A Case of Kerion Celsi Caused by Trichophyton tonsurans, a Plate Culture of Which Showed Yellow-Green Fluorescence Under UVA Light.

We herein report a case of kerion celsi of the scalp and tinea corporis due to Trichophyton tonsurans. A 17-year-old Japanese male high school student who practiced judo had alopecic patches with severe inflammation on the scalp. We performed a fungal culture and identified the causative fungus as T. tonsurans. A plate culture of T. tonsurans showed lemon-yellow colonies with yellow-green fluorescence under UVA light, which are typical findings for Microsporum canis. However, genetic analysis of the ribosomal RNA gene of the isolate facilitated differential diagnosis of T. tonsurans.In contrast to dermatophytosis due to other dermatophytes, the clinical features of infection caused by T. tonsurans, an anthropophilic dermatophyte, are initially not very apparent and, thus, are frequently overlooked. We herein present a case of a severe type of kerion celsi caused by T. tonsurans with a fluorescence pattern mimicking M. canis colonies under UVA light. We suspect that yellow pigment metabolites, such as riboflavin, which are fluorescent under UV when secreted into the culture medium, are the virulence factors for not only M. canis, but also T. tonsurans, as shown in the present case.

Application of electron microscopic analysis and fluorescent in situ hybridization technique for the successful diagnosis of extraskeletal Ewing's sarcoma.

The diagnosis of soft tissue tumors is often challenging. Immunohistochemical investigation, let alone routine histopathological investigation, may not allow definitive diagnosis in some cases. To overcome such difficulties, more advanced techniques need to be adopted. Herein, we report an extremely rare 56-year-old Japanese female case of extraskeletal Ewing's sarcoma (ES), successfully diagnosed by electron microscopy (EM) using formalin-fixed sections and fluorescence in situ hybridization (FISH). The patient had a 2-year history of a tumor growing on the leg. In routine histopathology, invasive proliferation of tumor cells was observed in the dermis. Tumor cells were round and uniform with large hyperchromatic nuclei, which were positively stained for CD56, VS38c, Ki-67, MIC2 and vimentin, but not for pan-keratin AE1 + AE3, cytokeratin 20, chromogranin A, synaptophysin and neuron-specific enolase. As these findings were not conclusive to make the final diagnosis, EM specimens were prepared from formalin-fixed sections and subjected to investigation. Cell surface projections and dense core granules were detected, suggestive of either Merkel cell carcinoma or extraskeletal ES. Subsequent FISH analysis identified reciprocal translocation of the ESWR1 gene, enabling the final diagnosis of extraskeletal ES. This study provides useful information enabling the diagnosis of this uncommon soft tissue tumor.

Two cases of erythema exsudativum multiforme associated with Chlamydia pneumoniae infection.

We report two cases of erythema exsudativum multiforme (EEM) that we concluded were caused by infections with Chlamydia pneumoniae. High titers of IgG antibody for Chlamydia pneumoniae were shown in the sera of both cases. One case showed the classical symptoms of pneumonia together with radiological changes in the chest; the other case did not show these symptoms. To the best of our knowledge, only three cases of erythema multiforme associated with Chlamydia pneumoniae infection have been reported.