Alveolar soft part sarcoma of the larynx: A case report of an unusual location with immunohistochemical and ultrastructural analyses. Head Neck. 2008 Feb 19.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare mesenchymal neoplasm of uncertain origin. In this article, we report a case of ASPS occurring in the larynx, an extremely rare location for this rather unusual tumor. METHODS AND RESULTS: The patient was a 34-year-old Japanese woman who requested an examination for hoarseness. The tumor showed a proliferation of large polygonal cells with periodic-acid-Schiff-positive diastase-resistant intracytoplasmic granules, arranged in an alveolar growth pattern. The cytoplasm of the tumor cells was eosinophilic. Tumor cells were positive for vimentin and titin. Nuclear immunoreactivity for TFE3 was observed, and the Ki-67 labeling index was 14.7%. Ultrastructurally, electron-dense rod-shaped crystals were infrequently observed in the cytoplasm. This case was finally diagnosed as ASPS of the larynx. CONCLUSION: We discuss the histogenesis and differential diagnosis of ASPS with immunohistochemical and ultrastructural findings. TFE3 immunohistochemistry was found to be a very useful marker for the diagnosis of ASPS.

Primary alveolar soft-part sarcoma of the liver: anomalous presentation of a rare disease.Am Surg. 2008 Jan;74(1):43-6.

Alveolar soft-part sarcoma is a highly vascular soft-tissue tumor that is uniformly malignant. It comprises less than 1 per cent of all soft-tissue sarcomas. Patients with alveolar soft-part sarcoma most frequently are aged 15 to 35 years, and the soft tissues of the lower extremities typically are affected. In the pediatric population, it most frequently occurs in the head and neck and particularly affects the tongue and orbit. Alveolar soft-part sarcoma has been described as a primary lesion in the trunk, upper extremities, and retroperitoneum; more novel locations include the mediastinum, female genital tract, stomach, bone, and larynx. Numerous case reports describe alveolar soft-part sarcoma in diverse anatomic locations, but this report is, to our knowledge, the first documentation of primary alveolar soft-part sarcoma of the liver. We describe a 47-year-old woman with such a manifestation. Despite surgical resection and numerous chemotherapeutic regimens, this patient had widespread metastasis and died approximately 2 years after the diagnosis was established.