Cementum-like material in a case of Pindborg tumor.

Pindborg tumor is characterized by the production of large amounts of amyloid and the presence of calcified lamellar bodies. These bodies were investigated at both the light and ultrastructural levels in a case of Pindborg tumor showing extensive calcification. It was found that the great majority represented calcified amyloid. However the outer layer or layers in some of these bodies consisted of typically banded calcified collagen which was referred to in this paper as (cementum-like material). This term was preferred over (bone-like material) because of the striking similarity between the arrangement of collagen in this layer and that of cemental Sharpy's fibers. It is therefore suggested that although the majority of the calcified lamellar bodies in this tumor represents calcified amyloid, cementum-like material may also contribute a part.

Immunohistochemical analysis of bone morphogenetic protein (BMP) in osteosarcoma.

The monoclonal antibody against bovine bone morphogenetic protein (bBMP-McAb) was first used for demonstration of bone morphogenetic protein (BMP) in osteosarcoma. The avidin-biotin complex method (ABC) demonstrated that of the 18 osteosarcomas, 15 stained positive, while all 6 fibrosarcomas were negative. The results showed that BMP mainly exists in the tumor cell plasma and some tumor-like bone tissues. Using this staining method, we can not only differentiate osteosarcoma from fibrosarcoma and other non-bone-derived tumors, but also classify osteosarcoma according to the content and distribution of BMP and the patient's clinical situation, thus providing a scientific basis for clinical treatment.

Globular hyaline masses in the stroma of ameloblastoma: histopathologic and histochemical study.

A microscopical study of 15 intraosseous ameloblastomas revealed the presence of globular hyaline masses in only one of them (6.6%). These masses were confined to the stroma of plexiform areas and especially in regions undergoing cystic degeneration. They were periodic acid-Schiff positive and showed an affinity for acid dyes such as phloxine, acid fuchsin, orange G and picric acid. Regarding their pathogenesis, they are probably formed from extravasation of plasma glycoproteins, condensing and taking up a spheroidal shape in the liquid micro-environment of stromal degeneration under the influence of capillary phenomena.

Adenomatoid odontogenic tumour: co-expression of keratin and vimentin.

Immunohistochemical observations of intermediate sized proteins in five cases of adenomatoid odontogenic tumour (AOT) are described. The immunohistochemical detections of keratins were made with polyclonal antiserum (TK, 41-65 kDa) and three monoclonal keratin antibodies (KL1: 55-57 kDa; PKK1: 40, 45, and 52.5 kDa and nos. 19, 18, 8; K8.12: nos. 16, 13) and vimentin and desmin monoclonal antibodies. Histologically, the tumour epithelia could be divided into two types: type A cells were a spindle or columnar shape and formed solid, ductal, tubular or whorled structures. Type B cells were small and compact cells at the periphery of the A cell-containing focus. Immunohistochemically, the type A cells showed very slight reaction with all antibodies to keratins, whereas the type B cells indicated slight-to-moderate expression of keratin and vimentin, and showed coexpression. Both types of cell showed a negative reaction for desmin. Only one case was associated with cystic lesions, and the cyst-lining was composed of thin squamous epithelium. Keratin expression in this epithelium was strong. In the histogenesis of AOT it was postulated that the tumour cells may have originated from undifferentiated odontogenic epithelium or stratum intermedium cells.

Identification of basement membrane components and intermediate filaments in calcifying epithelial odontogenic tumors.

An immunohistochemical technique was used on paraffin-embedded tissues of four cases of calcifying epithelial odontogenic tumors (CEOT). These studies were performed to gain an additional understanding of the nature of amyloid-like deposits in these tumors. For these studies antibodies to Type IV collagen, laminin, and the five classes of intermediate filament proteins were employed. In all of the tumors examined basement membrane components and intermediate filament proteins (cytokeratin) were demonstrated both in the epithelial tumor islands and within the extracellular amyloid-like deposits. Antibodies to vimentin intermediate filaments were localized only in the stromal fibroblasts. Limited proteolysis or the use of a chaotropic agent was required to express the antigenic determinants present. These studies substantiate the presence of basement membrane components in the amyloid-like deposits of CEOT. In addition, these extracellular deposits are shown to be heterogenous in composition by the immunohistochemical demonstration of cytokeratin intermediate filament proteins.

Primary B-cell malignant lymphoma of the maxilla with a sarcomatous pattern and multilobated nuclei.

Three cases of primary malignant lymphoma of the maxilla are reported. The primary intraosseous origin of these tumors was demonstrated by x-ray examination and surgical exploration. The initial interpretation as odontogenic infection led to a delay in starting therapy of 9 months in one case. Biopsies of two cases were initially interpreted as sarcoma because of a dense reactive fibrosis between the tumor cells. Subsequently, hemimaxillectomy was performed in one case. Histologically and ultrastructurally the tumor cells showed marked nuclear abnormalities with cleavage, folding, and lobulation. Immunohistochemical studies of two cases showed a monoclonal immunoglobulin expression, IgG-K; T-lymphocyte-associated antigens were not detected on the tumor cells. The findings indicate the existence of a primary B-cell malignant lymphoma of bone with multilobated nuclei. The lymphoid nature may be masked by a dense proliferation of connective tissue. The relation of these tumors to the classifications for malignant lymphoma of lymph node is discussed.

Gigantiform cementoma: review of the literature and a case report.

Gigantiform cementoma is a very rare lesion in the jaw. A 64-year-old caucasian female who presented with this condition is reported and the relevant literature reviewed. The difficulty of making a definitive diagnosis on histological grounds is discussed. An attempt has been made to analyse the lesion biochemically in order to confirm its cemental origin.

Malignant melanotic neuroectodermal tumor of infancy: a clinical, pathologic, ultrastructural and tissue culture study.

The melanotic neuroectodermal tumor of infancy is an uncommon neoplasm typically of early childhood which has a predilection for the head and neck region, particularly the maxilla. Except for one previous example in the literature, this tumor has consistently behaved in a benign fashion. This study documents the clinical course and pathologic findings of a tumor which began in the maxilla of a 4-month-old boy, followed by a local recurrence, metastasis to a cervical lymph node and finally, widespread dissemination and death at 18 months, 24 months and 38 months, respectively. The tumor was initially composed of nests consisting of melanin-containing cells and small dark cells. An elevated vanillylmandelic acid level was recorded during the course of the disease. At autopsy, the tumor in lymph nodes, liver, bone and soft tissues had a monotonous pattern of small dark cells similar to a conventional neuroblastoma. Previous ultrastructural studies indicate that the melanotic neuroectodermal tumor of infancy is composed of melanocytes and neuroblast-like cells. Our case provided the unique opportunity to examine in sequence the ultrastructural and in vitro characteristics of a recurring and eventually metastasizing melanotic neuroectodermal tumor. Although the neuroblast-like cells were initially difficult to identify by electron microscopy, a melanin-producing cell line and a separate nonpigmented cell line were successfully isolated from various tumor explants. Various stages of melanosome development were identified in the pigmented cells from the local recurrences and in vitro. Dibutyryl cAMP accentuated the formation of pigment and dendritic development in the melanocytes and dendrites only in the small nonpigmented cells. Electron dense granules were observed in the cultured smaller cells and also in the lymph node and soft tissue metastases. Tyrosine hydroxylase activity was demonstrated in the neuroblast-like cells. In the final biopsy and autopsy material, only the neuroblast-like cells remained and the tumor resembled a conventional neuroblastoma.