LOW-LEVEL CHROMOSOME-12 AMPLIFICATION IN A PRIMARY LIPOMA OF THE LUNG- EVIDENCE FOR A PATHOGENETIC RELATIONSHIP WITH COMMON ADIPOSE-TISSUETUMORS

Cytogenetic analysis of a primary lipoma of the lung removed from a 56 -year-old woman revealed the presence of a supernumerary marker chromo some in all metaphase cells analyzed; namely, 47,XX,+mar. To the best of our knowledge, this is the first cytogenetic description of a prima ry lipoma of lung. Genetic analysis of intramuscular lipoma, atypical lipoma, and well-differentiated liposarcoma have revealed the presence of one to three supernumerary ring or giant marker chromosomes compos ed of chromosome 12 segments as the characteristic anomaly. The marker chromosome in the present case was shown to be composed entirely of c hromosome 12 material by subsequent analysis with a chromosome 12-spec ific paint probe and fluorescence in situ hybridization. Thus, analogo us to intramuscular lipoma, atypical lipoma, and well-differentiated l iposarcoma, extra chromosome 12 material is present. These findings su pport a pathogenetic relationship between this lipoma of unusual anato mic location and common adipose tissue tumors.