Alveolar Soft Part Sarcoma of the Head and Neck Region

Abstract

Alveolar soft part sarcoma is a soft tissue malignancy most often found in the extremities of young adults; when these tumors arise in the head and neck area, they usually appear in the orbit or the tongue. Their initial behavior is relatively indolent, but over time a sizable number of these tumors recur locally and metastasize; as such, they are best regarded as fully malignant neoplasms. The derivation of these tumors remains uncertain: while some have suggested that these are tumors of muscle origin and others have postulated a neuroendocrine origin, the evidence accumulated to date is conflicting, and so these neoplasms continue to be regarded as tumors of uncertain origin. Surgical excision is the mainstay of therapy.

Alveolar soft part sarcoma of tongue base — A rare presentation of a rare tumor

“…ASPS are deceptively benign histologically with no atypical mitotic fi gures or nuclear pleomorphism. Demonstration of PAS-positive diastase-resistant crystals with the appropriate clinical history confi rms the diagnosis [5,7]. Cytogenetic analysis of soft part sarcomas consistently show the chromosomal translocation abnormality of der(17) t(X;17)(p11;q25) wherein 2 gene loci are involved, namely TFE3 (Location Xp11) and ASPSCR1 ( Location 17q25).…”

“…The incidence of metastases seems to be highest in the lungs (38%) followed by the brain (33%) It may present with multiple lymph nodes, presumably even while the sarcoma itself may be still small & undiagnosed. Cervical lymph node metastasis involvement occurs in about 7% of cases of head & neck ASPS [4,7]. Local recurrence after surgery has been reported in upto 20% of cases.…”

“…As a result of formalin fi xation, granular cells that are normally arranged in well-defi ned nests separated by a rich vascular network lose cohesion and create a pseudoalveolar pattern. These large cells may resemble gemistocytic astrocytes, atypical neurons, or metastatic renal cell carcinoma [7]. The nuclei of these tumor cells appear uniform and vesicular with prominent nucleoli showing the characteristic apple core concave indentation.…”

“…Although rare, dermoids of the tongue appear as hypoattenuated and well-circumscribed masses on CT images that may contain fat and typically show peripheral enhancement of the cystic wall. Squamous cell carcinoma of the tongue accounts for nearly one quarter of oral cavity cancer but typically does not have well-circumscribed borders, fl ow voids, intense enhancement, and hyperintense signal on T2-weighted images as seen in ASPS [2,4,7].…”

“…Chemotherapy is reserved for pulmonary metastasis. Prognosis is guarded, as 5-year and 20-year survival rates are reported to be 59% and 15%, respectively, with local recurrence and distant metastasis primarily responsible for the poor prognosis of this neoplasm [5,7,9].…”