We reviewed biopsy records for 37 cases of oral histoplasmosis for patient characteristics, clinical features, and histopathologic findings. These represented cases diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur between July 1967 and October 1994. All were male patients who ranged in age from 11 to 79 years (mean age, 56.7 years). There were 40.6% Malays, 37.8% Chinese, 18.9% Indians, and 2.7% other races. Five patients with mouth lesions as the initial presenting lesions were proven to be cases of disseminated histoplasmosis. In the remaining cases apart from the biopsy-proven oral histoplasmosis lesions, the extent of the disease elsewhere was unknown. The majority of these lesions involved the gingiva, tongue, and palate in decreasing order of frequency. The most frequent presenting symptom was oral mucosal ulceration. Squamous cell carcinoma and tuberculosis were the two most common clinical differential diagnoses. Our present findings compare favorably with published reports from other regions.
Seventeen cases are reported of desmoplastic variant of ameloblastoma of the jaws observed during the years 1967-1991. There were 12 females and 5 males, and these consisted of 7 Chinese, 6 Malays, 2 Indians, 1 Sikh and 1 Kadazan. Their ages at diagnosis ranged from 21-60 years with a mean of 36.6 years. There were 10 mandibular and 7 maxillary tumours. Of these, 14 cases involved the anterior segment with extension to the premolar region in 5 cases. 60% of cases were radiologically suggestive of fibro-osseous lesions. The main mode of treatment was resection and 1 case presented with recurrence. The findings of this study were compared with those of previous reports.
Four cases of either combined occurrence of ameloblastoma and odontogenic keratocyst or a rare keratinising variant of ameloblastoma are presented. The cardinal histomorphologic characteristics are simultaneous occurrence of ameloblastomatous epithelial islands with central keratinisation and multiple keratinising cysts. Immunohistochemically the tumour elements were keratin positive and occasionally S-100 protein and desmin positive. Major differential diagnosis of these neoplasms are discussed.
Granular cell ameloblastoma (GCA) is a well recognized variant of follicular ameloblastoma with extensive granular cell change. In contrast, plexiform granular cell odontogenic tumor (PGCOT) is a rare and recently described lesion characterized histologically by a monophasic plexiform pattern of granular cells. In this paper, two cases of an unusual granular cell odontogenic tumor exhibiting combined features of these two entities are described along with their immunohistochemical characteristics. The granular cells of both the GCA and PGCOT areas showed similar patterns of expression for keratin and S-100, which differed from those of typical ameloblastoma. No reactivity for desmin or vimentin was noted. The histomorphologic and immunohistochemical features of these hybrid tumors suggest that the granular cells present have a common origin, most probably the odontogenic epithelium.
Seventeen cases of desmoplastic ameloblastoma were examined immunohistochemically. Immunoperoxidase techniques were applied for detection of keratin, desmin, vimentin and S-100 protein expression in these tumors. The tumor epithelium of desmoplastic ameloblastoma exhibited weak, focal, inconstant keratin staining, weak, variable expression of S-100 protein, desmin immunoreactivity of mild to moderate intensity and vimentin non-reactivity. The pertinent literature on the immunohistochemistry of ameloblastomas is briefly reviewed.
Four hundred and one cases of ameloblastoma of the jaw diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, between 1967 and 1991 have been analysed. There were 214 males and 187 females. Of these, 50.1% were Malays, 34.7% Chinese, 8.2% Indians and 7.0% other races. Seventy-two percent of patients were in the second, third and fourth decades of life (mean age: 30.8 years). Ninety-three percent of tumours occurred in the mandible and 6.5% in the maxilla. There were 337 cases of conventional ameloblastoma, 49 cases of the unicystic variant and four cases of peripheral ameloblastoma. The predominant histologic patterns were plexiform (34.2%), follicular (16.5%) and mixture of both (17.7%). Majority of the cases were conservatively treated by enucleation. Fifty-nine cases presented with recurrences. Present findings were generally compatible with regional serial studies reported from Thailand, Singapore and Japan.
The clinical and histological features of the peripheral odontogenic fibroma are briefly outlined. A case arising from the attached lingual gingiva between the mandibular right permanent first molar and the second molar in a 67 year old Indian female is reported here. The unusual occurrence of marked clear cell differentiation within the odontogenic epithelial component, and histogenetic link to the clear cell rests of the dental lamina and surface epithelium are discussed.
A case is described of ameloblastoma of the mandible presenting with multiple recurrences and subsequent extension to the maxilla with resultant transformation into an aggressive (malignant?) epithelial odontogenic ghost cell tumour. The latter is a rare, biologically virulent entity that affects mainly males, exhibits a preference for the maxilla and is histologically characterized by atypical malignant odontogenic epithelium associated with areas of ghost cell formation and varying amounts of dentinoid.
This report reviews the clinicopathologic characteristics of 104 cases of odontomas diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period (1967-1995). The results showed no real predilection in terms of sex (M:F ratio, 1:1), race (45.2% Malays, 40.4% Chinese, 10.6% Indians and 3.8% other races) or site (maxilla:mandible ratio, 1: 1.04) distribution. The mean age at presentation was 24.8 years and the age range was 3-74 years. There were 102 intraosseous and 2 extraosseous odontomas. Swelling was the most common presenting complaint. The majority of cases (81.9%) were clinically diagnosed as odontomas. The treatment of choice was surgical enucleation. Compound (43.3%) and complex (35.5%) odontomas were the two most common histological types encountered. The present findings correlate favorably with reported studies from other geographic areas.
We reviewed the clinicopathological characteristics of 13 cases of calcifying epithelial odontogenic tumour (CEOT) (Pindborg tumour) diagnosed in the Division on Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period. There were eight female and five male patients. These consisted of eight (61.5 per cent) Malays, three (23.1 per cent) Chinese, one (7.7 per cent) Indian and one (7.7 per cent) Melanau. Their ages at presentation ranged from 19-61 years (mean age, 31.8 years). There were 12 central and one peripheral CEOT. Of these, 76.9 per cent of cases were located in the maxilla, the remaining in the mandible. The commonest clinical diagnosis was a dentigerous cyst (66.7 per cent). Enucleation was the main mode of treatment. Histologically, sheets and strands of polyhedral epithelial cells containing eosinophilic, homogeneous globules with Liesegang rings were observed. One case also showed extensive calcification and clear cell differentiation. Immunohistochemistry revealed a variable keratin staining of the CEOT epithelium, confirming its heterogeneity.
Twelve pleomorphic adenomas of minor salivary gland origin were examined for the distribution of S-100 protein, detected using the peroxidase-antiperoxidase (PAP) method. Strong S-100 protein immunoreactivity was noted in areas containing plasmacytoid cells, stellate and spindle cells against a myxochondroid or hyalinous stroma, and solid epithelial areas. Tubular and duct-like structures showed variable stainability. Stromal tissue and normal salivary glands were generally negative for S-100 protein. These findings were compared with those reported elsewhere.
The records of the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, Malaysia, were reviewed for the incidence of odontogenic keratocysts of the orthokeratinised variety, during the 20-year-period, 1967 to 1986. Nine cases were found. The clinical, histological and radiological features of these cases are reported. Many features were similar to previous reports of this entity but a peak incidence in the second decade of life, an almost even distribution in the maxilla and mandible, and a distinct predilection for the Chinese were observed. It is suggested that these features may be peculiar to Malaysians.
The combined epithelial odontogenic tumour represents a hybrid lesion comprising primarily areas of adenomatoid odontogenic tumour intermixed with foci of calcifying epithelial odontogenic tumour. Five such cases retrieved from the files of the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, and four others from the existing literature were analysed. A mean age of 18.8 years, a female preponderance (66.7%) with a male to female ratio of 1:2 and predilection for the mandible (55.6%) were observed. All cases were treated by conservative surgery and the lack of recurrence confirmed the innocuous nature of this lesion.
This report details a case of mandibular peripheral ameloblastoma having a clear cell component. The latter consisted of ovoid cells with vacuolated or clear cytoplasm and vesicular or pyknotic nuclei that may be disposed as discrete clusters or show direct transition from typical acanthomatous areas. Comparison of this lesion with other odontogenic and nonodontogenic tumors that contain clear cells is discussed in the context of the differential diagnosis.
Mucoepidermoid tumours of the minor salivary glands of the tongue are rarely encountered. A case of a high-grade malignant type is reported here. Merits of subdivision of the mucoepidermoid tumour on the basis of its malignant potential are outlined, and variations of histological presentation of the present tumour at its primary and nodal sites are discussed.
We investigated microwave-stimulated fixation of tissues for transmission electron microscopy using a domestic microwave oven operating at a frequency of 2.45 GHz with an output power of 500W. Microwave-stimulated fixation, in 4% glutaraldehyde, of fresh rat kidney, liver, heart and brain tissues was compared to conventional fixation. Human renal biopsies were similarly studied. Electron microscopy showed excellent ultrastructural preservation comparable to that obtained by conventional fixation. The optimal temperature range for microwave-stimulated fixation was found to lie between 50 degrees C and 55 degrees C. Our results indicate that microwave-stimulated fixation is a rapid and reproducible technique and can be effectively applied to routine diagnostic pathology.
A case is described of ameloblastoma of maxilla presenting with numerous calcified keratin pearls. The significance of cellular variation in relation to the behavioural potential of the ameloblastoma in general is briefly discussed.
The morphology, incidence and distribution of hyaline cells in ten cases each of pleomorphic adenoma, adenoid cystic carcinoma, adenocarcinoma and mucoepidermoid tumour were studied by conventional light microscopy. Results showed that the hyaline cells were identified in 60% of pleomorphic adenoma and in 20% of mucoepidermoid tumours, but were absent in adenoid cystic carcinoma and adenocarcinoma. Relative area estimation of hyaline cells in pleomorphic adenomas showed that this may range from 2.2% to 30.4% of the total tumour area. The usefulness of the hyaline cell as a diagnostic criteria in distinguishing between some of the salivary gland tumours was also discussed.