Architecturally Low-Grade Pure Cylindrocarcinoma With CYLD1 Mutation

Area of Science:

• Dermatopathology
• Oncology
• Genetics

Background:

• Cylindrocarcinoma is a rare malignant adnexal neoplasm.
• Diagnosis often relies on identifying a precursor benign component (cylindroma).
• The World Health Organization classifies these as malignant neoplasms arising from cylindroma.

Purpose of the Study:

• To present a unique case of pure, architecturally low-grade cylindrocarcinoma.
• To support the diagnosis with detailed morphologic and immunohistochemical features.
• To investigate the genetic basis, specifically CYLD1 mutations.

Main Methods:

• Morphological analysis of the tumor.
• Immunohistochemical staining.
• Genetic analysis for CYLD1 mutation.

Main Results:

• The case presented as a pure cylindrocarcinoma without a discernible benign precursor.
• Distinctive morphologic and immunohistochemical findings supported the diagnosis.
• An inactivating mutation in the CYLD1 gene was identified.

Conclusions:

• Pure cylindrocarcinoma, though rare, can occur without a benign component.
• Morphologic and immunohistochemical features are crucial for diagnosis.
• CYLD1 gene mutations may play a role in the pathogenesis of cylindrocarcinoma.