Adenoid Cystic CA: Prognosis
Adenoid cystic carcinoma is an indolent but highly aggressive tumor that pursues a relentess course. The long-term prognosis is poor. The prognosis is highly dependent upon pattern of growth (i.e. histologic grade). The 15-yr survival rates for Grades 1, 2, and 3 are 39%, 26%, and 5% respectively. Other prognostic factors include clinical stage, margins of resection, tumor location, tumor size, and lymph node metastases. The majority of patients (80-95%) eventually succumb to the tumor within 10-15 years after diagnosis. The protracted clinical course is punctuated by multiple recurrences and metastases. Distant metastases occur 5 to 10 years after initial treatment. The usual sites are lung (most common), liver, bone, brain, and soft tissues. The pulmonary metastases are frequently asymptomatic. Regional lymph node metastases are comparatively rare. The image shows a focus of squamous metaplasia in an adenoid cystic carcinoma that underwent de-differentiation (same case as the previous seven images).