Beyond P-SYN: Why CND Evaluates Skin Histology
Todd Levine, MD
Chief Medical Officer
When CND Life Sciences launched the Syn-One Test®, we anticipated that the pathological information gained from a simple, convenient skin biopsy procedure performed in a medical office would offer valuable insights into the clinical diagnosis of patients with complex neurodegenerative diseases. The critical information gained from the presence or absence of phosphorylated alpha-synuclein, combined with an evaluation of the general health of peripheral nerves, has become a regular part of the evaluation of patients with signs and symptoms of a synucleinopathy. With more than 40,000 Syn-One cases performed in clinical practice since 2020, CND appreciates how useful a tool like the Syn-One Test has become in everyday neurological care.
H&E As a Core Component of Syn-One
But there’s another important aspect of the Syn-One Test: the insights provided by the analysis of the hematoxylin and eosin (H&E) stains that CND routinely performs on all skin biopsy samples as part of the Syn-One Test. The H&E stain allows our pathologists to perform a detailed analysis of skin morphology, identifying the potential of incidental dermatologic conditions that a patient might have, even if subclinical. In patients with synucleinopathies, this is critical, as these individuals have a markedly higher rate of dermatologic abnormalities. Cassard et al published a review in 2024 and stated:
“Understanding the dermatologic aspects of Lewy body disease not only contributes to its holistic characterization but also holds implications for innovative diagnostic approaches.”1
Image. Hematoxylin and eosin staining of 3mm punch biopsy
There are several publications over the last 10 years describing the links between Parkinson’s disease and skin pathologies, noting the higher relative incidence rates of malignant and benign conditions found in patients with Parkinson’s versus the general adult population. Niemann et al noted in Parkinsonism and Related Disorders in 2021:
“As these conditions can have implications on the patient’s quality of life and prognosis, a high index of suspicion for PD in certain skin disorders and vice versa is therefore critically important.” 2
What CND Has Found to Date
In more than 32,000 Syn-One Tests analyzed by CND’s teams of dermatopathologists and other certified anatomical pathologists from January 2023-May 2025, nearly 40% had reportable dermatological findings. While most of these cases noted benign abnormalities, some cases with serious conditions were identified and resulted in immediate referral to a dermatologist. These included suspected basal cell carcinoma, spongiotic dermatitis with eosinophilia, and junctional melanocytic proliferation. Over the years, CND’s growing collection of Syn-One Test pathology reports has provided valuable insights into dermatological findings and trends.
As a company that has pioneered the use of skin biopsies to uncover important pathological insights for patients with a suspected synucleinopathy, CND takes the responsibility of identifying other notable skin abnormalities seriously. We continue to learn more about the connections between these dermatological findings and central nervous system diseases and look forward to adding to the published literature in the future.
Upon receiving the Syn-One Test pathology report, if you have questions about abnormal H&E findings, you can consult with CND’s dermatopathologists to review the results.
Learn more about the Syn-One Test
1Cassard L, Honari G, Tousi B. The skin and Lewy body disease. J Alzheimers Dis. 2024;100(3):761-769. doi:10.3233/JAD-240198
2Niemann N, Billnitzer A, Jankovic J. Parkinson’s disease and skin. Parkinsonism Relat Disord. 2021;82:61-76. doi:10.1016/j.parkreldis.2020.11.017
