In the sentence extracted from biomedical literature, identify all the disease entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="disease"> to denote a disease.

### Input Text: A major cytogenetic subgroup of lipomas is characterized by recurrent chromosome aberrations , mainly translocations , that involve chromosome segment 12q13 - q15 .
### Output Text:
A major cytogenetic subgroup of <span class="disease">lipomas</span> is characterized by recurrent chromosome aberrations , mainly translocations , that involve chromosome segment 12q13 - q15 . 