Scalp metastases from thyroid carcinomas: review of clinical and pathological features

Abstract:

Thyroid carcinomas reported to metastasize to scalp were reviewed and discussed with histopathological, prognostic and diagnostic aspects. All cases of scalp metastasis from thyroid carcinomas published in PubMed and MedLine were reviewed and the data of all patients were analyzed to obtain information about the patient demographics, histologic type of thyroid carcinoma, additional cutaneous sites, time interval between the diagnosis of the primary tumor and the diagnosis of scalp metastasis. The literature review revealed 38 cases of scalp metastasis from thyroid carcinoma. The most common histologic type was follicular carcinoma (46%), followed by papillary (35%), medullary (16%) and anaplastic carcinomas (3%). Scalp as a distinct cutaneous area has a rich dermal vasculature and is a site of various primary and metastatic neoplasms. Metastases to scalp from thyroid carcinomas are extremely rare and demonstrate advanced disease and poor prognosis. A scalp nodule may be a diagnostic challenge if it is the presenting symptom of an occult neoplasm with low metastatic potential. Awareness of the histopathological characteristics, and cutaneous metastatic patterns of thyroid carcinomas can help us to overcome the difficulty in diagnosis of such lesions.