Objective:

To report a rare case of folliculosebaceous cystic hamartoma (FSCH) in the vulvar and groin regions, highlighting its clinical presentation and diagnostic challenges.

Approach:

• Case Presentation: A 49-year-old woman with a 20-year history of multiple skin-colored papules and nodules in the right vulva and groin underwent excisional biopsies for diagnosis.
• Histopathological Examination: Initial biopsy showed sebaceous hyperplasia-like changes; subsequent excisions revealed characteristic FSCH architecture.

Key Findings:

• FSCH presented as multifocal, linear/beaded lesions in the vulvar and groin regions.
• Initial biopsy findings were misleading, showing only sebaceous hyperplasia-like features.
• Final diagnosis confirmed FSCH through comprehensive histopathological examination.

Interpretation:

Adequate excisional sampling and clinicopathological correlation are essential for accurate diagnosis of FSCH.

Limitations:

• Initial biopsy did not capture the full diagnostic features of FSCH due to limited sampling.
• No immunohistochemical studies could be performed due to lack of residual tissue.

Conclusion:

This case highlights the rarity of FSCH in genital regions and the potential for misdiagnosis based on limited biopsy samples.