Characteristics of the recent largest published series of MH
| Series of patients . | No. of primary/secondary MH . | No. of localized/disseminated disease . | Previous or associated hematologic neoplasm . | KRAS, NRAS, BRAF, or MAP2K1 mutation . | PTPN11 mutation∗ . | |||
|---|---|---|---|---|---|---|---|---|
| ALL/lymphoma . | Mature B-cell lymphoma . | Other . | In primary . | In secondary . | ||||
| Boston, MA18 | 23/5 | 19/9 | 2 (2B) | 2 | 1 | 9/24 | 3/4 | 2/24 |
| NIH, Bethesda, MD16,17 | 21/16 | Not available | 6 (4T & 2B) (2 children) | 10 | 0 | 13/21 | 13/16 | 4/21 |
| Rochester, MN and Birmingham, AL†,14,15 | 30/12 | 10/32 | 1 (1B) | 9 | 2 | 9/16 | 5/5 | 2/16 |
| Total of published series | 74/33 (primary 69%) | 29/41 (localized 41%) | 9 | 21 | 3 | 31/61 (51%) | 21/25 (84%) | 8/61 (13%) |
| Present series | 90/51 | 44/91 (localized 33%) | 11 | 21 | 7 | 22/40 (55%) | 28/31 (90%) | 10/37 (27%) |
| Total | 164/66 (primary 71%) | 73/132 (36%) | 20 | 42 | 10 | 53/101 (52%) | 49/56 (88%) | 18/98 (18%) |
| Series of patients . | No. of primary/secondary MH . | No. of localized/disseminated disease . | Previous or associated hematologic neoplasm . | KRAS, NRAS, BRAF, or MAP2K1 mutation . | PTPN11 mutation∗ . | |||
|---|---|---|---|---|---|---|---|---|
| ALL/lymphoma . | Mature B-cell lymphoma . | Other . | In primary . | In secondary . | ||||
| Boston, MA18 | 23/5 | 19/9 | 2 (2B) | 2 | 1 | 9/24 | 3/4 | 2/24 |
| NIH, Bethesda, MD16,17 | 21/16 | Not available | 6 (4T & 2B) (2 children) | 10 | 0 | 13/21 | 13/16 | 4/21 |
| Rochester, MN and Birmingham, AL†,14,15 | 30/12 | 10/32 | 1 (1B) | 9 | 2 | 9/16 | 5/5 | 2/16 |
| Total of published series | 74/33 (primary 69%) | 29/41 (localized 41%) | 9 | 21 | 3 | 31/61 (51%) | 21/25 (84%) | 8/61 (13%) |
| Present series | 90/51 | 44/91 (localized 33%) | 11 | 21 | 7 | 22/40 (55%) | 28/31 (90%) | 10/37 (27%) |
| Total | 164/66 (primary 71%) | 73/132 (36%) | 20 | 42 | 10 | 53/101 (52%) | 49/56 (88%) | 18/98 (18%) |
CNS, central nervous system; ECD, Erdheim-Chester disease; NIH, National Institutes of Health.
PTPN11 mutations were detected only in primary MH.
Case 4915 is excluded because MH is indicated as secondary to ECD of the brain. There are no consensual criteria for diagnosis of ECD exclusively localized to CNS, and it seems difficult to exclude that it could not be MH of the CNS. Detection of a new somatic alteration in MH sample absent in an ECD sample would have been helpful.