• 대한세포병리학회지
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• 제17권2호
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• pp.143-147
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• 2006

Merkel cell carcinoma (MCC), a rare primary cutaneous small cell neuroendocrine carcinoma, is a tumor with distinct cytological features. In many cases, immunohistochemical staining (IHC) is required for the differentiation from other small round cell malignancies. Here we describe the cytological findings of Merkel cell carcinoma; these findings contributed to the diagnosis prior to performing IHC. A lower eyelid mass was excised and submitted for frozen section diagnosis. The frozen section diagnosis was consistent with a malignancy, but the more specific diagnosis was limited by the lack of specific histological features. Touch imprint cytology revealed a high cellularity with loosely cohesive small to large sized cells. The tumor cells showed hyperchromatic nuclei with fine chromatin and inconspicuous nucleoli, and thin-rimmed-cytoplasm including the characteristic eosinophilic button-like paranuclear inclusion, previously described as a pathognomonic cytological finding of MCC; this was not found in the H&E frozen section. In conclusion, we suggest that the touch imprint cytology may help in the differential diagnosis of small round cell neoplasms prior to performing IHC especially in frozen section diagnosis.

• Journal of Korean Neurosurgical Society
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• 제48권1호
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• pp.73-78
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• 2010

Objective : Streptococcus pyogenes is a beta-hemolytic bacterium that belongs to Lancefield serogroup A, also known as group A streptococci (GAS). There have been five reported case in terms of PubMed-based search but no reported case of brain abscess caused by Streptococcus pyogenes as a result of penetrating skull injury. We present a patient who suffered from penetrating skull injury that resulted in a brain abscess caused by Streptococcus pyogenes. Methods : The patient was a 12-year-old boy who fell down from his bicycle while cycling and ran into a tree. A wooden stick penetrated his skin below the right lower eyelid and advanced to the cranium. He lost consciousness on the fifth day of the incident and his body temperature was measured as $40^{\circ}C$. While being admitted to our hospital, a cranial computed tomography revealed a frontal cystic mass with a perilesional hypodense zone of edema. There was no capsule formation around the lesion after intravenous contrast injection. Paranasal CT showed a bone defect located between the ethmoidal sinus and lamina cribrosa. Results : Bifrontal craniotomy was performed. The abscess located at the left frontal lobe was drained and the bone defect was repaired. Conclusion : Any penetrating lesion showing a connection between the lamina cribrosa and ethmoidal sinus may result in brain abscess caused by Streptococcus pyogenes. These patients should be treated urgently to repair the defect and drain the abscess with appropriate antibiotic therapy started due to the fulminant course of the brain abscess caused by this microorganism.