ABSTRACT
Mixed germ cell tumors are rare neoplasms that are known to occur in the anterior mediastinum. Characterized by two or more types of germ cell components, these tumors comprise upwards of 25% of mediastinal germ cell tumors. Even rarer are those harboring somatic-type malignancies such as carcinoma, sarcoma, and hematopoietic malignancies. To date, however, there are no known cases of melanoma arising in a malignant mixed germ cell tumor of the anterior mediastinum. We describe the first case of malignant melanoma with spindle and epithelioid components arising from respiratory epithelium in a mediastinal malignant mixed germ cell tumor of a 32-year-old male. In addition, we also provide evidence supporting the theory of neuroendocrine cells as the origin of melanoma arising in the respiratory epithelium. This case emphasizes the need to carefully evaluate all germ cell tumors, not only for a myriad of benign embryological components, but also for malignancies arising in these components, as they might change the prognosis and patient's course of treatment. This microscopic approach should bring to light the diversity of mixed germ cell tumors in addition to somatic malignancies with corresponding biologic potentials.
Subject(s)
Mediastinal Neoplasms/pathology , Melanoma/pathology , Neoplasms, Complex and Mixed/pathology , Respiratory Mucosa/pathology , Teratoma/pathology , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor/analysis , Biopsy , Chemotherapy, Adjuvant , Humans , Immunohistochemistry , Male , Mediastinal Neoplasms/chemistry , Mediastinal Neoplasms/therapy , Melanoma/chemistry , Melanoma/therapy , Neoadjuvant Therapy , Neoplasms, Complex and Mixed/chemistry , Neoplasms, Complex and Mixed/therapy , Respiratory Mucosa/chemistry , Teratoma/chemistry , Teratoma/therapy , Tomography, X-Ray ComputedABSTRACT
Granular cell tumor is a uncommon disease, although head and neck region accounts for approximately 50% of all lesions, 70% are located in oral cavity but can occur at other site of the body. Clinically, it usually presents as a small, slow growing, non-tender, single benign lesion but mutifocal and malignant forms are rarely encountered. The histogenic origin of this tumor was controversial for many years but recent studies using immunohistochemical study support its origin being from neural cell, probably Schwann's cell. In this report, we present a case of benign granular cell tumor occurred on the hard palate studied by histologic and immunohistochemical assay, with review of literatures.
