Introduction: Aggressive angiomyxoma are rare myxoid soft tissue neoplasms, affecting the pelvis and the perineum, rarely encountered in extragenital sites, with a marked preponderance for females in the reproductive age group. AAMs are thought to be benign, locally infiltrative and nonmetastasizing. Here is case report of AAM located in the posterior chest wall.Case report: 50-year-old female presented with complaints of swelling over the back since 1 year. Insidious in nature, clinically suspecting lipoma. MRI done gave an impression of cystic lesion likely to be a sebaceous cyst. Conclusion:AAMs are rare slow growing tumours with a high recurrence rate, seen almost exclusively in the pelviperineal region. The present case is unique in being located in the posterior chest wall. A histopathological examination, combined with radiological correlation, helped in distinguishing these lesions from the more commonly occurring similar entities, when they are located in sites other tan genital regions.