小熊 玲奈

＜文献概要＞症例1:66歳,女性.胸部正中の褐色斑を伴う19×17mm大の円形紅斑.症例2:58歳,女性.胸部正中の16×17mm大の不整形褐色斑.ともに胸部正中表在型基底細胞癌と診断し,ケロイド好発部位であることから外科的治療に伴うケロイド形成の可能性を考慮しイミキモド5%クリームで加療を行った.日光角化症に対する加療スケジュールに準じて週3回隔日,4週間外用後に4週間休薬することを1クールとし,2クール外用して褐色斑が改善した.1例目は6ヵ月後に再発を疑う褐色斑が出現したため再度イミキモドを同スケジュールで外用し,改善した.その後現在まで2例とも再発・ケロイド形成なく経過良好である.再発率を考慮した場合の治療方針の第一選択は手術であるが,ケロイド好発部位の表在型基底細胞癌には,整容面を考慮し,イミキモド外用が有用な治療手段となる可能性がある.

＜文献概要＞79歳,男性,農家.1ヵ月前より生じた鼻尖部紅斑に対してステロイド軟膏を外用し鼻瘤様の外観を呈した.皮膚生検にて真皮内に多数の円形の菌体成分を混じる肉芽腫像を認めた.細菌培養検査ではメチシリン感受性黄色ブドウ球菌(methicillin-sensitive Staphylococcus aureus:MSSA),真菌培養検査ではSporothrix schenckiiが検出された.セファレキシン内服にて痂皮は大部分が消失し,腫脹も改善したが紅斑は残存した.その後,rDNA ITS領域の塩基配列からSporothrix globosaと同定され,内服薬をヨウ化カリウムに切り替えたところ紅斑も消退した.MSSAとSporothrix globosaの混合感染であったと考えた.自験例のような鼻瘤様の外観など,非典型な臨床所見を呈したスポロトリコーシスでは,黄色ブドウ球菌など他の病原微生物の混合感染を念頭に組織培養の結果を検討することが治療方針を決定するにあたり肝要である.

Atopic dermatitis (AD) is commonly associated with colonization by Staphylococcus aureus in the affected skin. To understand the role of S. aureus in the development of AD, we performed whole-genome sequencing of S. aureus strains isolated from the cheek skin of 268 Japanese infants 1 and 6 months after birth. About 45% of infants were colonized with S. aureus at 1 month regardless of AD outcome. In contrast, skin colonization by S. aureus at 6 months of age increased the risk of developing AD. Acquisition of dysfunctional mutations in the S. aureus Agr quorum-sensing (QS) system was primarily observed in strains from 6-month-old infants who did not develop AD. Expression of a functional Agr system in S. aureus was required for epidermal colonization and the induction of AD-like inflammation in mice. Thus, retention of functional S. aureus agr virulence during infancy is associated with pathogen skin colonization and the development of AD.

＜文献概要＞85歳,女性.難治性両下腿浮腫に対し,深部静脈血栓症予防目的にワルファリンカリウムを内服していた.当科受診4日前に増悪した右足背の腫脹・滲出液に対し,前医にて蜂窩織炎の診断となり,セフカペンピボキシル塩酸塩水和物の内服が開始された.当科受診当日,左下腿に腫脹と疼痛を自覚し救急要請した.搬送中に同部の急激な増大と皮膚の破裂をきたし,出血性ショックとなった.当院到着後,救急救命科により初期蘇生された.CT画像所見において出血部位の皮下に巨大血腫が確認された.保存的加療により血腫直上の皮膚は壊死となり,治療として外科的デブリードマンによる血腫除去術と分層植皮術を施行した.自験例を深在性解離血腫(deep dissecting hematoma:DDH)と診断した.DDHは初期には丹毒や蜂窩織炎と認識されることが多く,診断には出血素因,内服歴などの問診や皮膚脆弱性の観察が重要である.治療では血腫除去が遅れると広範な皮膚壊死をきたすため,早期に外科的処置による血腫除去が望まれる.

CONTEXT: Necrolytic migratory erythema (NME) occurs in approximately 70% of patients with glucagonoma syndrome. Excessive stimulation of metabolic pathways by hyperglucagonemia, which leads to hypoaminoacidemia, contributes to NME pathogenesis. However, the molecular pathogenesis of glucagonoma and relationships between metabolic abnormalities and clinical symptoms remain unclear. PATIENT: A 53-year-old woman was referred to our hospital with a generalized rash and weight loss. NME was diagnosed by histopathological examination of skin biopsy tissue. Laboratory tests revealed diabetes, hyperglucagonemia, marked insulin resistance, severe hypoaminoacidemia, ketosis, and anemia. Enhanced computed tomography scans detected a 29-mm pancreatic hypervascular tumor, which was eventually diagnosed as glucagonoma. Preoperative treatment with octreotide long-acting release reduced the glucagon level, improved the amino acid profile, and produced NME remission. Surgical tumor excision normalized the metabolic status and led to remission of symptoms, including NME. INTERVENTIONS: Whole-exome sequencing (WES) and subsequent targeted capture sequencing, followed by Sanger sequencing and pyrosequencing, identified biallelic alteration of death-domain associated protein (DAXX) with a combination of loss of heterozygosity and frameshift mutations (c.553_554del:p.R185fs and c.1884dupC:p.C629fs) in the glucagonoma. Consistently, immunohistochemistry confirmed near-absence of DAXX staining in the tumor cells. Tumor expression of glucagon and somatostatin receptor subtype 2 and 3 messenger RNA was markedly upregulated. CONCLUSIONS: This is a report of glucagonoma with biallelic inactivation of DAXX determined by WES. The tumor manifested as glucagonoma syndrome with generalized NME. This case showed the relationship between hypoaminoacidemia and NME status. Further investigations are required to elucidate the underlying mechanisms of NME onset and glucagonoma tumorigenesis.