1/10. Odontogenic myxoma containing osteocement-like spheroid bodies: report of a case with an unusual histopathological feature.The odontogenic myxoma is a rare, benign, but locally invasive tumour of the jaws. Radiographically, it is a bone destroying lesion and has ill-defined borders. Histological characteristics are spindle and stellate-shaped tumour cells and a distinct myxomatous stroma. Bony islands that represent residual trabeculae are found scattered throughout the lesion. This report describes a case of odontogenic myxoma that shows diffusely dispersed osteocement-like spherular calcified bodies, unlike residual bone trabeculae, and discusses its differential diagnosis.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
2/10. Calcified vestibular schwannoma with unusual histological characteristics - positive immunoreactivity for CD-34 antigen.Calcification in vestibular schwannoma is extremely rare. A 36-year-old man presented with a history of decreased hearing on the left since childhood. Computed tomography showed a left cerebellopontine angle lesion protruding into the porus acousticus and enlarging the internal auditory meatus, with significant deposits of calcification. Histological and immunohistochemical examination, including staining for CD-34, a myeloid progenitor cell antigen, found highly degenerated schwannoma with collagen-rich tissue, calcification, formation of bone, abnormal vessels of various sizes, and old haemorrhage with marked haemosiderin-laden macrophages. Most of the surgical specimen was sclerotic collagenous tissue containing sparse spindle-shaped cells which formed approximately 90% of the total specimen. However, the spindle-shaped cells were partly concentrated into islands forming the cellular part (approximately 10% of the total). The spindle-shaped cells in both parts showed almost typical immunohistochemical characteristics of schwannoma. However, many spindle-shaped cells in only the sclerotic part were positive for CD-34, which is widely used for the diagnosis of solitary fibrous tumours. cerebellopontine angle tumour showing fibromatous tissue, including calcification, may contain foci of typical schwannoma. Careful histological examination with detailed immunohistochemical staining is required for the correct diagnosis. In particular, spindle-shaped cells occasionally show positive immunoreactivity for CD-34 antigen in the areas of degenerated and calcified schwannoma characteristic of our case.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
3/10. A variant of calcifying epithelial odontogenic tumor with langerhans cells.A variant of calcifying epithelial odontogenic tumor (CEOT) with langerhans cells is reported. Compared to a typical CEOT, the tumor islands of this case were thin and composed of a small number of polyhedral epithelial cells. Almost no calcification of homogeneous eosinophilic materials was observed. In addition, clear cells which structurally corresponded to Langerhans cell were intermingled in the epithelial islands. These cells stain positively for S-100 protein, lysozome, MT 1, LN-3 and OKT 6 antibodies, but not for keratin antibody. Electronmicroscopic examination revealed the rod-shaped and racket-shaped structures called Birbeck's granules in the cytoplasm of these clear cells. Our observations indicate a variant case of CEOT with langerhans cells in tumor nests.- - - - - - - - - - ranking = 2keywords = island (Clic here for more details about this article) |
4/10. Central odontogenic fibroma.An example of a central odontogenic fibroma is presented. This is a rare, benign neoplasm which affected the molar region of the left side of the mandible of a 63-year-old female Caucasian. Histologically, it consisted of fibroblast-like cells lying in a rather myxomatous delicate collagenous stroma. Few islands of odontogenic epithelium were also found. At the ultrastructural level, the tumour cells contained large numbers of fine filaments with focal densities similar to those described in smooth muscle cells. They also showed a moderately developed r ER. These features are consistent with cells referred to as myofibroblasts.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
5/10. Juvenile aponeurotic fibroma: an ultrastructural study.The light and electron microscopic findings in a case of juvenile aponeurotic fibroma are described. The tumor was composed of fibromatosislike areas and cartilagelike islands with characteristic calcification. The ultrastructural study verified the cartilaginous nature of this tumor. The cartilagelike islands were made up of chondrocytic cells embedded in an abundant intercellular matrix containing fine fibrils, spherical granules, and pleomorphic membrane-bound vesicles. The chondrocytic cells had many microvilli, a well-developed granular endoplasmic reticulum, and a prominent Golgi complex. In the periphery of each cartilagelike island was a perichondriumlike structure exhibiting transitional features from fibroblastic cells to chondrocytic cells. The fibromatosislike areas consisted of spindle-shaped fibroblastic cells and occasional myofibroblasts. The morphologic pattern of the tumor somewhat mimics embryonal chondrogenesis, and the fibromatosislike areas may represent an overgrowth of the fibrous layer of the perichondrium. It is possible to regard this tumor as an organoid tumor having a capacity for bidirectional differentiation into cartilage and fibrous tissue.- - - - - - - - - - ranking = 3keywords = island (Clic here for more details about this article) |
6/10. Calcifying amyloidoma of the breast.In this case, a distinctive amyloid tumor of the breast clinically simulated carcinoma, although the patient related onset to trauma. Hepatosplenomegaly, elevated globulins, and anemia led to identification of large amounts of monoclonal IgG-kappa production. The patient died of renal failure within several months despite chemotherapy. The matrix of the breast tumor was tinctorially characteristic of amyloid light chain (AL) protein. The mass contained islands of plasma cells that morphologically suggested local production of amyloid matrix. Moreover, plasma cell and matrix immunohistochemically displayed reactivity of IgG-kappa protein, indicating a clonal plasma cell infiltrate. Pseudo-acinar arrangement of plasma cells may be misinterpreted as epithelial cells in needle biopsy specimens. The notion that some amyloidomas may represent in situ production of protein by clonal immunocytes ("secretory immunocytomas") should be further studied.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
7/10. Non-calcifying Pindborg tumor with langerhans cells.A rare case of calcifying epithelial odontogenic tumor (CEOT) devoid of calcification is reported with histochemical, immunohistochemical and electron microscopic studies. The tumor occurred intraosseously in the left maxillary canine and premolar region of a 58-year-old man. The tumor chiefly consisted of scattered small islands of epithelial cells in an abundant fibro-myxoid connective tissue stroma. Among the nests, there were many spherical bodies of eosinophilic substance for which non-AA amyloid and non-keratin or basal lamina-like natures were demonstrated histochemically and immunohistochemically. In some nests, there were a few, occasionally several, cells positive for S-100 protein. Ultrastructurally, langerhans cells with indented nuclei and Birbeck's granules were seen among tumor cells. The prognostic significance of the paucity of calcification and the presence of langerhans cells in CEOT of which this is only the second description is discussed.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
8/10. Familial gingival fibromatosis with unusual histologic findings.This article describes the occurrence of numerous calcifications, amyloid deposits, and islands of odontogenic epithelium in the gingiva of 3 siblings with familial gingival fibromatosis. These microscopic features have not been reported previously in patients with this condition.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
9/10. Extra-acral calcifying aponeurotic fibroma: a distinctive case with 23-year follow-up.Calcifying aponeurotic fibroma (CAF) is an unusual but well-characterized soft tissue neoplasm that typically involves the digits of children and frequently recurs locally. This report describes a case from the subcutis of the lumbosacral region. A 26-year-old man initially presented at age 3 and developed three recurrences over a 23-year period each at approximately 8-year intervals (ages 10, 18, and 26). The microscopic findings in all recurrences showed a lobulated, poorly circumscribed proliferation of dense fibrous tissue containing epithelioid-like fibroblasts, multinucleated cells, and islands of metaplastic chondroid differentiation with focal calcification. Despite origin from an unusual anatomic site, this case reported herein demonstrates the classical morphologic features and clinical history of CAF which showed little in the way of morphologic evolution despite 23 years of persistence. The clinical and histologic features helpful in distinguishing CAF from infantile fibromatosis and soft tissue chondroma are discussed.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
10/10. Regional odontodysplasia. Report of two cases.Two cases of regional odontodysplasia in girls are reported; one affected the lower incisors, and the other the left maxilla. The first case was radiographically followed over a 6-year period, during which time the ghost teeth exhibited significant dentin formation, along with a resultant decrease in pulp size and relative normalization of the radicular anatomy. The second case involved the deciduous molars and the first permanent molar. In addition to tooth alterations, both cases exhibited many odontogenic epithelial islands and extensive areas of calcification in the mucosa. diagnosis, causes, and treatment are discussed in the light of recent data.- - - - - - - - - - ranking = 1keywords = island (Clic here for more details about this article) |
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