Hierarchical somesthetic processing of tongue inputs in the postcentral somatosensory cortex of conscious macaque monkeys

The representation of the oral structures in the lateralmost part of the postcentral somatosensory cortex in conscious macaque monkeys was studied by recording the activities of single neurons. A total of 104 penetrations were made in the oral regions of six hemispheres in four animals and 2,292 neurons were isolated. The characteristics of the receptive fields (RF) of 1,598 neurons were identified. Of them, 513 neurons (area 3b, 196; area 1, 104; area 2, 213) along 44 penetrations responded to mechanical stimulation of the tongue (tongue neurons). The relative incidence of tongue neurons that had bilateral RFs increased gradually (bilateral integration) on moving caudally from area 3b to area 2. There was also a tendency for the RFs on the tongue to expand in the anteroposterior axis of the tongue (anteroposterior integration). Furthermore, the relative incidence of tongue neurons with composite RFs covering both the tongue and other surrounding oral structures was significantly higher in area 2 than in areas 3b and 1 (interstructural integration). As a result of the bilateral, anteroposterior and interstructural integration, the extent of the RFs of tongue neurons increased progressively from area 3b to area 2. We therefore concluded that hierarchical somatosensory processing, which has been established in the postcentral somatosensory cortex representing other body parts, is also present in the oral representation. We speculate that the hierarchical scheme in the oral representation might be a prerequisite neural process for the oral stereognosis that eventually takes place in the association cortices. Electronic Publication     

Postcentral neurons with covert receptive fields in conscious macaque monkeys: their selective responsiveness to simultaneous two-point stimuli applied to discrete oral portions

The representation of the oral structures in the postcentral somatosensory cortex was studied in conscious macaque monkeys by recording the activity of single neurons. A total of 2,807 neurons were isolated in the oral regions of three hemispheres in two animals. Of these, 375 neurons (area 3a, 3; area 3b, 123; area 1, 99; area 2, 150) lacked an apparent receptive field (RF), and their relative frequency was significantly higher in area 2 (19%) than in more rostral areas (area 3a, 8%; area 3b, 10%; area 1, 12%). We tested the responsiveness of these neurons to stimuli applied simultaneously to two discrete, but functionally related, oral structures (interstructural two-point stimuli: iTPS). Neurons in areas 3a, 3b, and 1 that lacked an apparent RF were not responsive to iTPS. However, 35 neurons in area 2 responded stably to iTPS applied to either of the following sets of oral structures: the tongue and incisors (n=18), incisors and lip (n=9), lip and tongue (n=12), or upper and lower lips (n=8). Of them, 19 neurons were activated during self-movements such as tongue protrusion, lip licking, and food manipulation. The neurons selectively responsive to iTPS might detect converging inputs from different oral structures and play a pivotal role in detecting objects straddling different oral structures and the mutual contact of oral structures.     

The taste and mechanical response properties of neurons in the parvicellular part of the thalamic posteromedial ventral nucleus of the rat

A total of 41 taste and 17 mechanoreceptive neurons were recorded in the parvicellular part of the posteromedial ventral nucleus of the thalamus (VPMpc) of amobarbital-anesthetized rats. Most of the taste neurons were located in the rostral part, while most of the mechanoreceptive neurons were located in the middle part of the VPMpc. Stimulation of the whole oral cavity with four basic taste stimuli produced smaller mean response magnitudes in these thalamic taste neurons than in the parabrachio-thalamic (P-T) taste relay neurons. Receptive fields (RFs) for most of the 21 taste neurons examined were located on the tongue or on the tongue and palate, as with P-T relay neurons. Some neurons had RFs ipsilaterally in the oral cavity, as do P-T relay neurons; but others had RFs contralaterally or bilaterally. Several neurons had large RFs in comparison with those of P-T relay neurons. A majority of the thalamic taste neurons were also mechanosensitive, and their RFs were larger for mechanical stimulation than for taste stimulation. Many (12/17) of the mechanoreceptive neurons had a low response threshold, activated by stroking the tissue with a glass rod; and others had a high response threshold, activated by a pinch with a pair of non-serrated forceps. Their RFs were contralaterally or bilaterally located on either the tongue, or palate or on both regions. One taste neuron and some mechanoreceptive neurons were also excited by mechanical stimulation on the cheek or lip. These observations may represent integrative processes for taste and mechanical oral information at the thalamic level.     

Bilateral receptive field neurons in the hindlimb region of the postcentral somatosensory cortex in awake macaque monkeys

Single-neuron activities were recorded in the hindlimb region of the primary somatosensory cortex and part of area 5 in awake Japanese monkeys. A total of 1050 units were isolated from five hemispheres of four animals. Receptive fields (RFs) and submodalities were identified for 90% of isolated neurons in areas 3a and 3b. The percentage decreased as the recoding site moved to the more caudal areas. Deep or skin submodality neurons were dominant in area 3a or area 3b, respectively. Deep submodality neurons increased in more caudal areas and were the majority in areas 2 and 5. These observations were consistent with those in the hand and/or digit or arm and/or trunk region. The identified neurons were classified by their RF positions into four types: the foot, leg, foot and leg, or hindlimb and other body parts type. Among 831 identified neurons, 33 neurons had bilateral RFs, 14 had ipsilateral RFs, and the rest (N=784) had contralateral RFs. The relative incidence of neurons with bilateral or ipsilateral RFs among identified neurons was less than 1% in areas 3a, 3b, and 1, and 16% or 25% in areas 2 or 5, respectively. Within areas 2 and 5, the percentage of neurons with bilateral or ipsilateral RFs was significantly smaller in the foot type (5%) than in other RF types (24-57%). RFs of the foot type were on the sole or single toe but never on multiple toes. These observations contrasted with the previous findings that neurons with bilateral RFs were more frequently seen in the hand and/or digit region and that RFs on multiple digit tips were dominant there. The present study thus demonstrated that neurons with bilateral RFs do exist in the hindlimb region. Similarly to the forelimb region, they were found mostly in areas 2 and 5, the caudalmost areas of the postcentral gyrus and hierarchically higher stages in information processing. The relative paucity of neurons with bilateral RFs on the foot, especially those with RFs on multiple toes, may reflect functional differences between the foot and the hand.     

Representation of the midline trunk, bilateral arms, and shoulders in the monkey postcentral somatosensory cortex

 Single neuronal activities were recorded in the arm/trunk region of the postcentral gyrus in awake Japanese monkeys. A total of 1608 units were isolated from four hemispheres of two animals, and receptive fields (RFs) and submodalities were identified in 1162 units. Deep or skin submodality neurons were dominant in area 3a or area 3b, respectively. The deep/skin ratio increased as the recording site moved from area 3b to the more caudal areas. In areas 3a and 3b, neuronal RFs were almost exclusively on either the arm or trunk. In areas 2 and 5, neurons with RFs on the trunk decreased and those with RFs on the hand or covering more than one body part, etc. increased. We found a total of 107 neurons with bilateral RFs and 56 with ipsilateral RFs, while the rest (n=999) were with contralateral RFs. Bilateral or ipsilateral neurons of skin submodality (n=37) were found in areas 1, 2, and 5. Twenty six (70%) had RFs on the trunk and/or occiput, five on the forelimb, and the rest (n=6) on both the trunk and forelimb (the combined type). Among 33 skin bilateral neurons, 90% (n=30) had RFs across the midline. Bilateral or ipsilateral neurons responding to joint manipulation (n=104) were found in areas 2 and 5. Most of them were activated by manipulation of the shoulder and/or elbow (the proximal type, n=72, 69%). There were 25 neurons of the combined type (both the proximal and distal joints were effective, 24%). Bilateral or ipsilateral neurons of deep-others submodality (n=20) were found in areas 1, 2, and 5. The forelimb type (n=12, 60%) was dominant in this category. The combined-type neurons in both the skin- and joint-manipulation categories were found only or mostly in area 5. These results indicate the presence of hierarchical processing for bilateral as well as contralateral information within the arm/trunk region of the postcentral gyrus. Received: 12 January 1998 / Accepted: 19 May 1998     

Receptive fields of solitario-parabrachial relay neurons responsive to natural stimulation of the oral cavity in rats

Summary The receptive field (RF) of 67 taste and 85 mechanoreceptive neurons in the solitary tract nucleus (NTS) were located in the oral cavity in albino rats. All of the taste and most (62.4%) of the mechanoreceptive neurons examined had an RF on the ipsilateral side of the tongue and/or the palate. Regardless of whether they were solitario-parabrachial relay (SP) neurons or non-SP neurons, RFs of taste neurons were found on the anterior as well as the posterior tongue. But there were some differences in the RF distribution between the SP and non-SP mechanoreceptive neurons. Most of the mechanoreceptive SP neurons (9 of 11) had an RF on the tongue, while ca. half of the mechanoreceptive non-SP neurons (43 of 79) had an RF on the tongue and palate, but the rest had an RF on other tissue. Most of the neurons studied had a small restricted RF, but complex RFs, e.g. two separate RFs on the tongue, were found in a relatively small number of neurons (four taste and five mechanoreceptive neurons). An inhibitory RF, usually in a remote place from the excitatory RFs, was found in four mechanoreceptive neurons but no inhibitory RFs for taste neurons. Electrical stimulation of the epithelium in the RF with a low current of short duration evoked a few spikes in most units. Two of the three units, giving rise to a vigorous response to taste stimulation, but having single restricted RFs on the anterior tongue, produced a train of spikes lasting more than 20 ms in response to electrical stimulation of the RF. Neurons with RFs on the anterior tongue and those with RFs on the posterior tongue were located in different regions in the NTS, suggesting a possible somatotopic representation of the oral cavity in the nucleus. RFs of neither taste neurons nor mechanoreceptive neurons could be found in the tongue region containing the circumvallate papilla. The possible reasons are discussed.Supported by a Grant from the Ministry of Education, Science and Culture of Japan (No. 58106008)     

Convergence of input from tongue and palate to the parabrachial nucleus neurons of rats

Receptive fields (RFs) in the oral cavity were examined for 24 taste and 20 mechanoreceptive neurons in the parabrachial nucleus (PB) of anesthetized rats. All of the units studied had an RF on the ipsilateral half of the oral cavity. About half of the units in each category had at least two separate RFs. Most of the ‘taste neurons’, i.e. units receiving taste inputs, were activated by mechanical stimulation and some of them had a complex RF, e.g. separated into two parts, one on the tongue for taste and one on the palate for mechanical stimulation. The present findings show that the afferent inputs of two modalities from the tongue and palate converge on the PB neurons.     

Rostrocaudal gradients in the neuronal receptive field complexity in the finger region of the alert monkey's postcentral gyrus

Summary In the primate postcentral gyrus, the cytoarchitectonic characteristics gradually shift from those of koniocortex to more homotypical parakoniocortex along its rostrocaudal axis. To find the physiological correlates of these changes we examined a large body of data accumulated during a series of our experiments with alert monkeys. Along the rostrocaudal axis of the postcentral gyrus, we found a gradual and continuous increase in the number of neurons with converging receptive fields and those in which receptive field positions or submodalities were not determined. Deep or skin submodality neurons were dominant in area 3a or 3b respectively. The proportion of skin submodality neurons decreased gradually from area 3b to the more caudal part of the gyrus. The proportion of deep submodality neurons was almost constant from area 3b to area 2 inclusive; they were not the majority in area 2. The data are consistent with the hierarchical scheme, i.e., within the postcentral gyrus sensory information is processed from the primary sensory receiving stage to the more associative, integrative stages.     

Receptive field properties of the parabrachio-thalamic taste and mechanoreceptive neurons in rats

Summary Receptive fields (RFs) of 36 taste (the 22 parabrachio-thalamic relay (P-T) and 14 non-P-T) and 23 mechanoreceptive neurons (7 P-T and 16 non P-T) were located in the oral cavity of rats. All of the taste and most of the mechanoreceptive units examined had an RF on the ipsilateral side of the tongue or palate, but some mechanoreceptive P-T and non-P-T units had RFs bilaterally. When the RFs of taste neurons were examined with the most effective of the four basic taste (the best stimulus) and non-best stimuli, no difference was noticed in the location of RFs between the P-T and non-P-T neurons. Though most of the P-T neurons (7/11) and all of the non-P-T neurons (6/6) had an RF for non-best stimuli at a region similar to that for the best stimulus, some P-T neurons (4/11) had an RFs for non-best stimulus outside the RF for the best stimulus and/or on the region separate from the RF for the best stimulus. The P-T neurons, responding vigorously to non-optimal stimuli as well as to the best stimulus, had an RF outside the RF for the best stimulus. RFs for mechanical stimulation were also examined in some taste and mechanoreceptive neurons. The mechanoreceptive P-T units rarely had an RF exclusively on the palate. Some mechanoreceptive units had an RF on the region where no taste RF has been found, e.g. the intermolar eminence and the folium of the hard palate.     

Oral cavity representation at the frontal operculum of macaque monkeys

Receptive properties of neurons at areas 3 and 1-2, and the gustatory area (area G) in the frontal operculum (Fop) and the neighboring areas were investigated in the cerebral cortex of Macaca irus and Macaca fuscata by applying mechanical and taste stimulation to the oral cavity and lips. Tactile neurons with different receptive properties were noted in areas 3, 1-2 and G. Areas 3 and G were packed with tongue neurons, though a considerable number of palate neurons were also found in area G, while area 1-2 was involved in representation of the tongue, palate, periodontia and lips. Both the anterior and posterior parts of the tongue were represented on these areas, and of the palate, the posterior part (the soft palate) was largely represented. The anterior and posterior periodontia were represented, without separation. Various tissues were represented with different laterality: Periodontia and the lips were most frequently represented bilaterally or contralaterally, but the tongue and palate often ipsilaterally. In area 6, the insula and other areas surrounding areas 3, 1-2 and G, tactile neurons were also found to have receptive fields on the lips, tongue, palate or periodontium, and the receptive fields on the tongue or palate were mainly bilateral. On the other hand, most of the taste neurons were located in area G and some in area 1-2 and the insula. The present study demonstrated that in macaque monkeys, tactile sensation of the oral cavity is represented on areas 3, 1-2 and G in the Fop as well as on the surrounding areas (e.g., area 6 and the insula), and taste sensation on areas G and 1-2 and the insula.     

Cytokeratin expression in pseudoepitheliomatous hyperplasia of oral paracoccidioidomycosis.

Paracoccidioidomycosis (Pmycosis) is one the most prevalent deep systemic mycoses in Latin America. It is characterized by granulomatous inflammation and pseudoepitheliomatous hyperplasia. Cytokeratins (CKs) are a group of intermediate filaments of epithelial cells and their expression varies according to the epithelium type, differentiation and pathological processes. This study describes cytokeratin expression as examined by immunohistochemistry, in 28 cases of oral Pmycosis involving the buccal mucosa, lip, gingiva and hard palate. Expression of CKs in the basal layer of the epithelium in pseudoepitheliomatous hyperplasia of Pmycosis was similar to that in normal oral mucosa (NOM), but in Pmycosis CK1 and CK10 were not expressed in the spinous and superficial layers of the lip, gingiva or hard palate, and, in the spinous and superficial layers of the lip and buccal mucosa, CK14 was positive in contrast to NOM where it was negative. In Pmycosis, CK6 was more frequently expressed in the spinous layer of the lip, gingiva and hard palate, but nevertheless CK16 expression was decreased in the spinous and superficial layers of the gingiva and hard palate. We conclude that pseudoepitheliomatous hyperplasia in oral Pmycosis shows a different pattern of CK expression, particularly CKs 1, 10 and 14, compared with NOM.     

Columnar organization of mechanoreceptive neurons in the cortical taste area in the rat

Mechanoreceptive neurons with or without taste responsiveness were recorded in the cortical taste area (CTA) of rats every 50 or 100 μm along an electrode track made as perpendicular to the surface as possible. Three groups of mechanoreceptive neurons were recognized based on the adequate stimulus, i.e., low-threshold mechanoreceptive (n=16), nociceptive-specific (n=48), and wide-dynamic range neurons (n=392). Except for nine neurons, almost all had receptive fields (RFs) in the oral cavity (n=447). They were categorized into three RF types: those with RFs only in the oral cavity (OC type; n=23), those with RFs both in the oral cavity and on the lip (OL type; n=44) and those with RFs in the oral cavity and on the external surface of the body (WB type; n=380), e.g., tail. Neurons with inhibitory RFs were often located in the infragranular layers. Several neurons with the same receptive features were sequentially recorded along the track, suggesting the presence of columnar organization. The diameter of the possible functional column was the largest (mean 113.85 μm) for WB type neurons, but smaller in the other two types (mean 85 μm for the OC type and 62.5 μm for the OL type). Neurons were segregated according to the adequate stimulus within the column for WB type neurons. Taste-responsive mechanoreceptive neurons (n=33) were recorded at 15 tracks, and two taste neurons were sequentially recorded in five cases, in three of which two successive neurons sharing the best stimulus were recorded. Taste neurons are possibly arranged in a column with a very small diameter within the large column of mechanoreceptive neurons. Electronic Publication     

Difference in receptive field features of taste neurons in rat granular and dysgranular insular cortices

Summary Receptive fields (RFs) of 59 cortical taste neurons (35 in the granular insular area, area GI, 21 in the dysgranular insular area, area DI, and 3 in the agranular insular area, area AI) were identified in the oral cavity of the rat. The fraction of the neurons with RFs in the anterior oral cavity only was significantly larger in area GI (74.3%) than in area DI (42.9%). On the other hand, the fraction of neurons with RFs in both the anterior and posterior oral cavity was larger in area DI (42.9%) than in area GI (11.4%). On the whole, it is suggested that area GI is involved in discrimination of several taste stimuli in the oral cavity, whereas in area DI taste information originating from various regions of the oral cavity is integrated. When neurons were classified according to the best stimulus which most excited the neuron among the four basic tastes, different categories of taste neurons had RFs in different parts of the oral cavity. It is suggested that, in either taste area, different categories of taste neurons are involved in different sorts of taste coding. The majority of neurons in both areas had bilateral RFs. In area GI, neurons with RFs on single subpopulations of taste buds were significantly more numerous at the rostral region of the cortex than at the caudal region. There was no such relation between RF types and cortical localization in area DI. Otherwise, topographic representation of the oral cavity by taste neurons on the cortical surface was not obvious. RF features of taste neurons did not differ across layers in either cortical area.     

Receptive field properties of thalamo-cortical taste relay neurons in the parvicellular part of the posteromedial ventral nucleus in rats

Summary Twenty-five taste and 35 mechanoreceptive neurons were recorded from the parvicellular part of the posteromedial ventral nucleus (VPMpc) in rats. Among them, 14 (56%) of the taste and 7 (18.4%) of the mechanoreceptive neurons were antidromically activated from the cortical taste area (CTA) with a latency of 1–4 ms and identified as thalamocortical (TC) relay neurons. No significant differences were evident in the receptive field properties or in the location in the VPMpc between the TC and non-TC neuron groups. Two classes of TC neurons were recognized: one class consisted of neurons which were most excited by NaCl among the four basic taste stimuli with receptive fields (RFs) confined to a part of the oral cavity, e.g. the anterior tongue, and the other class contained neurons which were most excited by sucrose or HCl, with RFs over a wide area of the oral cavity. Both the TC and non-TC neurons showed similar effects of CTA stimulation: post-stimulus time histograms revealed a long lasting inhibition followed by a rebound facilitation of spontaneous discharge.     

经手术和语音康复后非综合征型唇腭裂儿童静息态脑功能改变的磁共振特征

目的：探讨非综合征型唇腭裂（NSCLP）患儿在外科修复术和语音治疗康复后静息状态脑功能模式。方法：选取北京儿童医院和北京口腔医院就诊的28例NSCLP儿童和28例性别和年龄相匹配的健康者（对照组）,进行3DT1和静息态功能性磁共振数据采集。使用DPARSFA软件进行预处理并计算低频振幅（ALFF）和局部一致性（ReHo）,采用双样本t检验评价组间差异（TFCE校正, P<0.05）。对于有显著性差异脑区的静息态脑功能参数与汉语语言清晰度量表（CLCDS）评分进行相关性分析。结果：NSCLP患儿左颞中回、左枕中回、右楔叶、右楔前叶、左中央后回、左顶上小叶ALFF值明显降低。与对照组相比,ReHo值降低脑区包括左侧的中央后回、中央前回、顶上小叶、缘上回和旁中央小叶。异常脑区的ALFF值和ReHo值与CLCDS评分无显著性相关。结论：经外科修复手术和语音治疗康复后的NSCLP患儿静息态自发性神经元活动及其协调性仍未达到正常水平,且以优势半球的语言相关脑区异常为主。     

Neuromagnetic studies of the lip area of primary somatosensory cortex in humans: evidence for an oscillotopic organization

Magnetic trigeminal somatosensory responses from human subjects were recorded using a 14-channel magnetoencephalographic system. Sensory stimuli comprising a 15-ms vibration at frequencies of 50 Hz, 150 Hz and 250 Hz were given at randomized interstimulus intervals. Using a single dipole model, the neuronal sources of the evoked responses were determined, and mapped onto magnetic resonance images of each subject. Source localization analysis was based on the main peak of the averaged signal (M55). All of the sources were located deep in the anterior bank of the postcentral gyrus, corresponding to area 3b of somatosensory cortex SI. In all cases, the source for the upper lip was significantly higher in the vertical axis (0.6–1.1 cm) than for the lower lip, while the lower lip stimulation produced a larger response than the upper lip. Furthermore, statistically significant differences were found between the locations of the dipoles evoked by different frequency stimulation. The location of the response shifted with change in stimulation frequency, showing a trend among all subjects with a medial shift between 150 and 250 Hz for both upper and lower lip. The accuracy of source localization calculated from magnetic fields ranged between ±0.9 and ±3.0 mm (SEM). These results demonstrate (1) that a large area of the somatosensory cortex is utilized for lip representation and (2) that the spatial displacement of the trigeminal somatosensory response may be related to the discrimination of frequency.     

Neurons with large bilateral receptive fields in monkey prelunate gyrus

In single-cell recordings from the dorsocaudal part of the prelunate gyrus of an alert monkey (Macaca fascicularis) we found neurons with unexpectedly large receptive fields (RFs) that spread bilaterally into the contra- and ipsilateral visual fields. These neurons (n=82) appeared to be clustered in the periphery of V4. They were surrounded by neurons with relatively small (3-10 degrees) and unilateral RFs in the contralateral field with properties similar to those previously described for neurons in area V4. Bilateral RFs extended over large parts of the lower visual field but always spared the fovea. Receptive fields typically revealed two foci of maximal responsiveness that were arranged symmetrically in the ipsi- and contralateral fields. Twenty-six cells did not respond to stimuli along the vertical meridian; these neurons had two distinct RFs. The preference for stimulus orientation, color, or motion was similar in all parts of these large RFs.     

人大脑半球顶叶外侧面隆凸形态

目的 探讨人大脑半球顶叶外侧面的脑回形态。 方法 肉眼观察、游标卡尺测量60例（120侧）福尔马林固定人脑顶叶脑回。结果 顶叶
外侧面可见恒定的隆凸，定位于中央后回中、下1/3交界处后方，面积在2cm×2cm至4.5cm×4.5cm的范围；体表投影在耳廓上端上方稍后约3cm处。
主要由缘上回组成，该脑回呈多种形态，或呈弧形突向后上方，或为短脑回突入外侧沟末端，或同时突向后上方和前下方(外侧沟末端)等。当隆
凸明显时，中央前、后回下部被推向前方稍弯，上部相对向后，整体呈s形。〖HTH〗 结论 大脑半球顶叶外侧面存在一个恒定由缘上回为主构成
的隆凸，可从颅、内外进行定位。     

Origins of parasympathetic postganglionic vasodilator fibers supplying the lips and gingivae; an WGA-HRP study in the cat.

Application of WGA-HRP to the mandibular lip and buccal gingiva of the cat resulted in retrograde labeling in the ipsilateral otic ganglion (OG), whereas labeled neurons appeared in the pterygopalatine ganglion (PPG) as well as in the OG when the tracer was injected into the maxillary lip and buccal gingiva. The results suggest that both the facial and the glossopharyngeal preganglionic vasodilator fibers supplying the mandibular lip and buccal gingiva mediated in the OG, and those innervating the maxillary lip and buccal gingiva are mediated in the PPG and the OG.     

Oral and salivary gland angiosarcoma: a clinicopathologic study of 29 cases.

Angiosarcomas of the oral and salivary gland area are extremely rare, mostly presented as case reports. We wanted to study the clinicopathologic features of a series of oral and salivary gland angiosarcomas. Cases coded as "angiosarcoma" were retrieved from the Oral and Maxillofacial Pathology Department of the Armed Forces Institute of Pathology. Patient folders and pathology were reviewed and recorded; immunohistochemistry and follow-up were obtained. Inclusion required oral or salivary gland location, vasoformative growth, cytologic atypia, mitoses, and vascular markers. Skin, bone, and subcutaneous angiosarcomas were excluded. Primary and secondary (metastatic) oral angiosarcomas were included. The 22 primary angiosarcomas involved tongue (n = 9), parotid (n = 4), lip (n = 4), submandibular gland (n = 3), and 1 each of soft and hard palate. The 7 secondary angiosarcomas involved the gingiva (n = 4) and parotid gland (n = 3). Overall, patient ages ranged from 6-90 years (mean, 55 years). There were 15 males and 14 females. Symptoms included a mass with recent enlargement and bleeding. Tumor sizes ranged from 0.8-7.0 cm (mean, 2.6 cm). Histologically, all tumors were vasoformative; 86% had solid and 17% had distinctive papillary areas. Eight (28%) were classified as the epithelioid subtype. Immunohistochemical stains showed that the tumor cells were positive for Factor VIIIrag in 19/21, CD31 in 16/19, CD34 in 7/12, and Ulex in 1/1. Primary tumors were classified as low grade (n = 7, in all locations except salivary gland), intermediate (n = 7), and high grade (n = 8); all secondary tumors were high grade. Follow-up was available on 14/22 primary and 7/7 secondary angiosarcomas. Of primary tumors, two tongue angiosarcoma patients died at 1 and 9 years, but 4 were alive without disease over a mean of 7.3 years (range, 1-13 years). Four primary salivary gland angiosarcoma patients were alive without disease over a mean of 5.8 years (range, 1-14 years), and 1 had only a late (15 years) metastasis and death (at 20 years). Three primary lip angiosarcoma patients were without disease over a mean of 14.3 years (range, 13-16 years). Of secondary tumors, three salivary gland angiosarcoma patients died within 1 year, and all four secondary gingival angiosarcoma patients died of disease within 3 years. Assessing follow-up of primary oral and salivary gland angiosarcoma patients by grade, 5 patients with high-grade tumors had no evidence of disease over a mean of 7.6 years (range, 1-16 years), 3 patients with intermediate-grade tumors had no evidence of disease over a mean of 12.7 years (range, 11-14 years), 2 patients with intermediate-grade tumors died of disease at 9 and 20 years, 3 patients with low-grade tumors had no evidence of disease over a mean of 6.3 years (range, 1-14 years), and 1 patient with low-grade tumor died of disease at 1 year. Primary oral and salivary gland angiosarcomas, albeit rare, mostly involve the tongue, parotid gland, and lip of adults, often with relatively good outcome. Although the most common angiosarcoma morphology in this area is spindled vasoformative and solid, almost one third of oral and salivary gland angiosarcomas are the rare epithelioid angiosarcoma variant. Most gingival and few parotid angiosarcomas appear to be metastases from other locations, with many patients succumbing to death within 3 years. Despite predominantly high- or intermediate-grade morphology, patients with primary angiosarcoma of the tongue, salivary gland, and lip have a better prognosis than do patients with primary cutaneous or deep soft tissue angiosarcoma, including those patients with secondary oral and salivary gland involvement.