Priority for Description of the MELF Pattern of Myoinvasive Endometrioid Carcinoma
We much enjoyed the outstanding paper by Joehlin-Price et al1 recently published in the Journal on the MELF pattern of myoinvasive endometrioid carcinoma. A very detailed study which further contributes to the literature on a fascinating aspect of endometrioid carcinoma which perhaps surprisingly escaped attention until we described the phenomenon in 2003.2 We were surprised to see that in the first paragraph of their introduction, when the background of this pattern of neoplasia is referred to, it stated that “this morphologic pattern was initially recognized by Lee et al.” With respect, that is not historically accurate as the paper of Lee et al3 does not in a meaningful way note the MELF pattern.
The background is as follows. When one of us (S.K.M.) was a visiting fellow at the Massachusetts General Hospital working under the supervision of the second author (R.H.Y.), we were struck by seeing in a relatively short period of time a few cases of invasive endometrioid carcinoma in which we noted distinctive microcystic glands which were often elongated and fragmented and frequently associated with a prominent fibromyxoid stroma. Dr Robert E. Scully was retired at the time but we sought his assistance and this was one of the last papers he co-authored in his illustrious career.4 He had countless attributes as have been pointed out in the essay on him just cited. One was a great knack for coming up with names and acronyms and he came up with the now well-known acronym “MELF.” As a side comment it has been recently suggested to us that the F should stand for fibromyxoid rather than fragmented but although a stromal alteration is typical of the MELF pattern one may see a fibromyxoid stroma with other patterns of myoinvasive carcinoma and it is the constellation of the microcystic glands (M), often elongated (EL), and fragmented (F), which is the unique triad of this entity. Dr Scully was also fastidious about those who trained under him, as we were fortunate to do, carefully going over the prior literature to make sure that observations of others were duly noted. We did so in this instance and were not able to find any specific description of the pattern. We did find in the paper of Lee et al3 an illustration that suggests it might have been an elongated MELF gland but it was not so characterized in the paper; we did nonetheless cite their paper. Lee and colleagues did not describe microcystic glands or fragmentation or make any particular comment on the elongated glands. We are pleased that Joehlin-Price and other authors have written so many good papers on this intriguing neoplastic pattern which is not only morphologically interesting but is of clinical import.