Alveolar Soft Part Sarcoma: Clinical, Histopathological, Molecular, and Ultrastructural Aspects

Abstract

Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor occurring mainly in the adolescents and young adults. Multimodality treatment has not been effective, and excision remains the mainstay of treatment. Histopathologically, it varies little from case to case. It is composed of organoid aggregates of large polygonal cells with vesicular nuclei and abundant granular, eosinophilic cytoplasm, separated by delicate vascular channels. The line of differentiation of this unique tumor is yet undetermined, although recent advances have led to a better understanding of the genetic events underlying the pathogenesis of this tumor. The histopathological, ultrastructural, immunohistochemical, and genetic aspects of ASPS are discussed.

Orbital alveolar soft part sarcoma: A report of 8�cases and review of the literature

“…As with other space-occupying lesions in the orbit, patients with ASPS primarily present with proptosis, abnormal position of the eyes, eyelid swelling, and conjunctival congestion with dilated and tortuous vessels ( 16 ). In certain cases, metastasis to the lungs or brain may be the presenting feature of ASPS ( 44 ).…”

Clavicular and meningeal alveolar soft part sarcoma: An unusual case and literature review

“…Typically, prominent, periodic acideSchiff (PAS) positive, diastase-resistant crystals and granules are seen. 15,16 Initial studies of these cytoplasmic granules reported protein and polysaccharide complexes. 16 Further experimentation has found an accumulation of MCT1-CD147 complexes, as CD147 has two potential TFE3 binding sites (the transcription factor which was translocated), this overproduction could be related to the novel genetic sequence of ASPS; however, further transactivation assays need to be performed.…”

Tumors of a Granular Cell Lineage

“…Histologically, the pattern is uniform and characterized by groups or compartments of cells, these structures being separated from each other by thin-walled vascular channels and matrix septa, resulting in a (pseudo)alveolar-like image giving the tumor its name. This alveoloid pattern is furthermore promoted by loss of cell adhesion and thus gap formation caused by regressive changes commonly occurring in the center of the cellular compartments (Weiss and Goldblum 2001;Khanna et al 2008). At the periphery of the lesion, abnormal and dilated blood vessels are a typical feature, and angioinvasion is typical for this neoplasm.…”