a patient with type 2 segmental multiple glomangiomyomas who was disturbed by the pain of her lesions. A symptomatic lesion was successfully treated with the pulsed dye laser and to date there has been no recurrence of the pain. Possible explanations for the clinical response are discussed.

18F-DOPA positron emission tomography for the detection of glomus tumours

The purpose of this study was to evaluate (18)F-DOPA whole-body positron emission tomography ((18)F-DOPA PET) as a biochemical imaging approach for the detection of glomus tumours. (18)F-DOPA PET and magnetic resonance imaging (MRI) were performed in ten consecutive patients with proven mutations of the succinate dehydrogenase subunit D ( SDHD) gene predisposing to the development of glomus tumours and other paragangliomas. (18)F-DOPA PET and MRI were performed according to standard protocols. Both methods were assessed under blinded conditions by two experienced specialists in nuclear medicine (PET) and diagnostic radiology (MRI). Afterwards the results were compared. A total of 15 lesions (four solitary and four multifocal tumours, the latter including 11 lesions) were detected by (18)F-DOPA PET. Under blinded conditions, (18)F-DOPA PET and MRI revealed full agreement in seven patients, partial agreement in two and complete disagreement in one. Eleven of the 15 presumed tumours diagnosed by (18)F-DOPA PET were confirmed by MRI. The correlation of (18)F-DOPA PET and MRI confirmed three further lesions previously only detected by PET. All of them were smaller than 1 cm and had the signal characteristics of lymph nodes. For one small lesion diagnosed by PET, no morphological MRI correlate could be found even retrospectively. No tumour was detected by MRI that was negative on (18)F-DOPA PET. All tumours diagnosed by MRI showed a hyperintense signal on T2-weighted images and a distinct enhancement of contrast medium on T1-weighted images. The mean tumour size was 1.5+/-0.5 cm. (18)F-DOPA PET seems to be a highly sensitive metabolic imaging procedure for the detection of glomus tumours and may have potential as a screening method for glomus tumours in patients with SDHD gene mutations.

Multiple familial facial glomus: case report and review of the literature

Facial paraganglioma is an extremely rare tumor that originates from abnormal paraganglionic tissue situated in the intrapetrous facial canal. A review of the English-language literature shows that only 8 cases of facial nerve paraganglioma have been published. In each case the facial glomus presented itself sporadically, completely independent of any other form of paraganglioma. This study reports an intrapetrous facial glomus that occurred in a case of multiple paragangliomas with a hereditary pattern. To our knowledge, this is the first report of such a combination.

Familial generalized multiple glomangiomyoma: report of a new family, with immunohistochemical and ultrastructural studies and review of the literature

Glomus tumors are benign lesions which often appear as solitary bluish nodules. They can also be multiple, and can be either acquired or congenital. Histopathologically glomus tumors are classified into three different variants: solid glomus tumor, glomangioma, and glomangiomyoma, which is the least frequent type. We report three instances of familial generalized multiple glomangiomyoma in a woman and her two children. Seven members of the family in two consecutive generations were affected, suggesting autosomal dominant inheritance. We performed a thorough clinical study, complete blood and platelet counts, stool for occult blood, karyotype, abdominal echography (which showed an asymptomatic solitary hepatic vascular lesion in one of the patients), gastrointestinal endoscopy, and skin biopsy with immunohistologic and ultrastructural studies. We believe that the terms glomangioma and glomangiomyoma actually designate the same lesion, with transitional areas from typical glomus cells to well-defined conventional smooth muscle cells. Although complete evaluation should be performed in all patients with multiple glomus tumors in order to detect possible occult systemic lesions, we only recommend treatment for symptomatic lesions. To our knowledge, this is the first report of an instance of familial multiple glomangiomyoma.

Clinical report on the L95P mutation in a Dutch family with paraganglioma

OBJECTIVE

To describe the new L95P mutation of the paraganglioma 1 gene for glomus tumors in a Dutch paraganglioma 1 family with six affected family members and to report the clinical findings and results of treatment in nine glomus tumors with a maximum follow-up of 34 years.

SETTING

Tertiary referral centers.

RESULTS

Mutation analysis of the SDHD gene of paraganglioma 1 showed the L95P mutation in six affected family members and two nonaffected carriers protected from becoming affected by genomic imprinting. In six affected family members, nine glomus tumors (five glomus caroticum tumors, two glomus vagale tumors, and two glomus jugulare tumors) were traced. The ages at presentation varied from 25 to 61 years. In two of six affected family members with a total of four tumors, all the tumors were traced in the extended family study, using magnetic resonance imaging; at that time these tumors were silent. After radiotherapy in one patient at the age of 34 years, a T4 planocellular carcinoma of the tongue occurred within the previous radiation field 27 years later, when the patient was 61 years old. Volume measurements of three untreated glomus tumors (two glomus vagale tumors, one glomus caroticum tumor) during 25 months showed an increase in two tumors (left glomus caroticum, left glomus vagale tumor) and a decrease in one tumor (right glomus vagale tumor). Surgery to remove two bilateral and one unilateral glomus caroticum tumors was successful. A wait-and-see policy is being applied to two glomus vagale tumors.

CONCLUSIONS

In family members of paraganglioma 1 patients, mutation analysis can be used to make an early diagnosis of glomus tumors. Radiotherapy may have induced a carcinoma. Modalities of treatment can include a wait-and-see policy. Long-term follow-up studies on the natural course of glomus tumors are needed to improve decisions about treatment modalities.

Germ-line mutations in nonsyndromic pheochromocytoma

BACKGROUND

The group of susceptibility genes for pheochromocytoma that included the proto-oncogene RET (associated with multiple endocrine neoplasia type 2 [MEN-2]) and the tumor-suppressor gene VHL (associated with von Hippel-Lindau disease) now also encompasses the newly identified genes for succinate dehydrogenase subunit D (SDHD) and succinate dehydrogenase subunit B (SDHB), which predispose carriers to pheochromocytomas and glomus tumors. We used molecular tools to classify a large cohort of patients with pheochromocytoma with respect to the presence or absence of mutations of one of these four genes and to investigate the relevance of genetic analyses to clinical practice.

METHODS

Peripheral blood from unrelated, consenting registry patients with pheochromocytoma was tested for mutations of RET, VHL, SDHD, and SDHB. Clinical data at first presentation and follow-up were evaluated.

RESULTS

Among 271 patients who presented with nonsyndromic pheochromocytoma and without a family history of the disease, 66 (24 percent) were found to have mutations (mean age, 25 years; 32 men and 34 women). Of these 66, 30 had mutations of VHL, 13 of RET, 11 of SDHD, and 12 of SDHB. Younger age, multifocal tumors, and extraadrenal tumors were significantly associated with the presence of a mutation. However, among the 66 patients who were positive for mutations, only 21 had multifocal pheochromocytoma. Twenty-three (35 percent) presented after the age of 30 years, and 17 (8 percent) after the age of 40. Sixty-one (92 percent) of the patients with mutations were identified solely by molecular testing of VHL, RET, SDHD, and SDHB; these patients had no associated signs and symptoms at presentation.

CONCLUSIONS

Almost one fourth of patients with apparently sporadic pheochromocytoma may be carriers of mutations; routine analysis for mutations of RET, VHL, SDHD, and SDHB is indicated to identify pheochromocytoma-associated syndromes that would otherwise be missed.

Mutations in a novel factor, glomulin, are responsible for glomuvenous malformations ("glomangiomas")

Glomuvenous malformations (GVMs) are cutaneous venous lesions characterized by the presence of smooth-muscle--like glomus cells in the media surrounding distended vascular lumens. We have shown that heritable GVMs link to a 4--6-cM region in chromosome 1p21-22. We also identified linkage disequilibrium that allowed a narrowing of this VMGLOM locus to 1.48 Mb. Herein, we report the identification of the mutated gene, glomulin, localized on the basis of the YAC and PAC maps. An incomplete cDNA sequence for glomulin had previously been designated "FAP48," for "FKBP-associated protein of 48 kD." The complete cDNA for glomulin contains an open reading frame of 1,785 nt encoding a predicted protein of 68 kD. The gene consists of 19 exons in which we identified 14 different germline mutations in patients with GVM. In addition, we found a somatic "second hit" mutation in affected tissue of a patient with an inherited genomic deletion. Since all but one of the mutations result in premature stop codons, and since the localized nature of the lesions could be explained by Knudson's two-hit model, GVMs are likely caused by complete loss of function of glomulin. The abnormal phenotype of vascular smooth-muscle cells (VSMCs) in GVMs suggests that glomulin plays an important role in differentiation of these cells--and, thereby, in vascular morphogenesis--especially in cutaneous veins.

Gastrointestinal glomus tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 32 cases

Glomus tumors usually occur in the peripheral soft tissues, but similar tumors have also been reported in the stomach and occasionally in the intestines. However, the relationship of these tumors to peripheral glomus tumors and gastrointestinal stromal tumors has not been fully clarified because previous series of gastrointestinal glomus tumors predate availability of immunohistochemistry. This clinicopathologic study examined 32 gastrointestinal glomus tumors. All but one of the tumors were located in the stomach and the remaining tumor was from the cecum. The tumors occurred with a strong female predominance (23 females and 9 males) and a median age of 55 years (range 19-90 years). The gastric tumors typically presented with gastrointestinal bleeding or ulcer-like symptoms, and 14 tumors had mucosal ulceration. Five tumors were incidental findings. The tumor sizes varied from 1.1 to 7 cm (median 2 cm), and most were located in the antrum. Histologically, the tumors typically had a solid pattern of sharply demarcated, round glomus cells with prominent, mildly dilated pericytoma-like vessels. Vascular invasion and focal atypia were relatively common (seen in 11 and 13 cases, respectively), and low mitotic activity (1-4 per 50 high power fields), was seen in 10 cases. Immunohistochemically, all tumors were positive for alpha-smooth muscle actin and calponin, and nearly all had a net-like pericellular laminin and collagen type IV positivity. All tumors were negative for desmin and S-100 protein. Three tumors had focal synaptophysin positivity, but none was positive for chromogranin. All tumors lacked KIT expression and the GIST-specific mutations in the c-kit gene. Follow-up revealed one patient death of metastatic disease to liver at 50 months; this tumor had 1 mitosis per 50 high power fields, but had spindle cell foci, mild atypia, and vascular invasion. Thirteen patients were well and alive after long-term follow-up. Gastrointestinal glomus tumors occur almost exclusively in the stomach, and they have a good overall prognosis, but a small, unpredictable potential for malignant behavior exists. These tumors are phenotypically similar to peripheral glomus tumors and differ from epithelioid GISTs.

Local and systemic expression of basic fibroblast growth factor in a patient with familial glomangioma

Glomangiomas are rare cutaneous tumours composed of glomus cells, which are modified smooth muscle cells. The aetiology of this condition is thought to involve a mutation in a novel gene acting to regulate angiogenesis. We report a patient from a large family with three generations affected by familial multiple glomangiomas. We hypothesized that the growth factors basic fibroblast growth factor and vascular endothelial growth factor, which stimulate/regulate angiogenesis could be involved in the pathogenesis of these lesions. Therefore, using enzyme-linked immunosorbent assays and immunohistochemistry, respectively, we measured systemic and tissue levels of these growth factors in a patient with familial glomangiomas. In addition, we investigated endothelial mitogenicity of the patient's serum as a functional assay of systemic growth factor activity.

Multiple hereditary glomangiomas: successful treatment with sclerotherapy

Glomangiomas are characterized by cavernous vascular channels surrounded by glomus cells. Multiple glomangiomas, although usually painless, can be a few centimetres in size and appear as blue phlebectatic lesions. Surgical excision of multiple glomangiomas can lead to scarring and recurrences. Laser treatment using vascular lasers and CO2 lasers has been useful in small, superficial lesions. We present the successful sclerotherapy treatment of multiple glomangiomas using sodium tetradecyl sulphate in a 59-year-old man who presented with postoperative recurrence of multiple lesions.

Molecular genetics of vascular malformations

Vascular malformations are localized errors of angiogenic development. Most are cutaneous and are called vascular 'birthmarks'. These anomalies are usually obvious in the newborn, grow commensurately with the child, and gradually expand in adulthood (Mulliken and Glowacki, 1982). Vascular malformations also occur in visceral organs, such as the respiratory and gastrointestinal tract, but are more common in the brain (Mulliken and Young, 1988). These anomalies are composed of tortuous vascular channels of varying size and shape, lined by a continuous endothelium and surrounded by abnormal complement of mural cells. Vascular malformation can be life threatening due to obstruction, bleeding or congestive heart failure. Most anomalies occur sporadically, but there are families exhibiting autosomal dominant inheritance. Genetic studies of such families have resulted in the identification of mutated genes, directly giving proof of their important role in the regulation of angiogenesis.

Facial "glomangiomas": large facial venous malformations with glomus cells

BACKGROUND

"Glomangiomas" are benign cutaneous vascular lesions consisting of convoluted, abnormally formed venous channels lined by cuboidal and oval epithelioid, alpha-actin-positive, glomus cells. Three different clinical variants of glomangioma have been recognized: solitary, multiple, and nodular, or plaquelike. Inheritable forms are common.

OBJECTIVE

We describe in 7 patients (2 of them having a familial glomangiomatosis) the rare facial location of glomangiomas to differentiate this type from common facial venous malformation (VM).

METHODS

We analyzed clinical data (photographs), course, investigations (computed tomographic scans in 4 patients, magnetic resonance imaging in 6, arteriography in 2, direct puncture phlebography in 4, and pathologic examinations in all 7), and outcome with treatment.

RESULTS

Lesions were soft, composed of multiple nodules, confluent and plaquelike, deep blue or blue-to-purple, sometimes sagging, one-sided in a cheek, extending to the lips in 5 patients, to the chin in 4, and to the lower eyelid in 4. They were poorly compressible, a finding different from common facial VMs. In a young man extensive back involvement was associated. Among radiologic investigations, only magnetic resonance imaging after gadolinium enhancement offered some differential features with common VMs. However, histopathologic examination clarified the differential diagnosis: although the large tortuous venous channels were reminiscent of capillary-venous malformation, in many vessels the walls contained one or several rows of glomus cells.

CONCLUSION

Multiple plaquelike facial "glomangiomas" mimic a common venous malformation because of their blue hue. However, with experience, one can clinically recognize them, and their pathologic aspect is distinctive. Management should differ slightly from that for common facial VM because sclerotherapy has proven to be less effective. Therefore surgical treatment is the only helpful therapeutic option.

Additional glomangioma families link to chromosome 1p: no evidence for genetic heterogeneity

Venous malformations are a common abnormality of the vasculature that may occur sporadically or, more rarely, as an autosomal dominant trait. One familial form of venous malformations has previously been linked to chromosome 9p. Mutations in the gene encoding Tie2, an endothelial specific receptor tyrosine kinase, have been identified in four different families. Glomangiomas are a subtype of venous malformations with glomus cell involvement. These cutaneous lesions can be inherited as an autosomal dominant disease with reduced penetrance and variable expressivity. We present evidence of linkage to chromosome 1p21-1p22 using four new glomangioma families, with a combined maximum two-point lod score of 7.32 at marker D1S2804. Markers D1S2129 and D1S2881 define the 24-cM linkage interval determined by recombination within affected individuals. A recent report also showed linkage of the glomangioma locus to chromosome 1p. A total of 9 families now map to this region, suggesting a decreased likelihood of locus heterogenity in familial glomangiomas. Investigation of candidate genes within the interval should provide new insights into lesion formation in inherited venous malformations.

Linkage disequilibrium narrows locus for venous malformation with glomus cells (VMGLOM) to a single 1.48 Mbp YAC

Venous malformations with glomus cells are localised cutaneous lesions of vascular dysmorphogenesis. They are usually sporadic, but sometimes familial. Using five families, we mapped the locus, VMGLOM, to chromosome 1p21-p22. In order to refine this locus, spanning 4-6 Mbp, we then studied seven additional families. They exhibited linkage to VMGLOM and the combined lod score for all 12 families was 18.41 at theta = 0.0 for marker D1S188. We found a distinct haplotype shared by seven families, comprising seven alleles which are rare in the general population (P < 0.01). This indicates that the haplotype is identical by descent in all seven families, and hence the locus can be refined by inferring ancestral crossovers. Using this approach, we position the causative gene between two markers on the same non-chimeric YAC of 1.48 Mbp, a feasible size for positional cloning. As there is no known gene involved in vasculogenesis and/or angiogenesis in this YAC, the identification of the causative gene is likely to reveal a novel regulator or vascular development.

[Carotid body tumors: contribution of the various imaging techniques. A report of six cases]

INTRODUCTION

Carotid body tumors are rare hypervascular lesions arising from neural crest paraganglion cells.

MATERIALS AND METHODS

We retrospectively analyzed the imaging features of six patients with carotid body tumors to precise their imaging characteristics in order to find specific signs and elaborate a strategy for diagnosis.

RESULTS

Imaging features detect the vascular nature of these tumors of the carotid space causing characteristic widening of the carotid bifurcation. Two patients had multiple (two or more) localizations and one had a family history of glomus tumor.

CONCLUSION

MRI with MRA is considered as the gold standard imaging technique for the evaluation of glomus tumors as it allows a multiplanar approach which is important in the preoperative study.

High-resolution physical and transcript map of the locus for venous malformations with glomus cells (VMGLOM) on chromosome 1p21-p22

Vascular anomalies are congenital lesions that usually occur sporadically, but can be inherited. Previously, we have described that venous malformations, localized bluish-purple skin lesions, are caused by an activating mutation in the TIE2/TEK receptor. Moreover, we mapped another locus to chromosome 1p21-p22, for venous malformations with glomus cells (VM-GLOM). Here we report a physical map, based on 18 overlapping YAC clones, spanning this 5-Mb VMGLOM locus, from marker GATA63C06 to D1S2664. In addition, we report a sequence-ready PAC map of 46 clones covering 1.48 Mb within the YAC contig, a region to which we have restricted VMGLOM. We describe 21 new STSs and nine novel CA repeats, seven of which are polymorphic. These data will enable positional cloning of genes for diseases mapped to this locus, including the VMGLOM gene, likely a currently unknown regulator of vasculogenesis and/or angiogenesis.

Multiple familial cutaneous glomangioma: a pedigree of 4 generations and critical analysis of histologic and genetic differences of glomus tumors

BACKGROUND

Glomangiomas are benign tumors arising from neuromyoarterial cells surrounding cutaneous arteriovenous anastomoses that serve as temperature regulators. They exist as solitary or multiple types, occurring sporadically or in a familial pattern, the latter of which is rare.

OBJECTIVE

We describe a 4-generation pedigree of familial cutaneous glomangioma, in addition to the 3 other well-documented pedigrees reported in the literature to date, and we clarify ways in which to distinguish the different types of glomus tumors.

METHODS

Nodular skin lesions of 4 affected family members were analyzed by histologic, immunohistologic, and electron microscopic methods. To elucidate the gene defect in this family, we searched for a linkage to a candidate locus on chromosome 11q23 previously identified in paragangliomas, one form of glomus tumor, in 16 family members of 4 generations by using polymorphic markers.

RESULTS

The diagnosis of disseminated cutaneous glomangiomas was confirmed histologically in 4 family members of 3 different generations. Glomangiomas were transmitted in an autosomal dominant pattern via the paternal line. Genetic linkage analysis of the affected family members excluded linkage to chromosome 11q23.

CONCLUSION

An autosomal dominant pattern of inheritance has been described for glomus tumors of the paraganglioma type originating from the APUD cell system, the underlying genetic defect of which has been mapped to chromosome 11q23. In contrast, we show that the genetic defect in disseminated cutaneous glomus tumors of the glomangioma type deriving from smooth muscle cells or pericytes is not linked to chromosome 11. Thus we suggest that the common term glomus tumor, used for both paragangliomas and glomangiomas in the current literature, is misleading and should be avoided because these tumors have different histologic derivation and genetic origin.

Type 2 segmental manifestation of multiple glomus tumors: A review and reclassification of 5 case reports

BACKGROUND

In various autosomal dominant skin disorders, segmental forms reflecting mosaicism have been reported. Recently, two different types of mosaic manifestation have been delineated. Type 1 reflects heterozygosity for the underlying mutation and shows a degree of severity as observed in the corresponding nonmosaic phenotype. Type 2 originates from loss of heterozygosity, shows an excessively severe involvement and is usually superimposed on the disseminated lesions of the ordinary trait.

OBJECTIVE

We wanted to exemplify further the proposed rule of dichotomy.

METHODS

We have screened the literature on multiple glomus tumors, a trait that follows an autosomal dominant mode of transmission.

RESULTS

We found 5 cases of multiple glomus tumors suggesting a type 2 segmental involvement. In all of these cases, a unilateral band-like or patchy arrangement of excessively pronounced glomus tumors was associated with disseminated lesions corresponding to the ordinary phenotype, and in 3 cases other family members were affected with disseminated glomus tumors. The unilateral agminated lesions were reported to be present in early childhood, whereas the disseminated lesions appeared later.

CONCLUSION

Multiple glomus tumors can be added to the list of autosomal dominant skin disorders that may show a type 2 segmental involvement.

A gene for inherited cutaneous venous anomalies ("glomangiomas") localizes to chromosome 1p21-22

Venous malformations (VMs) are localized defects of vascular morphogenesis. They can occur in every organ system, most commonly in skin and muscle. They can cause pain and bleeding, and in some critical locations they can be life threatening. Usually venous anomalies occur sporadically, but families with dominant inheritance have been identified. Using linkage analysis, we have established in earlier reports that some families with inherited VMs show linkage to chromosome 9p21; the mutation causes ligand-independent activation of an endothelial cell-specific receptor tyrosine kinase, TIE-2. Here we show that VMs with glomus cells (known as "glomangiomas"), inherited as an autosomal dominant trait in five families, are not linked to 9p21 but, instead, link to a new locus, on 1p21-p22, called "VMGLOM" (LOD score 12.70 at recombination fraction.00). We exclude three known positional candidate genes, DR1 (depressor of transcription 1), TGFBR3 (transforming growth factor-beta receptor, type 3), and TFA (tissue factor). We hypothesize that cutaneous venous anomalies (i.e., glomangiomas) are caused by mutations in a novel gene that may act to regulate angiogenesis, in concert with the TIE-2 signaling pathway.

[Sclerosing in multiple familial glomangiomas]

Glomus tumors (glomangiomata) are benign tumors arising from glomus cells. Multiple glomangiomata are less frequent and less painful than the solitary variant, which is usually located subungually. Nonetheless multiple glomangiomata--sometimes being sensitive to pressure and changes in temperature--may cause considerable discomfort. Treatment of multiple glomangiomata is problematic because of the often large number of tumors. Sclerotherapy represents an alternative to surgical and cryosurgical therapy. We report on sclerotherapy in a 35 year old female patient with multiple hereditary glomus tumors.

Hereditary multiple glomangiomas

Hereditary multiple glomangiomas are an interesting rare problem which can either present as multiple painful cutaneous lesions or, rarely, a cosmetic challenge due to site, size or number of lesions. It may also pose a diagnostic dilemma, which can only be settled by biopsy. Malignant change in glomangioma is extremely rare and only a few cases are well documented in literature. A case report of this condition, along with extensive review of the literature, is presented. The prognosis of various forms of glomangiomas and efficacy of diagnostic and therapeutic tools is discussed.

A high-resolution STS, EST, and gene-based physical map of the hereditary paraganglioma region on chromosome 11q23

The genes responsible for hereditary paragangliomas (glomus tumors, MIM No. 168000) have been mapped to two distinct loci on the long arm of chromosome 11. Most of the informative families appear to be linked to the distal locus on chromosome 11q23 (PGL1), which has been previously confined to a 2-cM interval by haplotype analysis in an extended Dutch pedigree. To facilitate the identification of the PGL1 disease gene, we constructed an approximately 4-Mb ordered clone contig map of Sequence tagged sites, expressed sequence tags (ESTs), and known genes that spans the PGL1 critical region on chromosome 11q23. Among 29 new positional candidate ESTs, only two (EST100999 and EST241777) mapped within the PGL1 critical region. We further characterized the genomic organization of the promyelocytic leukemia zinc finger (PLZF) gene that maps within the PGL1 critical region and physically excluded the serotonin receptor type 3 (5HT3R) gene. Finally, we identified a common, silent, single-base substitution polymorphism in the 5HT3R gene and characterized the allele sets of two new highly polymorphic microsatellite repeats within the PGL1 critical region.

Glomus tumours and genomic imprinting: influence of inheritance along the paternal or maternal line

Two new families with glomus tumours and two additions to earlier publications are presented. The pattern of inheritance is autosomal dominant. Familial glomus tumours are inherited almost exclusively via the paternal line, a finding inconsistent with autosomal dominant transmission. This can be explained by genomic imprinting. The maternally derived gene is inactivated during female oogenesis and can be reactivated only during spermatogenesis. Two different loci have been assigned, one to a 5 cM region of chromosome 11q13.1 and one to 11q22.3-q23.3. Genomic imprinting has already been found for the distal locus and here we demonstrate that the proximal locus is subject to genomic imprinting too. Genomic imprinting has considerable implications for genetic counselling in families with glomus tumours. In addition to this the sex ratio among affected offspring appears to be influenced by the paternal or maternal origin of the gene of the transmitting father.

First experiences with genetic counselling based on predictive DNA diagnosis in hereditary glomus tumours (paragangliomas)

Hereditary glomus tumour (MIM 168,000) or paraganglioma (PGL) is a slowly progressive disorder causing benign tumour growth predominantly in the head and neck region. Though benign in nature the tumours can lead to severe morbidity. Inheritance of PGL is autosomal dominant and is strongly modified by genomic imprinting; only a paternally transmitted PGL gene leads to symptoms. A gene for PGL has recently been mapped to 11q22.3-q23. Genetic counselling on the basis of DNA linkage diagnosis was offered in an extended Dutch pedigree. Thirty-two subjects opted for further counselling, of whom 20 applied for DNA testing and participated in a standardised protocol. Sixteen cases had presymptomatic testing (paternal allele); four of these appeared to have the at risk haplotype and in two of them a glomus tumour was subsequently detected on MRI. In one case linkage results were inconclusive (recombination) and one person did not want to learn his test result. Four cases had testing for carrier status (maternal allele) of which one appeared to be a carrier. Our data show that genetic counselling gains significant accuracy when based on parent of origin, sex of the counsellee, and DNA linkage diagnosis. Moreover, a normal DNA result may prevent unnecessary worry and investigations, while an established presymptomatic diagnosis will guide adequate clinical management. The psychological impact of counselling and predictive DNA testing is unclear as yet. Further investigations into the natural history of PGL in gene carriers and into the psychological impact of DNA testing is desirable.

[Congenital familial plaque-shaped glomus tumors. An unusual variant of multiple regional glomus tumors]

Plaque-like glomus tumours are an unusual and very rare clinical form of multiple regional glomus tumours. We report on a 16-year-old girl with this variety of glomus tumours. The irregular angiomatous plaques localized on her back and right hip were present from birth and enlarged with body growth. In addition, there were some bluish nodules scattered on the right mamma, the abdomen and the left shoulder. The family history showed hereditary influences. The proper diagnosis was based on histological and immunohistochemical findings. In the present case report, the clinical, histopathological and immunohistochemical features and the differential diagnosis of multiple plaque-like glomus tumours are discussed.