Diagnosis of gastric glomus tumor by endoscopic ultrasound-guided fine needle aspiration biopsy. A case report with cytologic,histologic and immunohistochemical studies

BACKGROUND: The majority of glomus tumor are small, benign neoplasms that arise from modified smooth muscle cells. They usually occur in the dermis or subcutis of the extremities. However, rare cases have been reported in the visceral locations, most often in the stomach. CASE: A 32-year-old woman presented with episodes of right upper quadrant pain. She was found to have a gastric tumor that was biopsied at another hospital, where the diagnosis of gastrointestinal stromal tumor (GIST) was made. Endoscopic ultrasound (EUS) performed at our institution revealed a gastric submucosal tumor that was then biopsied by fine needle aspiration (FNA). Cytology revealed cohesive clusters of uniform, round, small cells with ill-defined cytoplasmic borders and scanty, amphophilic cytoplasm. Nuclei were round, with smooth nuclear membranes and evenly distributed, dusty chromatin. Intermingled with those epithelioid cells were small, short, spindled, normal endothelial cells. Immunohistochemical studies performed on cell block showed that the tumor cells were negative for CD34, CD117, chromogranin, synaptophysin, desmin and AE1/AE3 and were strongly positive for SMA, HHF-35 and collagen type IV. Glomus tumor was diagnosed and later confirmed by histology. CONCLUSION: EUS-guided FNA biopsy is efficient and permits adequate sampling for accurate diagnosis of gastric glomus tumor. Although rare, glomus tumor should be in the differential diagnosis among other gastric lesions, such as well-differentiated adenocarcinoma, epithelioid GIST and carcinoid tumor.     

Histochemically demonstrable increase in the catecholamine content of the carotid body in adult rats treated with methylprednisolone or hydrocortisone

Synopsis Carotid bodies of adult albino rats were examined using the formaldehyde-induced fluorescence (FIF) method for the demonstration of fluorogenic monaomines and staining with I% Toluidine Blue for morphological observations.In the carotid body of normal controls, most glomus (principal or type I) cells exhibited a FIF presumably due to catecholamines. The intensity of the fluorescence was weak in most cells, while some glomus cells were non-fluorescent and others exhibited a moderate or intense FIF. The sustentacular (satellite, supporting or type II) cells were essentially non-fluorescent.One week after the administration of a single intraperitoneal injection of the long-acting glucocorticoid 6-methylprednisolone sypionate (400 mg/kg) or after seven intraperitoneal injections of the water-soluble glucocorticoid hydrocortisone sodium succinate (40 mg/kg daily for a week), a distinct increase was observed in the FIF of the glomus cells. No non-fluorescent glomus cells were observed after treatment with either glucocorticoid, and the intensity of most fluorescent glomus cells was moderate or intense.It is concluded that glucocorticoids cause an increased storage of catecholamines in the glomus cells of the carotid body of the adult rat, an observation of interest in view of the fact that such changes due to glucocorticoids have as yet been reported only in catecholamine-storing cells of newborn rats.     

Improved demonstration of exocytotic profiles in glomus cells of rat carotid body after perfusion with glutaraldehyde fixative containing a high concentration of potassium

Extensive secretion by exocytosis was demonstrated in the glomus (type I) cells of the adult rat after perfusion of carotid bodies with a potassium-rich (high K) glutaraldehyde fixative. Similar secretory profiles were very rare with a glutaraldehyde fixative containing a low concentration of potassium (low K). The increase in the incidence of exocytotic profiles in glomus cells with the high K fixative was highly significant, whereas no statistical difference could be observed in the incidence of coated pits with the different fixatives. Exocytotic profiles were characterized by the following features: (1) they predominated in non-synaptic regions, but were occasionally observed near synapses between two glomus cells; they were not observed near synapses between glomus cells and nerve terminals; (2) extruded electron-dense material associated with coating of the cell membrane was frequent; (3) different stages of dissolution of the extruded granule material was evident. The possible role of exocytosis as a mode of secretion in the glomus cells and the characteristics of the new high K-glutaraldehyde fixative are discussed.     

Digital glomus tumors: a 29-year experience with a lateral subperiosteal approach

The excision of distal digital glomus tumors has traditionally been performed directly over the involved nail bed. This can lead to nail deformities that are often unacceptable for the surgeon and the patient. The authors describe their experience with successful excision of digital glomus tumors using a lateral subperiosteal approach, which creates a dorsal flap. In 29 years, 19 patients were diagnosed with digital glomus tumors. All patients underwent excision using the lateral subperiosteal approach. The mean tumor size was 0.52 cm. The tumors were located on the pulp of the distal phalanx in two patients (10.5 percent) and subungually in 17 patients (89.5 percent). In all patients, preoperative clinical diagnosis was confirmed postoperatively with the biopsy result. Complications occurred in only two patients and included one paronychia and one temporary nail loss. The overall recurrence rate was 15.7 percent. All patients remained asymptomatic after surgery and regained full active and passive range of motion. There were no nail deformities by this approach. This technique represents a safe and effective approach to excising digital glomus tumors.     

Electron-dense endoplasmic reticulum-like profiles closely associated with mitochondria in glomus cells of the carotid body after fixation with oxalate

Fixation in the presence of oxalate was used to demonstrate the electron-dense Ca2+ precipitates in the endoplasmic reticulum in glomus cells of the carotid body. Glomus cells in intact carotid bodies or cells dissociated from the organ by treatment with collagenase were studied electron microscopically. In the intact organ as well as in dissociated glomus cells, electron-dense endoplasmic reticulum-like profiles were seen closely associated with mitochondria, while these lacked reaction product. The interspace between mitochondria was occupied by electron-dense, slightly distended ER, which appeared to contact the outer membrane of the mitochondria. Occasionally, a mitochondrion was in contact with several ER profiles or the ER formed an electron-dense 'cap' on the mitochondrion. The electron-dense precipitates could be removed from ultrathin sections with the calcium chelator ethyleneglycol-2(2-aminoethyl tetra-acetic acid) (EGTA). It is tentatively suggested that the endoplasmic reticulum could be involved in intracellular buffering of Ca2+ in the glomus cell, as has been previously suggested for neurons.     

大鼠颈动脉体球细胞缺氧时膜电位变化与球细胞大小的关系

用细胞内记录法测定了８５个分离培养的大鼠颈动脉体球细胞的膜电位,并由显微照相法记录球细胞的形态进而以测微器测量球细胞的直径。由连二亚硫酸钠（Ｎａ２Ｓ２Ｏ４）造成缺氧（ＰＯ２,１．３－８．０ｋＰａ）。不同直径的球细胞对缺氧有两种不同反应：直径为８．０４±１．０９μｍ的球细胞对缺氧的反应均为去极化,直径为１４．３８±４．２１μｍ的球细胞对缺氧反应为超极化。因此似可认为,球细胞存在功能不同的亚型。缺氧程度不同对球细胞膜电位的改变也有一定影响,缺氧程度严重可使小型球细胞的去极化程度增加,但缺氧程度的高低不能改变两型球细胞对缺氧反应的固有型式。     

Glutamate in the glomus cells of the cat carotid body: Immunocytochemistry and in vitro release

The identity of the postulated excitatory transmitter released by glomus cells is not known. Since our preliminary work on paraffin sections of the cat carotid body indicated that most glomus cells were intensely immunoreactive to glutamate, we decided to investigate whether glutamate might be such a transmitter, using two approaches. One approach was to make a quantitative immunogold analysis of ultrathin sections to assess the level of glutamate immunoreactivity of glomus cells relative to glia and to afferent axon terminals. The other approach was to measure the potassium-induced release of glutamate from carotid bodies superfused in vitro. We consistently found that glomus cell profiles had 50% more immunogold particles per unit of area than glial cell or axonal profiles. However, the levels of glutamate immunoreactivity of glomus cells were lower than those expected for glutamatergic terminals. We also found that glutamate was not released from in vitro carotid bodies stimulated with high concentrations of potassium. These findings indicate that the oxygen-sensitive glomus cells have a high concentration of glutamate, which is not released by superfusion with high potassium. Thus, glutamate is not the excitatory transmitter released by glomus cells. We speculate that the high concentrations of glutamate might instead be related to the known dependence of the “in vitro” chemosensory activity on metabolic substrates.     

Fine structure of dense-cored vesicles in glomus cells of rat carotid body after fixation with permanganate or glutaraldehyde.

Glomus (Type I) cells of the carotid body of adult rats were studied electron microscopically after fixation with potassium permanganate or with glutaraldehyde and osmium tetroxide. Two permanganate fixation methods (using Krebs-Ringer-glucose, pH 7.0, or acetate buffer, pH 5.0) were compared. Numerous dense-cored vesicles were observed only in about one tenth of the glomus cells when neutral permanganate was used for fixation, although all glomus cells showed such vesicles after fixation with glutaraldehyde and osmium tetroxide. Numerous vesicles with a dense core were observed in about one third of the cells after fixation with acid potassium permanganate. With this fixation, small dense-cored vesicles similar to those in adrenergic nerve terminals were occasionally seen in the cytoplasm of glomus cells. It is tentatively concluded that the amine-storing vesicles of the carotid body are different from those in the small intensely fluorescent (SIF) cells and those in adrenergic nerve terminals.     

Fine structure of dense-cored vesicles in glomus cells of rat carotid body after fixation with permanganate or glutaraldehyde

Summary Glomus (Type I) cells of the carotid body of adult rats were studied electron microscopically after fixation with potassium permanganate or with glutaraldehyde and osmium tetroxide. Two permanganate fixation methods (using Krebs-Ringer-glucose, pH 7.0, or acetate buffer, pH 5.0) were compared. Numerous dense-cored vesicles were observed only in about one tenth of the glomus cells when neutral permanganate was used for fixation, although all glomus cells showed such vesicles after fixation with glutaraldehyde and osmium tetroxide. Numerous vesicles with a dense core were observed in about one third of the cells after fixation with acid potassium permanganate. With this fixation, small dense-cored vesicles similar to those in adrenergic nerve terminals were occasionally seen in the cytoplasm of glomus cells. It is tentatively concluded that the amine-storing vesicles of the carotid body are different from those in the small intensely fluorescent (SIF) cells and those in adrenergic nerve terminals.     

The use of ultrasonography in preoperative localization of digital glomus tumors

Small glomus tumors of the digits of the hand are difficult to excise and may be associated with relatively high rates of recurrence. This study was designed to prospectively evaluate the utility of preoperative ultrasound localization of such tumors to facilitate removal and to reduce recurrence rates. During a 5-year period, 34 patients clinically diagnosed with glomus tumors involving their digits were examined with high-resolution ultrasonography (5 to 9 MHz). Color duplex sonography was further applied if flow characteristics were identified. The ultrasound-predicted and actual intraoperative sizes were correlated and analyzed using the paired t test. Patients were followed for 1 to 6 years, and results were documented. Sonography showed a hypoechoic nodule with prominent vascularity between the nail body and the dorsal cortex of the distal phalanx in all subungual tumors. Complete resection was possible in all 35 glomus tumors, with assistance by accurate preoperative ultrasound localization. There was no long-term recurrence among the 29 patients available for evaluation 1 to 6 years postoperatively. Ultrasonography has great advantages in defining the exact location and size of the glomus tumor preoperatively. Prior knowledge of the exact site and size of the glomus tumor facilitates excision and appears to reduce rates of recurrence. The collaboration between hand surgeons and radiologists is useful to successfully treat glomus tumors of the digit.     

Effect of acute hypoxia on glomus cell Em and psi m as measured by fluorescence imaging.

We have reinvestigated the hypothesis of the relative importance of glomus cell plasma and mitochondrial membrane potentials (E(m) and psi(m), respectively) in acute hypoxia by a noninvasive fluorescence microimaging technique using the voltage-sensitive dyes bis-oxonol and JC-1, respectively. Short-term (24 h)-cultured rat glomus cells and cultured PC-12 cells were used for the study. Glomus cell E(m) depolarization was indirectly confirmed by an increase in bis-oxonol (an anionic probe) fluorescence due to a graded increase in extracellular K(+). Fluorescence responses of glomus cell E(m) to acute hypoxia (approximately 10 Torr Po(2)) indicated depolarization in 20%, no response in 45%, and hyperpolarization in 35% of the cells tested, whereas all PC-12 cells consistently depolarized in response to hypoxia. Furthermore, glomus cell E(m) hyperpolarization was confirmed with high CO (approximately 500 Torr). Glomus cell psi(m) depolarization was indirectly assessed by a decrease in JC-1 (a cationic probe) fluorescence. Accordingly, 1 microM carbonyl cyanide p-trifluoromethoxyphenylhydrazone (an uncoupler of oxidative phosphorylation), high CO (a metabolic inhibitor), and acute hypoxia (approximately 10 Torr Po(2)) consistently depolarized the mitochondria in all glomus cells tested. Likewise, all PC-12 cell mitochondria depolarized in response to FCCP and hypoxia. Thus, although bis-oxonol could not show glomus cell depolarization consistently, JC-1 monitored glomus cell mitochondrial depolarization as an inevitable phenomenon in hypoxia. Overall, these responses supported our "metabomembrane hypothesis" of chemoreception.     

Granule matrix property and rapid "kiss-and-run" exocytosis contribute to the different kinetics of catecholamine release from carotid glomus and adrenal chromaffin cells at matched quantal size

Catecholamine-containing small dense core granules (SDCGs, vesicular diameter of ~100 nm) are prominent in carotid glomus (chemosensory) cells and some neurons, but the release kinetics from individual SDCGs has not been studied in detail. In this study, we compared the amperometric signals from glomus cells with those from adrenal chromaffin cells, which also secrete catecholamine but via large dense core granules (LDCGs, vesicular diameter of ~200-250 nm). When exocytosis was triggered by whole-cell dialysis (which raised the concentration of intracellular Ca(2+) ([Ca(2+)](i)) to ~0.5 μmol/L), the proportion of the type of signal that represents a flickering fusion pore was 9-fold higher for glomus cells. Yet, at the same range of quantal size (Q, the total amount of catecholamine that can be released from a granule), the kinetics of every phase of the amperometric spike signals from glomus cells was faster. Our data indicate that the last phenomenon involved at least 2 mechanisms: (i) the granule matrix of glomus cells can supply a higher concentration of free catecholamine during exocytosis; (ii) a modest elevation of [Ca(2+)](i) triggers a form of rapid "kiss-and-run" exocytosis, which is very prevalent among glomus SDCGs and leads to incomplete release of their catecholamine content (and underestimation of their Q value).     

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.     

The specification and growth factor inducibility of the pronephric glomus in Xenopus laevis

We report a study on the specification of the glomus, the filtration device of the amphibian pronephric kidney, using an explant culturing strategy in Xenopus laevis. Explants of presumptive pronephric mesoderm were dissected from embryos of mid-gastrula to swimming tadpole stages. These explants were cultured within ectodermal wraps and analysed by RT-PCR for the presence of the Wilm's Tumour-1 gene, xWT1, a marker specific for the glomus at the stages analysed, together with other mesodermal markers. We show that the glomus is specified at stage 12.5, the same stage at which pronephric tubules are specified. We have previously shown that pronephric duct is specified somewhat later, at stage 14. Furthermore, we have analysed the growth factor inducibility of the glomus in the presence or absence of retinoic acid (RA) by RT-PCR. We define for the first time the conditions under which these growth factors induce glomus tissue in animal cap tissue. Activin together with high concentrations of RA can induce glomus tissue from animal cap ectoderm. Unlike the pronephric tubules, the glomus can also be induced by FGF and RA.     

Expression of tandem P domain K+ channel, TREK-1, in the rat carotid body.

TREK-1 is one of the important potassium channels for regulating membrane excitability. To examine the distribution of TREK-1 in the rat carotid body, we performed RT-PCR for mRNA expression and in situ hybridization and immunohistochemistry for tissue distribution of TREK-1. RT-PCR detected mRNA expression of TREK-1 in the carotid body. Furthermore, in situ hybridization revealed the localization of TREK-1 mRNA in the glomus cells. TREK-1 immunoreactivity was mainly distributed in the glomus cells and nerve fibers in the carotid body. TREK-1 may modulate potassium current of glomus cells and/or afferent nerve endings in the rat carotid body.     

Ultrastructural changes in the rat carotid body in severe haemorrhagia

Summary Rat carotid bodies were studied electron microscopically after short-term severe hypovolaemia, which is known to induce a marked chemoreceptor activation in the carotid body. Altogether 84 nerve-endings in the hypovolaemic rats' carotid bodies and 91 nerve-endings in the control carotid bodies were investigated. An increased accumulation of the glomus cell granular vesicles near the synaptic specializations of the nerve-endings was observed after hypovolaemia. Moreover, a statistically significant increase in the contacts between the nerve-ending synaptic specializations and the glomus cell granular vesicles was observed after hypovolaemia. A suggestion was made that the glomus cells might act as modulating, probably inhibitory, interneurones, whose catecholamines are responsible for the inhibition.The authors are greatly indebted to lecturer Pekka Korkala Ph.L. from the Department of Psychology for his skilful statistical analysis of the results.     

Fine Needle Aspiration Cytology of Cutaneous Vascular Tumours

We have studied 12 cutaneous vascular tumours by means of fine-needle aspiration cytology (FNAC): six capillary haemangiomas, one cavernous haemangioma, one Masson's pseudo-angiosarcoma, two angiosarcomas, one benign haemangioendothelioma and one glomus tumour. We describe the main cytopathological findings and we discuss the differential diagnosis in each case. We consider that the cytopathological findings of the above lesions, evaluated in the context of the clinical findings, are sufficiently characteristic for us to be able to make a definitive diagnosis. We believe that FNAC can play an important part in the diagnosis and therapeutic planning of these tumours.     

Localization of acetylcholinesterase in dissociated cell cultures of the carotid body of the rat

Summary The localization of acetylcholinesterase (AChE) was investigated at the cellular and subcellular levels in dissociated cell cultures of the carotid body of the neonatal rat, prepared by the methods of Fishman and Schaffner (1984). In the presence of iso-OMPA, which blocks non-specific cholinesterase, staining was confined almost exclusively to glomus-cell clusters and occasional isolated cells. These clusters grow as discrete islands scattered throughout the culture and display typical catecholamine (CA) fluorescence as in vivo. AChE staining was abolished or reduced by the cholinesterase inhibitors eserine (30–100 M), or (the poorly lipid soluble) echothiophate (8 (M). Processing of the same culture sequentially for the demonstration of both AChE and CA revealed that glomus-cell clusters and individual glomus cells were consistently positive for both. In electron micrographs AChE reaction product was associated intracellularly with the nuclear envelope and cytoplasm of glomus cells (identified by their characteristic dense cored granules), as well as extracellularly with the boundaries of contiguous glomus cells. Significantly, reaction product occurred in some glomus cell profiles that had both dense-cored and clear (cholinergic-like) vesicles. These findings are discussed in the context of a possible dual (adrenergic/cholinergic) function status of glomus cells in the rat's carotid body.     

Immunohistochemical localization of tryptophan hydroxylase and serotonin transporter in the carotid body of the rat

It has been proposed that serotonin (5-HT) facilitates the chemosensory activity of the carotid body (CB). In the present study, we investigated mRNA expression and immunohistochemical localization of the 5-HT synthetic enzyme isoforms, tryptophan hydroxylase 1 (TPH1) and TPH2, and the 5-HT plasma membrane transport protein, 5-HT transporter (SERT), in the CB of the rat. RT-PCR analysis detected the expression of mRNA for TPH1 and SERT in extracts of the CB. Using immunohistochemistry, 5-HT immunoreactivity was observed in a few glomus cells. TPH1 and SERT immunoreactivities were observed in almost all glomus cells. SERT immunoreactivity was seen on nerve fibers with TPH1 immunoreactivity. SERT immunoreactivity was also observed in varicose nerve fibers immunoreactive for dopamine beta-hydroxylase, but not in nerve fibers immunoreactive for vesicular acetylcholine transporters or nerve terminals immunoreactive for P2X₃ purinoreceptors. These results suggest that 5-HT is synthesized and released from glomus cells and sympathetic nerve fibers in the CB of the rat, and that the chemosensory activity of the CB is regulated by 5-HT from glomus cells and sympathetic nerve fibers.     

The effects of 6-hydroxydopamine on the appearance of granulated vesicles in glomus cells of the rat carotid body

The glomus cells of the rat carotid body reveal an intense fluorescence after exposure to paraformaldehyde vapor and contain catecholamines. After initial fixation in glutaraldehyde, many granulated vesicles are seen in the glomus cells. After initial fixation in osmium tetroxide, most of the vesicles are depleted of their dense interiors and granulated vesicles occur infrequently. Administration of 6-hydroxydopamine followed by initial fixation in osmium tetroxide leads to the reappearance of dense interiors in virtually all vesicles. 6-Hydroxydopamine apparently is taken up by the membrane pump of the glomus cell and is incorporated into the amine storage granules, thereby displacing the endogenous monoamines. Osmium tetroxide does not dissolve the 6-hydroxydopamine from the vesicles, as it apparently does for the normal vesicular contents. The 6-hydroxydopamine does not fluoresce, hence 6-hydroxydopamine administration results in a decreased intensity of formaldehyde induced fluorescence in the glomus cells. Administration of reserpine after 6-hydroxydopamine treatment (and subsequent initial fixation in osmium tetroxide) depletes the previously restored dense material from the vesicles of the glomus cells. 6-Hydroxydopamine acts like a monoamine in that it is taken up by the glomus cell, incorporated into the vesicles, and can be depleted from the vesicles by reserpine.