IgM Pleural Amyloidosis Diagnosed by Pleural Effusion Cell Block: A Case Report
Abstract
Immunoglobulin light chain (AL) amyloidosis is characterized by the systemic deposition of light-chain-derived amyloids. Immunoglobulin M (IgM)-associated AL amyloidosis is extremely rare and clinically distinct. A 70-year-old man presented with dyspnea, bilateral pleural effusion, and mediastinal lymphadenopathy on computed tomography (CT). Amyloid was detected in a pleural effusion cell block and confirmed via an axillary lymph node biopsy. Serum studies and bone marrow findings supported IgM-λ AL amyloidosis associated with Waldenström macroglobulinemia/lymphoplasmacytic lymphoma. First-line therapy failed, but second-line therapy reduced pleural effusion, avoiding thoracentesis for one year. A pleural effusion cell block analysis enabled rapid diagnosis with minimally invasive exploration.
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BibTeX
@article{suzuki2026pleural,
title = {{IgM Pleural Amyloidosis Diagnosed by Pleural Effusion Cell Block: A Case Report}},
author = {Ayana Suzuki and Takahiro Suzuki and Kakeru Hisakane and Yukari Shirakura and Kenichiro Atsumi and Yasuko Kuribayashi and Katsutoshi Ozaki and Koji Nagata and Masahiro Seike and Takashi Hirose},
journal = {Internal Medicine},
year = {2026},
month = aug,
doi = {10.2169/internalmedicine.7237-26},
url = {https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_7237-26/_article},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - IgM Pleural Amyloidosis Diagnosed by Pleural Effusion Cell Block: A Case Report
AU - Ayana Suzuki
AU - Takahiro Suzuki
AU - Kakeru Hisakane
AU - Yukari Shirakura
AU - Kenichiro Atsumi
AU - Yasuko Kuribayashi
AU - Katsutoshi Ozaki
AU - Koji Nagata
AU - Masahiro Seike
AU - Takashi Hirose
PY - 2026
DA - 2026/08/08
JO - Internal Medicine
DO - 10.2169/internalmedicine.7237-26
UR - https://www.jstage.jst.go.jp/article/internalmedicine/advpub/0/advpub_7237-26/_article
AB - Immunoglobulin light chain (AL) amyloidosis is characterized by the systemic deposition of light-chain-derived amyloids. Immunoglobulin M (IgM)-associated AL amyloidosis is extremely rare and clinically distinct. A 70-year-old man presented with dyspnea, bilateral pleural effusion, and mediastinal lymphadenopathy on computed tomography (CT). Amyloid was detected in a pleural effusion cell block and confirmed via an axillary lymph node biopsy. Serum studies and bone marrow findings supported IgM-λ AL amyloidosis associated with Waldenström macroglobulinemia/lymphoplasmacytic lymphoma. First-line therapy failed, but second-line therapy reduced pleural effusion, avoiding thoracentesis for one year. A pleural effusion cell block analysis enabled rapid diagnosis with minimally invasive exploration.
SN - 1349-7235
SN - 0918-2918
ER -