Stiff person syndrome (SPS) is a rare autoimmune disease caused by lack of inhibition to excitatory neurotransmitters in the central nervous system (CNS) leading to inappropriate motor unit firing. The pathophysiology is incompletely understood; however, high titers of antiglutamic acid decarboxylase antibody (anti-GAD Ab) are strongly associated with this disease. We present a 50-year-old woman with a history of ongoing gait and balance issues for 5 years with multiple negative workups. She recently had an acute exacerbation which left her bedbound, unable to move her legs or turn from side to side. After a negative workup at an outside hospital, the patient was discharged to a subacute rehabilitation facility. She then presented to our institution due to worsening of her condition and was ultimately diagnosed with SPS which was successfully treated. We review the case presentation and treatment options in the context of a severe disabling disease presentation.

Among thoracic tumors, these include subsets of a relatively newly described and yet to be fully characterized tumor entity: SMARCA4-deficient Undifferentiated Tumor (SMARCA4-dUT). Mutations of SMARCA4 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4) gene and loss of BRG1 (Brahma-related gene-1) is the underlying molecular hallmark of SMARCA4-dUT. They mostly involved the mediastinum, lung, and/or pleura showing undifferentiated round cell or rhabdoid morphology associated with aggressive clinical behavior. The pathogenesis of these tumors is still not clear. Morphologically, SMARAC4-dUT is differentiated from SMARCA4-dNSCLC by the presence of squamous and solid components in the latter. Immunohistochemically SMARC4-dUT has characteristic loss of SMARCA4 and SMARCA2 and strong expression of SOX2, CD34, and SALL4. Common sites of metastasis include lymph nodes, bones, and adrenal glands but rarely brain metastasis. We present a unique and rare case of a 76-year-old male with a right lung mass with documented pathology of SMARCA4-dUT and was found to have multiple brain metastases.

e16169 Background: Surgical resection can provide an increase in survival for incurable patients with cholangiocarcinoma (CCA); Since outcomes improve significantly with more aggressive intervention liver resection (LR) should be pursued together with common bile duct resection (CBDR). We aimed to analyze the trends of surgical management of hilar CCA also known as Klatskin tumor (KT) across 15 years in the U.S. Methods: We extracted two cohorts of hospitalizations from Nationwide Inpatient Sample (NIS) 2005-2019yy using ICD-9 and ICD-10 diagnosis and procedure codes for KT, CBDR and LR. First group of patients with KT had CBDR performed alone and the second group of KT patients received CBDR and LR during the same hospitalization. We compared mortality, performed socio-demographic analysis stratified by patient and hospital information and used length of stay (LOS) and mean charges (MC) as additional outcomes. Results: We extracted a total of 3,095 hospitalizations with KT that underwent CBDR alone or CBDR with LR. There was a transition in proportion of CBDR alone versus CBDR with LR across years, which we attribute to the change in coding from ICD-9 to ICD- 10, with the combined coding year 2015 demonstrating equalization of proportion of performed procedures prior to the flip in 2016. Since ICD-10 procedure coding was more specific for CBDR and LR, we as a result of this conclude that ICD-10 coding years 2016 and onward are more accurate and the latest trends demonstrate the increasing performance of only CBDR in KT patients rather than CBDR with LR (75% vs. 25% in 2019). Analysis of socio-demographics is presented in the Table. More than 2/3 of the patients were above age 60. Proportionally CBDR alone was more likely to be covered by public insurance than CBDR with LR (Public: 63.7% vs. 57.1%; Private: 34% vs. 40%). Even though it is a more invasive intervention, CBDR with LR had slightly less mean overall charges (MC=$223,903 for CBDR vs. $212,072 for CBDR with LR (P=0.5574)) and similar hospital resource utilization (LOS= 14 days for CBDR vs.14.7 days for CBDR with LR) compared to CBDR alone. Most of the procedures (>94%) were performed in teaching hospitals. Inpatient mortality was 5.5% for CBDR alone vs. 8.7 % for CBDR with LR. Conclusions: Our analysis demonstrated that for KT proportionally, CBDR performance is more prevalent than CBDR with LR in the latest years 2016-2019. Considering the comparable cost and hospital resource utilization with intent to cure, more aggressive surgical management should be pursued. Inpatient mortality was higher for more aggressive surgical management 5.5% for CBDR alone vs. 8.7% for CBDR with LR. Insurance type may play a role in the procedure choice. [Table: see text]

Nodular amyloidoma in the lungs is a rare entity, also the occurrence of extramedullary plasmacytoma (EMP) in the lungs is rare. To have concomitant EMP and amyloidoma presented as a single lung mass is even rarer. There was only one similar case reported in the abstract form previously. Our case did not respond to many novel chemotherapy agents, suggesting that this combination of amyloidoma and plasmacytoma belonged to a poor prognosis entity, requiring different treatment modalities, such as early bone marrow transplantation or CART (chimeric antigen receptors T) therapy.