The spelling of the word "archoptoma" can be explained using IPA phonetic transcription. The word can be broken down into three syllables: arch-op-to-ma. The first syllable, "arch", is pronounced with the /ɑːr/ sound, like in "car". The second syllable, "op", is pronounced with the /ɒp/ sound, like in "hop". The third syllable, "to-ma", is pronounced with the /təʊmə/ sound, like in "tomahto". So, the proper spelling of the word is "archoptoma".
Archoptosia.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.