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E Yoneda

Publications and source records attributed to E Yoneda.

7 recordsLinked to original sources
PubMed2001

Malignant gastrointestinal stromal tumor showing remarkable whorl formations.

A case of malignant gastrointestinal stromal tumor (GIST) is reported. Histologically, spindle cell proliferation with remarkable whorl formations was predominant in the tumor. Immunohistochemically, the tumor cells were diffusely positive for CD117 (c-Kit) and vimentin and partially positive for CD34. Ultrastructurally, the desmosome-like structures and interdigitations occurred much more frequently in the areas with whorl formations. These organelles were considered to be closely associated with the whorl formations. Various kinds of cellular arrangements are revealed in GISTs, but remarkable whorl formations, such as in our case, are a rare variant pattern. Herein, we discuss the histopathologic differences between this and other tumors showing whorl formations and describe the meaning of this unique arrangement. GISTs are thought to be immature tumors, and, therefore, variations in histopathologic findings are recognized. Finally, the ultrastructural study of GISTs is useful for understanding the mechanisms forming whorl formations and the differentiation or pathogenesis of GISTs.

Aged↗
PubMed2001

Case report. Cryptococcal cellulitis showing necrotizing vasculitis.

A 65-year-old woman with refractory anaemia who had been treated with systemic corticosteroids for several months developed cryptococcal cellulitis of the right cubital fossa. She was treated empirically for a presumed bacterial cellulitis with little response. Histological examination of debrided tissue revealed Cryptococcus as the causative organism. The tissue reaction involved suppurative inflammation with abscess formation in the dermis and subcutaneous adipose tissue. Necrotizing vasculitis, which has rarely been described in cryptococcosis, was seen in this case. Although the cellulitis was cured by local treatment in this patient, most previous reports recommended systemic antifungal therapy to treat cryptococcal cellulitis.

Aged↗
PubMed2000

Ruthenium-catalyzed cyclic carbonylation of allenyl alcohols. Selective synthesis of gamma- and delta-lactones

[reaction: see text] Ruthenium complex-catalyzed carbonylation of allenyl alcohols quantitatively gave cyclic carbonyl compounds, gamma- and delta-lactones, in which the hydroxy group of allenyl alcohols participated in the cyclization. A wide variety of allenyl alcohols, such as mono-, di-, and trisubstituted alcohols, can be used in this reaction to produce 3- and 4-substituted gamma-lactones. Similarly, the cyclic carbonylation of 3,4-pentadien-1-ol 10a and 2-methyl-4,5-hexadien-2-ol 11a gave delta-lactones, 5,6-dihydro-3-methyl-2H-pyran-2-one 10b, and 5,6-dihydro-6,6-dimethyl-3-methyl-2H-pyran. 2-one 11b, respectively, in a quantitative yield.

Journal Article↗
PubMed2000

[A Warthin's tumor showing extensive necrosis].

Warthin's tumors are one of the most easily recognizable tumors using light microscopy. However, histopathological diagnosis is difficult in a few cases when characteristic cystic cavities with papillary walling and underlying lymphoid stroma are obscured by reactive changes. We describe a case of an extirpated Warthin's tumor of the right parotid gland which demonstrated extensive necrosis, squamous metaplasia and xanthomatous inflammation. No characteristic structure for this tumor was noticed in a section of an initially sampled specimen. As a result, a destroyed fistula was suspected. An additional sampling was performed to confirm the diagnosis and the sampled specimen fortunately demonstrated the diagnostic structure of a Warthin's tumor excluding malignancy. An awareness of the morphological variation seen in this tumor should lead to additional sampling of specimens, thereby preventing erroneous interpretation.

Adenolymphoma↗
PubMed1999

[Subcutaneous phaeohyphomycosis of the right thumb].

Black fungi are a group of fungi that are characterized by the development of a pale brown to black color in the cell walls of their vegetative cells, conidia, or both. A mycotic infection caused by a member of black fungi can be subdivided into three clinical entities: phaeohyphomycosis, chromoblastomycosis, and mycetoma. Phaeohyphomycosis is distinguished from mycetoma by the absence of grain (organized, interwoven mycelial aggregates) formation, and from chromoblastomycosis by the absence of sclerotic bodies (thick-walled muriform cells). Phaeohyphomycosis is a rare disease and has been sporadically reported. In the present report, phaeohyphomycosis of the right thumb of a 72-year-old man was presented. A precipitating trauma of two months earlier at the site was recalled. A solitary mass, 10 mm in diameter, was gradually formed in the palm side of the distal right thumb and finally resected. Histological examination disclosed a solitary granulomatous lesion surrounded by an incomplete fibrous capsule. The lesion mainly involved subcutaneous tissue and was composed of multiple pyogranulomas. Pigmented branched septate hyphae and yeast-like cells were sparsely found in the periphery of the abscess and within histiocytic cells of the granulomas. No sclerotic cells were detected. When pigmentation of black fungi in tissue is as faint as in the present case, Fontana-Masson staining is useful to accentuate the presence of melanin-like pigment of fungal cell walls.

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