Glutamic acid decarboxylase (GAD) antibody-positive paraneoplastic stiff person syndrome associated with mediastinal liposarcoma

Abstract

Stiff person syndrome (SPS) is a rare, debilitating neurological illness characterised by rigidity and spasms of the axial muscles, causing severe restrictions to mobility. SPS can be classic, partial or paraneoplastic. We report a case of a young woman who presented with seizures and painful spasms of the thoracolumbar muscles who was subsequently diagnosed with SPS. Serological work revealed glutamic acid decarboxylase (GAD) antibodies and imaging showed a large mediastinal mass. The patient underwent surgical resection of the mediastinal mass and final pathology revealed well-differentiated mediastinal liposarcoma. She received five sessions of plasma exchange and her neurological symptoms gradually improved after surgery. This case highlights a rare case of GAD antibody-positive paraneoplastic SPS associated with mediastinal liposarcoma.

An update on malignant tumor-related stiff person syndrome spectrum disorders: clinical mechanism, treatment, and outcomes

“…SPSSD is also associated with other carcinomas, such as mediastinal liposarcoma ( 22 ), metastatic adenocarcinoma ( 23 ), pancreatic adenocarcinoma ( 24 ), renal cell carcinoma ( 25 ), mediastinal cancer, undifferentiated carcinoma of an undetermined origin ( 26 ), multiple myeloma ( 86 ), embryonal carcinoma ( 27 ), malignant glioma ( 87 ), ovarian adenocarcinoma ( 88 ), prostate carcinoma ( 88 ), testicular seminoma and germ cell neoplasia ( 88 ), pancreatic cancer ( 88 ), melanoma ( 88 ), an invasive carcinoma of no special type ( 28 ), ovarian teratoma ( 9 ), small cell carcinoma of the bladder ( 31 ), pleuropulmonary blastoma ( 33 ), malignant mesothelioma ( 35 ), colon cancer, and Hürthle cell adenoma ( 36 ). It is also associated with overlapping cancers, such as breast cancer with colon cancer ( 30 , 39 ), chronic lymphocytic leukemia ( 81 ), thymoma and non-Hodgkin lymphoma ( 80 ), non-functioning pituitary microadenoma, and endometrial cancer ( 29 ) ( Table 4 ).…”

“…In addition, SPSSD is associated with breast cancer, small-cell lung cancer, and lymphoma (4, 21). Recently, SPSSD has also been reported to be associated with some rare cancers (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). In this review, we summarize the current literature on malignant tumor-related SPSSDs.…”