Abstract Details

Title Seminoma Resulting in Rapidly Progressive Cerebellar Syndrome with Associated Dual Positive Kelch-like Protein 11 (KLHL11) and Leucine Zipper 4 (LUZP4)–immunoglobulin G (IgG) Antibodies

Topic Autoimmune Neurology

Presentation(s) P2 - Poster Session 2 (2:45 PM-3:45 PM)

Poster/Presentation
Number 077

Objective

To describe a case of a rapidly progressive cerebellar syndrome in a male patient with metastatic retroperitoneal seminoma associated with KLHL11 and LUZP4 antibodies.

Background

Testicular cancers can be associated with paraneoplastic neurologic disorders (PNDs). While testicular cancer-associated PNDs have long been associated with Ma2 antibodies, recently kelch-like protein 11 (KLHL11) and leucine zipper 4 (LUZP4) antibodies were identified.

Design/Methods

Results

A 66-year-old healthy Caucasian male fell and struck his head. He developed increasing difficulties with hearing, balance, incoordination, and weakness. On examination, he had non-sustained nystagmus, L>R dysmetria with overshoot, dysdiadochokinesia, reduced vibration in the left lower extremity, bilateral distal hyporeflexia, positive Romberg, and spastic wide-based gait. His brain MRI showed bilateral cerebellar T2/FLAIR hyperintensity. Spinal MRIs, a testicular ultrasound, and CT scans of the chest, abdomen, and pelvis were unremarkable. A body PET scan revealed a solitary bright 1.2-centimeter aortocaval lymph node. Electromyography revealed a sensorimotor peripheral polyneuropathy of the bilateral lower and left upper extremities. CSF analysis showed 7 white blood cells (normal <= 5), protein 46 (normal 15-45), 10 CSF unique oligoclonal bands, an elevated IgG index of 2.13, and unremarkable cytology. His serum was positive for KLHL11 antibodies at 1:7680. KLHL11 was positive in both serum and CSF. Serum LUZP4 antibodies were strongly positive. Histopathologic staining of the resected lymph node confirmed microclusters of seminoma tumor cells. A 6-month course of IV cyclophosphamide (750 mg/m²) was started. Progression of his PND has halted.

Conclusions

An immune-mediated PND may develop with germ cell seminomas. Two newer high-risk neural autoantibody biomarkers of testicular cancer-associated PND have been recently identified, KLHL11 and LUZP4. These antibodies were crucial to drive the search for a testicular cancer in a male patient with a subacute onset of a rapidly progressive cerebellar syndrome.

Authors/Disclosures
Jenny Linnoila, MD, PhD (University Neurology Associates, UPMC) PRESENTER	Dr. Linnoila has received personal compensation in the range of $10,000-$49,999 for serving as a expert respondent on autoimmune encephalitis with U.S. government/DHHS/Vaccine Injury Compensation Program.
Ryan L. Orie, PA-C (University of Pittsburgh Medical Center)	Mr. Orie has nothing to disclose.
Leonard Appleman	Leonard Appleman has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. The institution of Leonard Appleman has received research support from Astellas. The institution of Leonard Appleman has received research support from BMS. The institution of Leonard Appleman has received research support from Merck. The institution of Leonard Appleman has received research support from Exelixis. The institution of Leonard Appleman has received research support from Arvina. The institution of Leonard Appleman has received research support from Amgen. The institution of Leonard Appleman has received research support from BMS.
Jodie Maranchie	Jodie Maranchie has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. The institution of Jodie Maranchie has received research support from NIH. The institution of Jodie Maranchie has received research support from Janssen. The institution of Jodie Maranchie has received research support from Merck. Jodie Maranchie has received personal compensation in the range of $500-$4,999 for serving as a Grant reviewer with CDMRP. Jodie Maranchie has received personal compensation in the range of $0-$499 for serving as a Grant Reviewer with International Kidney Cancer Association.
Valerie R. Suski, DO (UPMC)	Dr. Suski has nothing to disclose.
Jan Drappatz, MD (University of Pittsburgh Cancer Institute)	Dr. Drappatz has stock in Pfizer. Dr. Drappatz has stock in Vertex. Dr. Drappatz has stock in GSK. The institution of Dr. Drappatz has received research support from Servier. Dr. Drappatz has received publishing royalties from a publication relating to health care.

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