# Unveiling the Unusual: A Unique Case of Verrucous Cyst

## TL;DR

A 48-year-old woman with a subcutaneous nodule was diagnosed with a ruptured verrucous cyst, highlighting the need for histopathology and HPV testing to distinguish it from other skin lesions.

## Contribution

This case report provides a detailed clinical and histopathological analysis of a ruptured verrucous cyst with insights into its management and HPV association.

## Key findings

- Verrucous cysts require histopathological and HPV PCR testing for accurate diagnosis.
- The case showed acanthotic papillomatous squamous epithelium with koilocytic changes but no cytologic atypia.
- Verrucous cysts may be associated with high-risk HPV types, raising concerns about malignant transformation.

## Abstract

Verrucous cysts are uncommon types that cannot be distinguished from epidermal inclusion cysts clinically and require histopathological analysis and human papillomavirus (HPV) polymerase chain reaction (PCR) for accurate diagnosis. The pathogenesis of verrucous cysts is thought to involve HPV infection, either of an existing cyst or through direct infection of keratinocytes, leading to new cyst formation. While verrucous cysts can affect individuals of any sex and are typically found on the trunk, extremities, and face, they are particularly notable for their potential association with high-risk HPV types, such as 16 and 18, which may lead to malignant transformation.

In this report, we present the case of a 48-year-old female with a history of endometriosis and pelvic inflammatory disease, who sought evaluation for a persistent subcutaneous nodule on her right flank. The patient reported pain, a recent color change, and an increase in the nodule size. Clinical examination revealed a 2.7 cm subcutaneous nodule with a central brown-gray papule. Despite no history of dermatologic malignancies, the nodule was excised, and subsequent histopathological examination confirmed a diagnosis of a ruptured verrucous cyst. The cyst exhibited acanthotic papillomatous squamous epithelium without cytologic atypia and koilocytic change in cells.

This case offers direct and valuable insights into the clinical presentation, diagnosis, and management of verrucous cysts. It highlights the importance of a thorough diagnostic approach, combining histopathological examination with HPV PCR testing, to accurately differentiate verrucous cysts from other similar cutaneous lesions. The report also emphasizes the need for vigilance in managing these cysts due to their potential association with high-risk HPV types and the consequent risk of malignant transformation. These insights contribute significantly to the existing body of literature on verrucous cysts and aim to enhance clinical awareness and patient care in dermatology.