LESIONS OF 13Q MAY OCCUR INDEPENDENTLY OF DELETION OF 16Q IN SPINDLE-CELL PLEOMORPHIC LIPOMAS

Aims: Very recent multidisciplinary investigations have allowed for th e definition among lipomas of a clinical and histological subtype call ed spindle cell and/or pleomorphic lipoma, possibly associated with pa rtial monosomy 16 and anomalies of chromosome 13, In order to get near er to the underlying critical molecular changes further multidisciplin ary pathological and genetic research is indicated, to identify which chromosome(s) anomalies are crucial in the development of these tumour s. Methods ann results: In an ongoing multidisciplinary study of lipom atous tumours, including clinical findings, morphology, histochemistry and cytogenetics, two instances were found of spindle cell lipoma wit h clonal chromosome changes, In both cases chromosome 13 was involved, whereas only one showed a partial monosomy 16. Conclusions: Partial m onosomy 16 is a characteristic lesion in spindle cell lipoma, usually associated with anomalies of chromosome 13, The present report confirm ing a previous single observation indicates, however, that lesions of 13 may occur independently from lesions of 16, suggesting different un derlying molecular lesions in these otherwise very similar lipomas.