Fine-needle aspiration of scalp lesions.

Abstract

A variety of inflammatory and neoplastic scalp lesions are encountered in surgical pathology. However, the literature on fine-needle aspirations (FNAs) of the scalp is exceedingly rare. We report on a series of 70 FNAs involving cutaneous and subcutaneous lesions on the scalp. A total of 70 fine-needle aspirations of cutaneous and subcutaneous scalp lesions was reviewed to identify patterns of metastasis to the scalp and to demonstrate the effectiveness of FNA in diagnosing these lesions. There were 42 male and 28 female patients, ranging in age from 29-91 yr (mean, approximately 61 yr). Sixty-one patients had a previous history of malignancy. Of these aspirates, 59 were neoplastic, consistent with the patient's known primary. One case was an abscess, and the remaining case was unsatisfactorvy for cytologic evaluation. Follow-up biopsy revealed granulomatous inflammation. The most common primary tumor to metastasize to the scalp was lung carcinoma, which was seen in 18 cases, followed by hematopoietic malignancies in 14 cases. Melanoma was identified in 6 cases, head and neck tumors in 5 cases, renal malignancies in 4 cases, gastrointestinal tumors in 3 cases, sarcoma in 3 cases, breast and prostate malignancy in 2 cases each, and an olfactory neuroblastoma and meningioma in 1 case each. The remaining 9 aspirates were from patients who did not have a previous history of malignancy. These included 6 benign aspirates consisting of 3 epidermal inclusion cysts, 2 lipomas, and 1 neurofibroma. Two aspirates were malignant and included 1 primary squamous-cell carcinoma and 1 metastatic adenocarcinoma of unknown origin. The remaining case was unsatisfactory for cytologic evaluation. Follow-up biopsy of this lesion showed noncaseating granulomas. Of the aspirates from patients with a previous history of malignancy, 97% were neoplastic. Lung carcinoma and hematopoietic malignancies were the most common neoplasms that metastasized to the scalp. Since the scalp is a common site for metastasis, awareness of this fact is useful to both oncologists and dermatologists. It must be understood that FNA can provide a rapid and accurate diagnosis in the evaluation of scalp masses.