Diagnostic challenges of giant cervical pilomatrixoma mimicking malignancy: case report and focused literature review

TL;DR

A rare large benign tumor in the neck was mistaken for cancer, highlighting the need for accurate diagnosis and proper treatment.

Contribution

Highlights diagnostic challenges of giant cervical pilomatrixoma and emphasizes the role of histopathology and core needle biopsy.

Findings

Giant pilomatrixoma can mimic malignancy in clinical and radiological assessments.

Complete surgical excision provides excellent outcomes with minimal morbidity.

Histopathology is essential for definitive diagnosis and avoiding overtreatment.

Abstract

Pilomatrixoma is a benign skin adnexal tumor arising from the hair-follicle matrix. While typically small and slowly growing, rare “giant” variants (>5 cm)—especially in the cervical region—may clinically and radiologically mimic malignant masses, posing a significant diagnostic challenge. We report a case of a 29-year-old male presenting with a solitary, firm, subcutaneous mass (~6 cm) in the left anterior cervical region, which enlarged rapidly over 6 months without pain or systemic symptoms. Contrast-enhanced CT revealed a well-defined, heterogeneous subcutaneous lesion without muscular or vascular invasion. Core needle biopsy (CNB) supported a diagnosis of pilomatrixoma. The mass was completely excised under IV sedation and local anesthesia. Histopathology confirmed classic pilomatrixoma features (basaloid cells, shadow cells, foreign-body giant cell reaction). At one-year follow-up the patient was disease-free, and scar outcome was excellent. This case underscores the importance of including giant pilomatrixoma in the differential diagnosis of large cervical soft-tissue masses. Histopathological examination remains essential for definitive diagnosis, while CNB can guide preoperative planning. Complete surgical excision yields excellent outcomes with minimal morbidity, avoiding overtreatment for suspected malignancy.

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