Chapter 63: Chest Wall Tumors

INTRODUCTION

Chest wall tumors are a rare collection of benign and malignant tumors involving the various layers of the thorax. Primary chest wall tumors constitute approximately 1% of all tumors. Of chest wall tumors, approximately half are benign, and half malignant. Management varies based on tumor type and risk of malignancy. Given the rare nature of chest wall tumors, formal guidelines for their management are lacking. However, review of past management practice as well as ongoing experience in chest wall tumor management has resulted in cumulative experience with which we approach chest wall tumors.

The incidence of different chest wall tumor types is variously reported in a limited number of case series. We have reported estimated incidence of more commonly occurring chest wall tumors based on the currently available series from the past three decades.^1-5 Estimating incidence has been further complicated by reclassification of different tumors over the decades. As a result, the true incidence of chest wall tumors, as currently defined, is unclear.

Regarding the periodic and ongoing reclassification of chest wall tumor types, we have identified the following situations which the reader should be aware of. Fibrosarcoma was the most common soft tissue sarcoma (STS) reported in the first half of the 20th century.⁶ A review of fibrosarcomas by Stout in 1948 revealed that many tumors classified as such were actually rhabdomyosarcomas, liposarcomas, and synovial sarcomas.⁷ Malignant fibrous histiocytoma (MFH) was subsequently the most common soft tissue tumor type in adults starting in the 1960s. Modern pathologic review of MFH series reveal that many tumors previously identified as MFH have been reclassified as pleomorphic sarcomas originating from different tissue types.⁸ MFH is now renamed undifferentiated pleomorphic sarcoma and accounts for a much smaller percentage of STS than previously thought.⁹ Similarly, desmoid tumor was previously classified as low-grade fibrosarcoma but is now widely regarded as borderline malignant tumor with no metastatic potential.⁶ Reported series of primary chest wall tumors necessarily suffer from this same pathologic confusion as they have been collected over decades owing to the rarity of these tumors. In estimating the incidence of primary chest wall tumors we attempt to use modern pathologic designations whenever possible (Table 63-1).

Benign and malignant tumors each constitute approximately 50% of primary chest wall tumors.^3,10 It is estimated that half of all malignant tumors ...