Table 1.
M group malignant histiocytoses secondary to preceding lymphoid neoplasms
| Sequenced tumor diagnosis (case) | Age, yr (sex) | Reported prior malignancy | MAPK alteration | Identified mutations associated with prior malignancy | Mutations uncommon in prior malignancy | Confirmed clonality |
|---|---|---|---|---|---|---|
| Histiocytic sarcoma (69) | 4 (M) | T‐ALL | KRAS | ARID1A, PTEN, CDKN2A, CDKN2B | Prior not tested | |
| Histiocytic sarcoma (47) | 25 (M) | T‐ALL | BRAF | NOTCH1, PTEN, CDKN2A, CDKN2B | Prior not tested | |
| Histiocytic sarcoma (81) | 1 (M) | T‐ALL | BRAF | MYC (rearrangement), CDKN2A | Shared MYC rearrangement | |
| Histiocytic sarcoma (57) | 38 (M) | B‐ALL | NF1 | SETD2, PAX5, CDKN2A, CDKN2B | Prior not tested | |
| Histiocytic sarcoma (85) | 14 (M) | B‐ALL | NRAS | NRAS a | Shared NRAS variant | |
| Histiocytic sarcoma (80) | 78 (F) | Diffuse large B‐cell lymphoma | BRAF | TNFAIP3, TET2, CARD11, CDKN2A, CXCR4 | Prior not tested | |
| Histiocytic sarcoma (83) | 70 (F) | Diffuse large B‐cell lymphoma | NRAS | CREBBP, EP300, STAT3, CDKN2A, PTEN | CUX1 b | Prior not tested |
| Histiocytic sarcoma (60) | 62 (F) | Follicular lymphoma | BRAF | IGH/BCL2 (rearrangement), CREBBP, KMT2D, ARID1A | PTEN, SMARCA4, CDKN2A, CDKN2B, ASXL2, DNMT3A | Shared clonal IgH rearrangement |
| Histiocytic sarcoma (78) | 66 (F) | Follicular lymphoma | KRAS | TNFAIP3 | DNMT3A, CEBPA | Prior not tested |
| Interdigitating dendritic cell sarcoma (92) | 22 (M) | B‐ALL | NRAS | NRAS, a TP53 | Shared clonal IgH rearrangement | |
| Langerhans cell sarcoma (99) | 66 (F) | B‐cell lymphoma (NOS) | MAP2K1 | IGH/BCL2 (rearrangement), CARD11, SF3B1, TNFAIP3, HIST1HD, TNFRSF14, FAS | CDKN2A, CDKN2B, PTEN | Prior not tested |
| Langerhans cell sarcoma (100) | 71 (F) | Small B‐cell lymphoma c | KRAS | CREBBP, KLF2, KMT2D | CDKN2A, FBXW7 | Prior not tested |
| Langerhans cell sarcoma (102) | 65 (F) | Follicular lymphoma | MAP2K1 | KMT2D, CARD11, CREBBP, BCL2 (rearrangement) | PTEN | Prior not tested |
Variants of undetermined significance are not shown.
a
NRAS gain‐of‐function mutations are common in B‐ALL.
b
CUX1 loss; diffuse large B‐cell lymphoma may show CUX1 gain of copy alterations.
c
The patient's submitted history was lymphoplasmacytic lymphoma; however, the presence of a KLF2 mutation and absence of MYD88 mutation in the patient's LCS would favor a preceding splenic marginal zone lymphoma.
Abbreviations: B‐ALL, B‐lymphoblastic leukemia/lymphoma; F, female; M, male; T‐ALL, T‐acute lymphoblastic leukemia.