Multiple clonal chromosome aberrations in a case of childhood focal nodular hyperplasia of the liver.

A case of focal nodular hyperplasia is described that was accompanied by intense reactive stromal changes giving rise to a pseudosarcomatous appearance. Cytogenetic study revealed complex karyotypic abnormalities including five partially identifiable clonal aberrations and one marker chromosome. The composite karyotype was interpreted as: 45–46,XY,add(4)(q21–25)[24], add(11)(p14)[24],add(19)(p13) [15],der(20)t(1;20)(q25;p12)[31],add(21)(q22)[13],-22[3], +mar[2][cp31]. In addition, quadriradial or complex figures, telomeric associations tas, unidentified ring chromosomes, chromosome breaks, and markers were seen in some cells. Such cytogenetic findings, although suggestive of malignancy, could most likely be related to a nonneoplastic condition, i.e., the unusual florid reactive changes associated with this focal nodular hyperplasia.