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.

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.

Gastric multicentric glomangioma: a case report of this rare cause of abdominal pain

BACKGROUND

A glomus tumor is a rare neoplasm derived from glomus cells, specialized cells that surround small blood vessels which are important in regulating peripheral blood flow. Glomangiomas are a subset of glomus tumors. They are usually localized in the skin and subcutaneous tissue. They have also been reported in viscera, most notably in the gastrointestinal tract.

CASE REPORT

A case of gastric multicentric glomangioma is described in an 18-year-old male who presented with chronic continuous abdominal pain over a 4-6 month period. Preoperative diagnosis, operative findings, histology, and immunohistochemistry of the tumor are discussed in detail.

CONCLUSIONS

Case reports of this rare tumor are important because of the paucity of studies noted in the gastro-intestinal literature as a result of poor identification prior to the advent of modern immunohistochemistry. The significance of accurately diagnosing a gastrointestinal glomangioma is crucial for appropriate treatment.

Glomus tumor of the kidney: a report of 3 cases involving renal parenchyma and review of the literature

Glomus tumor is a rare mesenchymal neoplasm affecting the subcutaneous tissue of the distal extremities in the majority of cases. It only rarely involves visceral organs. We report 3 cases of the glomus tumor family in the kidney, a solid glomus tumor, a glomangioma, and a glomangiomyoma. All 3 tumors involved the renal parenchyma and occurred in 3 men aged 36, 81, and 48 years, respectively. All 3 tumors were well-circumscribed and showed morphology otherwise identical to those seen in soft tissue. All 3 tumors were immunoreactive for actin and negative for desmin and S100 and only 1 tumor expressed CD34 in tumor cells. To date, all 3 tumors have followed a benign course without evidence of recurrence or metastasis. This report expands the spectrum of mesenchymal tumors of the kidney.

Gastric solid glomus tumor and multiple glomangiomyomas of the large bowel with intravascular spread, multifocal perivascular proliferations and liver involvement

The authors present a case of multiple glomus tumors (GTs) of the gastrointestinal tract, representing the type of a gastric glomus tumor proper and large bowel glomangiomyomas with myopericytoma-like features, observed in a 46-year old female, with multifocal perivascular proliferations of primitive cells and hepatic involvement. Histologically, the multilobular gastric tumor and hepatic lesions corresponded to a typical glomus tumor, while the tumor situated in the transverse colon, up to 7 cm in diameter, presented as a glomangiomyoma infiltrative (with myopericytoma-like foci), and satellite tumors in the large bowel mucosa, 0.5-0.7 cm in diameter, represented small glomangiomyomas. In addition, the patient demonstrated two types of concomitant vascular lesions: 1/ intravascular spread in the form of neoplastic plugs that obliterated the lumen of medium-size veins, and 2/ microscopic perivascular proliferation of primitive, small cells seen in the vicinity of the main tumor and in the adjacent adipose tissue. The patient has been ill for 2.5 years; she has been subjected to a partial colectomy with a resection of the small intestinal loop, greater omentum and the right ovary, followed by chemotherapy. At present, she is stable, and the infiltration--especially in the epigastric region--has decreased. The picture may confirm the theory that multiple GTs develop in association with multifocal proliferation of perivascular stem cells, as well as that their ability to penetrate into the lumen of large vessels gives origin to satellite tumors, which are not necessarily metastatic. It seems that at present, the group of perivascular SMA+ tumors may include infantile-type myofibromatosis in adults, myopericytoma, glomangio(myo)pericytoma, glomangiomyoma, glomus tumor proper, and glomangioma. Most likely, also some tumors previously classified as hemangiopericytomas belong to this group. The distinctive feature present in at least some of the above listed perivascular tumors is their synchronous or metachronous growth in a particular region and their ability to occupy intravascular space as nodules or solid bands, which in turn may give origin to satellite tumors. Multifocal lesions associated with a short survival in a given patient will obviously support the presence of metastatic disease. In the remaining cases, determination whether the patient has metastatic disease requires deep consideration and caution, also while deciding on treatment to be employed.

Primary glomangioma of the esophagus mimicking esophageal papilloma

We report a case of glomangioma of the esophagus in a 28-year-old woman who presented with a 3-year history of vague discomfort, pain and heat in the neck. At initial gross examination, the tumor mimicked an esophageal papilloma. The resected esophageal specimen contained a polypoid, whitish-gray mass, which measured 3 cm in maximum diameter. Microscopically the tumor consisted of loose fibrovascular stroma heavily infiltrated with mononuclear inflammatory cells and covered with focally hyperkeratotic, parakeratotic and acanthotic squamous epithelium without atypia. In the deeper area immediately above the true muscular layer of the esophageal wall, microscopical examination revealed the neoplasm consisting of numerous, small-to-medium branched vessels covered by regular endothelium and filled with erythrocytes. The loose stroma around the vessels contained poorly circumscribed nests of small, round to oval cells with a uniform appearance. Immunohistochemically, the tumor cells were immunoreactive for smooth muscle actin and vimentin and non-immunoreactive for CD34, CD117, desmin, pan-cytokeratin, synaptophisin, neuron-specific enolase and S-100 protein. Despite its bland histology, the infiltrative growth pattern was suggestive of aggressive behavior; thus, an appropriate clinical follow-up was recommended. An accurate diagnosis and an understanding of the behavior of these rare tumors, especially in an unusual location, are crucial to their management and clinical outcome.

Malignant Glomus Tumor

Malignant glomus tumor (MGT) is a rare, recently described neoplasm that recapitulates the appearance of the modified smooth cells of the normal glomus body. We report a case of MGT of the hand of a 48-year-old woman. Magnetic resonance imaging (MRI) showed a 2.8-cm, well circumscribed, enhancing mass on the volar aspect of the thenar region of the right hand in immediate continuity with the ulnar artery and nerve. Computed tomography scan (CT-Scan) of the chest was normal. Histologic evaluation revealed a multilobular lesion with prominent branching capillary vasculature and perivascular arrangement of sheets of tumor cells. The tumor cells were round, relatively uniform in size with distinct cell borders and perinuclear cytoplasmic clearing. They were of intermediate to high nuclear grade and showed significant mitotic activity. A wide local excision with negative margins was performed. Multiple lung metastases were evident at 8-month follow-up. To date, forty-five cases of MGT of skin and soft issue have been reported in the literature. Twelve of the forty-five cases developed metastasis. In this report, we emphasize the differential diagnosis of MGT in the skin and deep soft tissue.

Invasive glomus tumor of the nasal cavity

Glomus tumors are neoplasms that occur only rarely in the head and neck. These tumors are usually distinguished by benign growth characteristics. We present a case of a large intranasal glomus tumor which, at presentation, had eroded through the ethmoid roof to involve the floor of the anterior cranial fossa. The patient was treated with primary external-beam radiotherapy. To our knowledge, this is the first report of an invasive glomus tumor of the head and neck.

[Clinicopathologic characteristics of myopericytoma]

OBJECTIVE

To investigate the clinicopathologic characteristics and differential diagnosis of myopericytoma.

METHODS

Six cases of myopericytomas were analyzed by light microscopy and immunohistochemistry (LSAB detection method).

RESULTS

Tumors from 3 females and 3 males were found on the extremities and chest wall. The ages of these 6 patients ranged from 16 to 58 years. Histologically, all tumors were unencapsulated. The neoplastic cells were oval to spindle shaped with eosinophilic cytoplasm, had a myoid appearance and showd areas of concentric perivascular proliferation around lesional blood vessels which were present with focal myxoid stroma. Morphologically in some cases the tumor overlap myofibroma, hemangiopericytoma or glomus tumor. One tumor was located entirely within the lumen of a vein. In another case, the tumor displayed cellular pleomorphism, mitotic activity, necrosis should be diagnosed as malignant myopericytoma. The neoplastic cells were positive for SMA and negative for CD31, CD34, S-100, and CK.

CONCLUSIONS

Myopericytoma is composed of oval to spindle shaped myoid cells with a striking tendeny for concentric perivascular growth. These cells differentiate towards perivascular myoid cells or myopericytes. Extremely rare malignant myopericytoma exist.

Gastric glomus tumor

Gastric glomus tumors are rare neoplasms that may present with upper gastrointestinal symptoms, or may be discovered incidentally. They may mimic other tumors both grossly and microscopically. They are usually benign and, although the exceptional case with aggressive behavior cannot be reliably predicted, large size may be of prognostic importance. We describe a 3.8 cm gastric glomus tumor in a patient who also had adenocarcinoma arising in an adenoma of the rectum, and discuss the differential diagnosis and prognosis.

Glomus tumor of the trachea: value of multidetector computed tomographic virtual bronchoscopy

Glomus tumor of the trachea is extremely rare. We report a case of tracheal glomus tumor in a 39-year-old man who presented with hemoptysis. The diagnosis was made after bronchoscopic biopsy of a tumor involving the posterior wall of the upper trachea. Thin-section multidetector computed tomography of the chest was performed before surgical resection, with multiplanar re-formations and 3-dimensional virtual bronchoscopic reconstruction. Tracheal sleeve resection with reconstruction was successful, and pathological studies confirmed complete resection and the diagnosis of glomus tumor. The patient was disease-free 3 months postoperatively. To our knowledge, this is the first reported case in which additional computed postprocessing was used to help evaluate the extent of such a tumor.

Malignant glomus tumor of the lung

Primary malignant glomus tumors of the lung are extremely rare, and to our knowledge, only three cases have been described to date. We report one such case in a 53-year-old man who presented with a persistent dry cough. Chest computed tomography scans demonstrated an irregularly shaped mass in the right lower lobe of the lung. Many small nodules were distributed from the main tumor to the periphery, along with bronchovascular bundles. Right lower lobectomy was performed under the diagnosis of lung tumor. The tumor was located in the proximal portion of the right lower lobe and extended along the pulmonary arteries. Histological examination revealed a sheet-like proliferation of epithelioid glomus cells and fascicles of spindle cells. The presence of increased mitotic activity, tumor necrosis and prominent intravascular invasion suggested malignancy. The tumor cells were immunoreactive for vimentin, calponin, h-caldesmon, and alpha-smooth muscle actin, which indicated definitive smooth muscle differentiation. We believe that this is the fourth reported case of malignant glomus tumor of the lung.

Primary pulmonary glomus tumor with contiguous spread to a peribronchial lymph node

Glomus tumors are uncommon soft tissue tumors. Rare occurrences in visceral organs including the respiratory tract have been reported. The vast majority of these tumors are biologically benign. We report a case of primary pulmonary glomus tumor with atypical features characterized by mild nuclear atypia, local infiltration, and contiguous spread to a peribronchial lymph node. The current literature is reviewed.

Intranasal pericytic tumors (glomus tumor and sinonasal hemangiopericytoma-like tumor): report of two cases with review of the literature

An intranasal glomus tumor and a sinonasal hemangiopericytoma-like tumor are reported. Both patients were elderly women suffering from nasal bleeding, and presented with a polypoid mass arising in the nasal septum. Microscopically, the glomus tumor displayed a proliferation of uniform rounded or cuboidal epithelioid cells arranged in sheets and interrupted by a rich vasculature with a characteristic configuration mimicking the normal glomus bodies, while the sinonasal hemangiopericytoma-like tumor featured a perivascular proliferation of spindle- to oval-shaped cells that were arranged in short fascicles. Both tumors shared immunohistochemical features supporting their myoid differentiation by the expression of vimentin, alpha-smooth muscle actin and muscle-specific actin, albeit with no immunoreaction to desmin. Both the intranasal glomus tumor and sinonasal hemangiopericytoma-like tumor are characterized by a perivascular growth pattern and myoid differentiation, having a close relation to the 'perivascular myomas', which was recently designated.

Clinical value of somatostatin receptor imaging in patients with suspected head and neck paragangliomas

Paragangliomas or glomus tumours of the head and neck region are rare somatostatin receptor-expressing neuroendocrine tumours. Precise preoperative diagnosis is of special importance in order to adequately weigh the potential benefit of the operation against the inherent risks of the procedure. In this study, the clinical value of somatostatin receptor imaging was assessed in 19 patients who underwent somatostatin receptor scintigraphy because of known or suspected paraganglioma of the head and neck region. The results were compared with the results of computed tomography and/or magnetic resonance imaging, histology and clinical follow-up. [(111)In-DTPA- D-Phe(1)]-octreotide scintigraphy was performed 4-6 and 24 h after i.v. injection of 140-220 MBq (111)In-octreotide. Whole-body and planar images as well as single-photon emission tomography images were acquired and lesions were graded according to qualitative tracer uptake. Somatostatin receptor imaging was positive in nine patients, identifying paragangliomas for the first time in three patients and recurrent disease in six patients. In one patient, a second, previously unknown paraganglioma site was identified. Negative results were obtained in ten patients. These patients included one suffering from chronic hyperplastic otitis externa, one with granuloma tissue and an organised haematoma, one with an acoustic neuroma, one with an asymmetric internal carotid artery, two with ectasia of the bulbus venae jugularis and one with a jugular vein thrombosis. In two patients with a strong family history of paraganglioma, individual involvement could be excluded. In only one patient did somatostatin receptor imaging and magnetic resonance imaging yield false negative results in respect of recurrent paraganglioma tissue. It is concluded that somatostatin receptor scintigraphy provides important information in patients with suspected paragangliomas of the head and neck region and has a strong impact on further therapeutic management.

Glomangiomatosis

Neoplasms containing glomus cells are uncommon. Glomus cells within an angiomatosis, so called glomangiomatosis, is exceedingly rare with only three previously reported cases. We are describing the fourth case from a 17-year-old boy which involved his left hand, fingers, and distal forearm. We will review the previously reported cases.

CD34-positive glomus tumor: clinicopathologic and immunohistochemical analysis of six cases with myxoid stromal changes

BACKGROUND

Glomus tumors are benign, mainly superficially located perivascular neoplasms, composed of cytologically characteristic neoplastic cells staining immunohistochemically positive for vimentin and muscle actin, closely associated with often branching blood vessels.

METHODS

Six cases of glomus tumor were analysed histologically and immunohistochemically.

RESULTS

We report six cases of glomus tumor (three solid glomus tumors, two glomangiomas, one glomangiomyoma) arising on the fingers of adult patients (five female and one male patient; age range 35-65 years) that showed prominent myxoid stromal changes and immunohistochemically a coexpression of alpha-smooth muscle actin and CD34 by neoplastic cells.

CONCLUSIONS

Neoplastic cells in glomus tumor may show a coexpression of alpha-smooth muscle actin and CD34, an important finding regarding the differential diagnosis of these lesions and the relationship of perivascular neoplasms.

Sinonasal haemangiopericytoma-like tumour: a sinonasal glomus tumour or a haemangiopericytoma?

AIMS

Sinonasal haemangiopericytoma-like tumour is controversial with regard to its nosologic nature. This study aims to investigate its relationship with glomus tumour and haemangiopericytoma.

METHODS AND RESULTS

Six cases of sinonasal haemangiopericytoma-like tumours identified in our files were reviewed for clinicopathological features, and compared with five cases each of soft tissue glomus tumour and meningeal haemangiopericytoma. Immunohistochemical studies for muscle-specific actin, smooth muscle actin, desmin and CD34 were performed. Sinonasal haemangiopericytoma-like tumour demonstrated a uniform histological appearance with bland-looking short, spindly cells forming sheets and short fascicles. The tumour cells were interspersed with slit-like, round and ectatic blood vessels. Actin immunoreactivity was demonstrated in all six cases, although occasionally patchy. The histological appearance and immunohistochemical phenotype of sinonasal haemangiopericytoma-like tumour were very similar to and focally indistinguishable from glomus tumour. Meningeal haemangiopericytoma, in contrast, was characterized by high tumour cellularity, random nuclear orientation, presence of staghorn vasculature and lack of immunohistochemical evidence of myogenic differentiation.

CONCLUSIONS

We conclude that sinonasal haemangiopericytoma-like tumour is biologically close to or identical to glomus tumour, but is not related to haemangiopericytoma.

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.

Glomus tumors with cystic changes around the ankle

Sizable glomus tumors with cystic changes in the ankle are extremely uncommon. This paper describes painless glomus tumors with cystic changes arising in the ankle of a 22-year-old woman. At the age of 14, a painless mass was noticed on the lateral side of the left ankle, and at age 21, another mass appeared on the medial side of the same ankle. Magnetic resonance imaging (MRI) and computed tomography (CT) scanning revealed 4.5 x 4.0 cm and 2.0 x 2.0 cm sized masses on the medial side and a 3.0 x 4.0 cm sized cystic mass on the lateral side of the ankle. The tumors were removed en bloc. Microscopically, the tumor consisted of perivascularly arranged cells with punched-out, round, and regular nuclei. Immunohistochemically, the tumor cells expressed SMA and HHF-35, indicating smooth muscle cell characters. The patient had no recurrence at 2 years after surgery.

Malignant glomus tumor in the branchial muscle of a 16-year-old girl

Malignant glomus tumor is an extremely rare neoplasm and its histological features are not well characterized. We report a 16-year-old female patient with a malignant glomus tumor. The patient was admitted to our hospital presenting with a mass in the right upper arm that she had noticed for the previous 6 months. Computed tomography and magnetic resonance imaging revealed an expanded mass involving the surrounding tissues. At surgery, an ill-defined and expanded mass was found, 5 x 4 x 3 cm in size, in the right branchial muscle. The tumor was extirpated, along with neighboring muscle tissues. Histologically, tumor cells were round to short-spindle shaped, forming solid sheets admixed with vessels of varying size. Their nuclei were uniformly oval to round, and their cytoplasms were slightly eosinophilic. The growth pattern of the tumor cells resembled that of glomus tumor, but mitotic figures were frequent (as high as 10 per 10 high-power fields). Immunohistochemically, the tumor cells were positive for vimentin and muscle actin, but negative for desmin. There were no areas typical of benign glomus tumor or sarcomatous change. These findings led us to a diagnosis of primary malignant glomus tumor arising de novo. There has been no recurrence or metastasis for 21 months after wide excision.

Infiltrative glomus tumor arising from a benign glomus tumor: a distinctive immunohistochemical pattern in the infiltrative component

Malignant glomus tumors (MGT) are rare. Although metastatic MGT has been reported, most MGT have only been locally aggressive, some with multiple local recurrences. We report an additional case of an infiltrative glomus tumor. In addition to the pattern of immunohistochemical staining for alpha-smooth muscle actin (SM-actin) previously described, we performed immunohistochemical stains for Ki-67 and CD34. The infiltrative component of the glomus tumor showed variably decreased staining with SM-actin and occasional tumor cells showed nuclear staining with Ki-67. CD34 staining occurred in stromal cells forming the pseudocapsule in the benign component of this tumor and in other benign glomus tumors. The infiltrative component showed increased CD34 stromal cells. Although Ki-67 staining showed only an occasional proliferative cell, the immunohistochemical staining pattern of CD34 and SM-actin raise the possibility that the infiltrative component of this tumor may have differences in the degree of differentiation from the circumscribed part and that local factors could support its spread from a conventional benign glomus tumor.

Congenital multiple plaque-like glomangiomyoma

Congenital glomus tumor is a rare clinical variant of glomus tumor, and glomangiomyoma is the least frequent histologic type of glomus tumor. We report a case of congenital multiple plaque-like glomangiomyoma in a 38-year-old man with multiple nodules and plaques on his left arm and forearm. Histopathologic study showed an angiomatous, nonencapsulated tumor with numerous highly folded dilated vascular lumina scattered throughout the dermis. The lumina were lined by a single layer of flat endothelial cells, and one to several rows of glomus cells were observed adjacent to the endothelial cells. Around large vessels, there was a gradual transition from glomus cells to elongated mature smooth muscle cells with thin and long "blunt-ended" nuclei. Immunohistochemically, there were strong positive reactions for cytoplasmic alpha-smooth muscle actin in glomus cells and smooth muscle cells, vimentin in glomus cells and endothelial cells, and desmin in the smooth muscle cells only. To our knowledge, this is the first case report of congenital multiple plaque-like glomus tumor with the microscopic appearance of a glomangiomyoma.

Nasal glomus tumors: report of two cases with emphasis on immunohistochemical features and differential diagnosis

We describe 2 cases of nasal glomus tumor that presented as nasal polyps. Grossly, each of the polypectomy specimens consisted of small fragments of polypoid soft tissue with glistening mucosa. Histopathological examination of each of the specimens showed sheets and nests of monomorphic round cells intimately associated with capillary-sized blood vessels. The tumor cells were strongly cytoplasmic positive for vimentin, smooth-muscle specific actin, muscle-specific actin, and CD34. Collagen IV showed pericellular positivity. Nasal glomus tumors are extremely rare and represent less than 0.5% of nasal nonepithelial tumors. Nasal polyps are common surgical pathological specimens, with the majority of nasal polyps being inflammatory polyps or a respiratory epithelial proliferation. Histologically, many nasal polyps show vascular proliferation with an inflammatory cell infiltrate, which may be confused with the rare glomus tumor. In addition, other nasal vascular tumors, in particular nasal hemangiopericytoma and neural tumors, may histologically mimic nasal glomus tumors.

Catecholamine secreting glomus tumor detected by iodine-123-MIBG scintigraphy

We report the case of a 41-yr-old woman who presented with arterial hypertension and tinnitus in the right ear synchronous with pulse. She had previously undergone surgery for suspected pheochromocytoma without positive therapeutic effect. CT and MRI revealed a homogenous tumor with contrast enhancement in the right hypotympanon and foramen jugulare, and [123I]metaiodobenzylguanidine (MIBG) scintigraphy demonstrated strong tracer uptake in the same area. Selective venous sampling of catecholamines in the ipsilateral jugular vein confirmed the tumor to have originated from hormone production.

Epithelioid glomus tumor

Reported are five cases of an unusual histological variant of glomus tumor that we have designated epithelioid glomus tumor. Unlike conventional glomus tumors, which consist of small polygonal cells with dark round nuclei and scanty cytoplasm, the epithelioid lesions were composed of large polygonal to spindle-shaped cells with abundant eosinophilic cytoplasm and large, irregularly shaped nuclei: The cells had both epithelioid and myoid qualities. Two of the cases studied were predominantly epithelioid, with small remnants of conventional glomus tumor at the periphery. The three other lesions were purely epithelioid. Epithelioid glomus tumors are of particular importance because they may be mistaken for other lesions histologically. Both benign and malignant epithelial lesions may be considered in the differential diagnosis; spindle-cell lesions, such as schwannoma, leiomyoma, hemangiopericytoma, and others, are in the histological differential diagnosis. Immunohistochemical and ultrastructural studies indicated that epithelioid glomus tumors had characteristics identical to those of conventional glomus tumors: the cells showed features consistent with smooth muscle derivation. The epithelioid areas frequently exhibited cytological atypicality--features that we believe to be a manifestation of cellular degeneration or senescence (analogous to "ancient" change in schwannomas or symplastic change in leiomyomas) rather than evidence of neoplastic progression. Simple surgical excision seems to have been curative (mean duration of follow-up of 4 years in the three cases in which such information was available). To our knowledge, no similar cases have previously been reported.

In situ expression of beta 1, beta 3 and beta 4 integrin subunits in non-neoplastic endothelium and vascular tumours

Endothelial cells play an important role in adhesive interactions between circulating cells and extracellular matrix proteins. In vitro studies have shown that many of these processes are mediated by a superfamily of alpha beta heterodimeric transmembrane glycoproteins called integrins. The distribution patterns of beta 1, beta 3 and beta 4 integrin subunits in endothelial cells (EC) in situ were examined immunohistochemically on serial frozen sections of a wide range of non-neoplastic tissues and of vascular tumours, both benign and malignant. Expression of the beta 1 subunit was a constitutive feature of EC. Among the beta 1-associated alpha subunits, alpha 5 and alpha 6 were broadly distributed in EC, irrespective of vessel size and microenvironment. The alpha 3 subunit displayed intermediate levels of expression with a slight preference for small vessel EC. Presence of alpha 1 was confined to EC of capillaries and venules/small veins. Expression of alpha 2 in EC was inconsistent. With rare exceptions, the alpha 4 chain was absent in EC. The beta 3 and alpha v subunits were expressed in most EC, though not always concomitantly. In contrast to the beta 1 chain, however, these integrin subunits were absent in EC of glomerular capillaries and were expressed variably in sinusoidal EC. The beta 4 chain was evenly present in the great majority of EC, except for those of large vessels. In vascular tumours, the patterns of beta 1 and alpha 1 to alpha 6 subunit expression generally corresponded to those found in their non-neoplastic counterparts. Expression of beta 3, alpha v and beta 4 chains, however, decreased in neoplasia, especially in angiosarcomas. These data show that EC dispose of broad and at the same time differential repertoires of integrin subunits that presumably reflect vessel-type associated functional differences among these cells. In vascular tumours, the orthologous distribution patterns of beta 1 and alpha 1 to alpha 6 chains are conserved in most instances while the amounts of beta 3, alpha v and beta 4 subunits expressed in EC tend to decrease in the course of malignant transformation.

Glomus tumor. A histological, histochemical and immunohistochemical study of the various types

Glomus tumors are benign lesions composed of vessels and glomocytes in varying proportions. The histological appearance of the tumors depend upon the ratio of the vascular to the glomus cells and their differentiation as well as upon the amount and composition of the stroma. The aim of the present study was the establishment of criteria for the distinction of glomus tumor-like malformations from neoplasms with glomus cell differentiation. Using a panel of monoclonal and polyclonal antibodies (vimentin, a-smooth muscle actin, desmin, pan-keratin, low molecular weight cytokeratin, EMA, NSE, S-100 protein, Factor VIII, a1-ACT) glomus tumors could be separated into three types: vascular, cellular with myxoid stroma and cellular, solid type. In the first two types the tumor growth is composed of all three components found in normal glomus body, but in a haphazard fashion and thus might be considered as tumor-like malformations. The third type is composed of perivascular arranged cells most of which acquire the phenotypical characteristics of glomocytes. This last tumor probably represent the neoplastic variant of the group of lesions designated by the term glomus tumor.

Aggressive glomus tumor of the nasal region. Report of a case with multiple local recurrences

We describe a locally aggressive glomus tumor that occurred in the nasal region of a 32-year-old woman. The neoplasm recurred six times over a period of 14 years following the initial excision. This aggressive behavior resulted in problems with the diagnosis of the neoplasm. Although grossly cystic, the tumor contained large areas with a solid growth pattern and exhibited an infiltrative margin. There was no cytological atypia, mitoses were scanty, and necrosis was absent. The neoplasm did not metastasize.

Malignant glomus tumor originating in the superior mediastinum--an immunohistochemical and ultrastructural study

An extremely rare case of malignant glomus tumor originating in the superior mediastinum was evaluated immunohistochemically and ultrastructurally. A 78-year-old woman who had been suffering from dysphagia and dyspnea had poorly-defined soft tissue mass, 4.5 x 2.5cm, in the superior mediastinum with direct invasion into the esophagus, trachea, and bilateral thyroid glands. This case is believed to be unique in several respects. There were neither recognizable findings of benign glomus tumor nor sarcomatous areas, in contrast to the previously reported cases. A definite direct invasion into the surrounding organs was identified. We therefore interpreted this case as primary malignant glomus tumor, not as glomangiosarcoma arising in a benign glomus tumor.

Intravascular glomus tumour: a previously undescribed phenomenon

We report the first case of an intravascular glomus tumour, which was located in the right forearm of a 40-year-old male. Microscopically the lesion originated from the wall of a vein and protruded into the lumen of the affected blood vessel. The tumour cells were characterized immunohistochemically by the presence of vimentin, actin and myosin. Within the tumour, small nerves, immunopositive for S-100 protein and neurofilaments, could be identified. Histogenetically, the tumour is thought to derive from intramural epithelioid cells of the venous part of an arteriovenous anastomosis.

Intraosseous glomus tumor in the sacrum. A case report

Primary intraosseous glomus tumor is rare and may occur in the medullary cavity of bone. A 22-year-old woman with a one-year history of spontaneous and persistent sacral pain was found to have an intraosseous glomus tumor in this unusual location. Curettage was followed by complete relief from pain. This case of glomus tumor originating in the sacrum is thought to be the first reported in the world literature.

Glomus tumours: an immunohistochemical profile of 11 cases

We studied 11 glomus tumours immunohistochemically, with a panel of connective tissue and epithelial markers. Most tumours contained small nerve fibres located in connective tissue septae between groups of glomus cells, thus accounting for the frequent occurrence of pain associated with glomus tumours. All tumours stained positively for muscle-specific actin and vimentin. Immunostaining for high and low molecular weight cytokeratins, desmin, myoglobin, S-100 protein, neurofilaments and Factor VIII related antigen was negative. Our findings confirm and amplify the proposed smooth muscle histogenesis of glomus tumours. This immunohistochemical profile may be of diagnostic value in the differential diagnosis of atypical glomus tumours.

Glomangiosarcoma in a glomus tumor. An immunohistochemical and ultrastructural study

An extremely rare case of glomangiosarcoma (GS) occurring in a glomus tumor (GT) was evaluated ultrastructurally and histochemically. A man 65 years of age who was suffering from back pain underwent resection of a deep cutaneous nodule. Cells of a solid type GT showed numerous subplasmalemmal pinocytotic vesicles, thin filaments with scattered dense bodies, and thick external lamina, but negative desmin staining and a lack of glycogen. Similar findings also were observed in the GS, but were less obvious. The GS compressed the surrounding GT, exhibited many mitotic figures, prominent nucleoli, elongated nuclei and cytoplasm, and reacted more strongly to vimentin staining than the GT. The GT contained S-100 protein-positive Schwann cells, a few substance P-positive nerve fibers, and moderate numbers of infiltrating mast cells. None of these findings were observed in the GS. Results were consistent with the view that GS was transformed possibly from the GT, and that the good prognosis for GS may be due to its small size that may be related to the preexistence of a pain-causing GT.

Oncocytic glomus tumour: a new variant

A new variant of glomus tumour characterized by oncocytic change is reported. The light and electron microscopy and immunohistological findings are described. This is the first reported case of an oncocytoma of non-epithelial origin.

Renin secretion from malignant pulmonary metastatic tumour cells of vascular origin

1. A pulmonary chemodectoma/glomangiosarcoma that had metastasized from the thigh was studied after removal from a 22 year old Algerian patient with hypertension, high plasma prorenin and signs of secondary aldosteronism. 2. Renin and renin mRNA were localized in sections of the tumour tissue using monoclonal anti-human renin antibody and human renin cDNA probe, respectively. 3. The cells grew prolifically in culture, but, even though their renin content was similar to that of transfected human juxtaglomerular cell tumour cells (approximately 1 pg/microgram DNA), their rate of secretion of renin was much lower (0.05-0.15 cf. 0.5-1.5 pg/h per microgram DNA). 4. Forskolin (10 mumol/l for 24 h) increased secretion of renin from 1.9 +/- 0.36 to 4.1 +/- 0.64 pg/ml per h of culture (P less than 0.001, n = 11), consistent with cAMP being a second messenger in the secretory mechanism. 5. The cells should provide valuable information about intracellular mechanisms for the regulation of renin synthesis and secretion.

Glomus tumor of the lip. A case report and immunohistochemical study

A rare glomus tumor of the lip is reported and--with nineteen glomus tumors from other sites--examined immunohistochemically with both monoclonal and polyclonal antibodies. In every case, the glomus cells showed strong reactivity with antivimentin, and factor VIII-related antigen was consistently identified in the endothelial cells but not in the glomus cells. Antiblood group A antigen was located in endothelial cells in nine cases; of these nine, five also showed focal staining in glomus cells. In no case was there reactivity with antibodies to common leukocyte antigen or cytokeratin proteins. These results support the hypothesis of Tajima et al. that the glomus cell is transitional--between smooth muscle and vascular endothelium--being essentially a modified, smooth muscle cell with some endothelial cell properties.

Glomus tumor of the cheek: an immunohistochemical demonstration of actin and myosin

A rare case of a buccal glomus tumor was examined by light and electron microscopy. Histologically, the tumor consisted of various vascular spaces surrounded by masses of epithelioid glomus cells, coexisting with a hemangiomatous proliferation of the vessels. Immunohistochemical stainings revealed that the tumor cells were positive for smooth-muscle actin and myosin, with various intensities of the stainings. The electron microscope invariably showed microfilaments in the tumor cells. The results suggest that the glomus tumor cells have characteristics of the smooth-muscle cell and the tumor has a hamartomatous nature.

Endocrine-type granules in cells of glomus tumor of the stomach

The ultrastructure of a gastric glomus tumor was studied. The tumor cells were found to possess structural features similar to those of smooth muscle cells. In addition, hitherto undescribed granules of endocrine type and cilia were identified.