Kenji Kurihara

Solitary fibrous tumor of the oral cavity: report of a case.

A case of benign solitary fibrous tumor of the oral cavity is reported. The tumor occurred in the buccal mucosa of a 34-year-old woman. The surgically removed tumor was 1.5 x 1.2 x 1.0 cm in size and well circumscribed. Histologically, the tumor was composed of spindle-shaped cells that were predominantly arranged haphazardly. Hemangiopericytoma-like areas and collagenous areas were also noted. Immunohistochemically, the tumor cells were positive for CD34 and vimentin. To our knowledge, this is only the second report of solitary fibrous tumor involving the oral cavity.

Tophaceous pseudogout of the temporomandibular joint: Report of a case

An 85‐year‐oid man was found to have a calcified mass protrudlng from the Joint space of the right temporomandibular Joint (TMJ). Microscopically, the removed mass consisted of chondromyxold tissue with atypical chondrocytes, resembling a cartilaginous tumor. However, the chondromyxoid tissue contained abundant deposits of rod‐shaped to rhomboid crystals which proved to be calcium pyrophosphate dihydrate (CPPD) crystals. The review of the literature revealed that tophaceous pseudogout was the most common variant of CPPD deposltion dlsease Involving the TMJ.

Desmoplastic malignant melanoma of the gingiva

A case of desmoplastic melanoma in a 58-year-old man is reported. This rare malignancy occurred in the maxillary alveolus, appearing as an epulis. Histologically, the tumor was flanked by melanocytic proliferation in the adjacent mucosae. At the time of local recurrence after partial maxillectomy, the tumor showed a polypoid growth, with an increase in cellularity and mitotic rate resembling spindle cell carcinoma. The value of immunostaining for diagnosis is stressed.

Carcinoma of the gall‐bladder arising in adenomyomatosis

We describe a case of well differentiated adenocarcinoma of the gall‐bladder that arose from a localized type of adenomyomatosis. Grossly, the cancer was located in the fundus and exhibited a polypoid and well demarcated nodule with multiple small cysts. Histologically, the nodule consisted of glandular structures and stroma containing bundles of smooth muscle cells. The glandular epithelia were varied in appearance, ranging from malignant to benign glands. The adenocarcinoma was limited to the nodule, with normal surface mucosal epithelia and without obvious stromal invasion.

Pigmented variant of benign oncocytic lesion of the pharynx.

A case of pigmented variant of benign oncocytic lesions is reported. The lesion was incidentally found in the pharynx of a 69‐year‐old man, and the gross appearances were multiple, small, flat elevations with black discoloration. Microscopically, ducts of seromucinous glands were replaced by melanin‐containing oncocytes and adjacent dendritic melan‐ocytes. To date, such a pigmented variant of benign oncocytic lesion has not been reported before.

Papillary adenocarcinoma of the epididymis

An 82 year old man with a unilateral epididymal mass was found, on histopathologic examination of a surgically removed specimen, to have a primary papillary adenocarcinoma of a clear cell variant which mimicked renal cell carcinoma. Repeated imaging studies confirmed the absence of renal cell carcinoma. Because the present case had great similarities in histologic appearance and anatomical location to papillary cystadenoma of the epididymis, it may be a malignant Counterpart of the latter type of tumor.

PRIMARY GASTRIC T-CELL LYMPHOMA WITH MANIFOLD HISTOLOGIC APPEARANCES

A rare case of malignant T‐cell lymphoma with manifold histologic appearances was described. The lymphoma occurred in the stomach of a 50‐year‐old Japanese male. Grossly, the lymphoma exhibited a deeply ulcerated mass. Histologically, in addition to diffuse infiltrate of large lymphoid cells with deeply indented nuclei, there were many epithelioid cell granulomas, remarkable tissue eosinophilia and stromal fibrosis, mimicking inflammatory disease. Immunohistochemical studies and a gene analysis demonstrated the T‐cell phenotype.

Epithelioid hemangioma of the maxillary sinus: A case report

x 1.0 cm specimen was obtained. At biopsy, the mass, which was elastic hard in consistency and prone to bleeding, was located in the posterolateral wall and was covered by eroded mucosa. Microscopic examination of the biopsy specimen revealed that the mass was composed of vascular and inflammatory cell components. The vascular component consisted of capillary-sized vessels and medium-sized vessels (Fig 2). Most of the latter vessels were abnormal in that they showed no internal elastic lamina, but had a well-developed muscle layer. The endothelial cells lining the vessels had a plump, eosinophilic cytoplasm, which often contained vacuoles (Fig

ADRENAL MEDULLARY HYPERPLASIA : HYPERPLASIA-PHEOCHROMOCYTOMA SEQUENCE

We present a case of unilateral adrenal medullary hyperplasia in a 63‐year‐old woman with‐clinical signs and symptoms of pheochromocytoma unassociated with multiple endocrine neoplasia. The surgically removed adrenal gland revealed diffuse medullary hyperplasia with multiple micronodules measuring up to 2 mm. The micronodules were composed of enlarged chromaffin cells with atypia, histologically similar to those of pheochromocytoma, forming small solid alveolar patterns separated by a fibrovascular stroma. Removal of the hyperplastic adrenal gland resulted in disappearance of paroxysmal nocturnal hypertension and palpitation. These results suggest that diffuse and nodular medullary hyperplasia is the precursor of pheochromocytoma.

Malignant lymphoma of the esophagus associated with macroglobulinemia: Report of a case

A case of non‐Hodgkins lymphoma of the esophagus in a 74 year old man is presented. Grossly, the surgically removed esophagus had a fuslform submucosal mass covered with smooth surfaced mucosa. Microscopic examination revealed that the mass consisted of a dense infiltrate of small to medium‐sized lymphoid cells with plasmacytoid differentiation, leading to a diagnosis of diffuse small cell lymphoma with lymphoplasmacytic subtype. Laboratory data as well as immunohistochemical studies proved that the lymphoma produced monoclonal immunoglobulin M, giving rise to macroglobulinemia.