TY - JOUR
T1 - Immunotherapy-refractory vacuolar myopathy with mucin deposition in scleromyxedema
T2 - A possible role of fibroblast growth factor 2
AU - Yanagihara, Yuki
AU - Hayashi, Shintaro
AU - Koge, Junpei
AU - Honda, Hiroyuki
AU - Yamasaki, Ryo
AU - Yamada, Yuichi
AU - Oda, Yoshinao
AU - Iwaki, Toru
AU - Kira, Jun ichi
N1 - Publisher Copyright:
© 2020 Japanese Society of Neuropathology
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Scleromyxedema (SME) is characterized by widespread waxy papules on the skin, with mucin deposits in the upper dermis. Twenty-one SME cases of myopathy have been reported; of the cases, six showed vacuolar formation, and two showed mucin deposition. We report the first case of SME with mucin-associated vacuolated fibers. A 45-year-old woman with SME developed progressive proximal muscle weakness. Muscle biopsy revealed myopathic changes with numerous vacuoles linked to mucin in the affected muscle fibers, which were heavily immunostained for fibroblast growth factor 2 (FGF2). Despite repeated high dose oral prednisolone and intravenous immunoglobulin administrations, muscle weakness recurred continuingly, culminating in death due to congestive heart failure. Immunotherapy was partly effective in our case, although it was refractory. Treatment responsiveness in patients with SME myopathy varied; however, due to its rarity, the mechanism remains to be elucidated. To address this issue, we investigated muscle specimens immunohistochemically and detected marked upregulation of FGF2 in the affected muscle fibers of our patient. FGF2, a strong myogenesis inhibitor, may exert a suppressive effect on muscle fiber regeneration, which may have conferred refractoriness to our patient's SME myopathy.
AB - Scleromyxedema (SME) is characterized by widespread waxy papules on the skin, with mucin deposits in the upper dermis. Twenty-one SME cases of myopathy have been reported; of the cases, six showed vacuolar formation, and two showed mucin deposition. We report the first case of SME with mucin-associated vacuolated fibers. A 45-year-old woman with SME developed progressive proximal muscle weakness. Muscle biopsy revealed myopathic changes with numerous vacuoles linked to mucin in the affected muscle fibers, which were heavily immunostained for fibroblast growth factor 2 (FGF2). Despite repeated high dose oral prednisolone and intravenous immunoglobulin administrations, muscle weakness recurred continuingly, culminating in death due to congestive heart failure. Immunotherapy was partly effective in our case, although it was refractory. Treatment responsiveness in patients with SME myopathy varied; however, due to its rarity, the mechanism remains to be elucidated. To address this issue, we investigated muscle specimens immunohistochemically and detected marked upregulation of FGF2 in the affected muscle fibers of our patient. FGF2, a strong myogenesis inhibitor, may exert a suppressive effect on muscle fiber regeneration, which may have conferred refractoriness to our patient's SME myopathy.
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U2 - 10.1111/neup.12659
DO - 10.1111/neup.12659
M3 - Article
C2 - 32424839
AN - SCOPUS:85084850603
SN - 0919-6544
VL - 40
SP - 492
EP - 495
JO - Neuropathology
JF - Neuropathology
IS - 5
ER -