The spelling of "mesenchymal hyloma" can be a bit tricky. "Mesenchymal" is pronounced /ˌmɛzɛŋˈkaɪməl/ and refers to cells that can form connective tissue, while "hyloma" means a mass or lump and is pronounced /haɪˈloʊmə/. Together, they refer to a type of tumor that arises from mesenchymal tissue. The word may be difficult to spell, but understanding its phonetic transcription can help with both pronunciation and comprehension.
A tumor of tissue derived from the mesoblastic pulp or mesenchyme.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.