Table 1.
Clinical characteristics of the patients
| Case no. |
Age (years)/Sex | Revelatory symptom | Peritoneal involvement (mass/diffuse) | Surgical/Needle biopsy | First proposed histological diagnosis | Mutational status | Final diagnosis | Time delay until final diagnosis (months)* | Other organs involved | Evolution, status (months after biopsy) |
| 01 | 73/M | Abd pain | Diffuse | Needle | Inflammation | WT* | ECD | 7 | Bones, r&pr, | AWD (21) |
| 02 | 17/M | Peripheral oedema | Diffuse | Surgical | ECD | MAP2K1 | ECD | 51 | r&pr, heart, kidney, testis | AWD (24) |
| 03 | 54/M | Abd pain | Mass (3 cm) | Surgical | ECD | WT* | Sclerosing mesenteritis | 6 | No | AWD (0) |
| 04 | 79/M | Abd pain | Mass | Surgical | Sclerosing mesenteritis | WT | Sclerosing mesenteritis | 5 | No | AWD (6) |
| 05 | 60/F | Abd pain | Mass | Surgical | ECD | WT, NF1 | Sclerosing mesenteritis | 5 | No | AWD (30) |
| 06 | 75/F | Anaemia | Mass | Surgical | Inflammation | WT* | Histiocytosis NOS | 2 | No | Postop death |
| 07 | 55/M | Ischaemic cardiopathy | Diffuse | Surgical | ECD | BRAF | ECD | 49 | Mediastinum | DOD |
| 08 | 43/M | Fever | Mass | Surgical | ECD | BRAF | ECD | 9 | r&pr, bones | No follow-up |
| 09 | 63/M | Asymptomatic | Mass | Surgical | Fibrosis | WT* | ECD | 9 | Kidney, bones | AWD |
| 10 | 36/M | Abd pain | Mass | Surgical | Sclerosing mesenteritis | BRAF | ECD | 53 | Exophthalmia, skin, kidneys, bones | AWD (90) |
| 11 | 71/M | Abd pain | Mass (15 cm) | Needle | Sclerosing mesenteritis | BRAF | ECD | 15 | CNS, periaortic, r&pr | AWD (12) |
| 12 | 44/F | Bone pain | Mass (11 cm) | Surgical | ECD | BRAF | ECD | 4 | Bones | AWD (8) |
| 13 | 36/F | Abd pain | Diffuse | Surgical | Liposarcoma | WT* | Histiocytosis NOS | 28 | Liver, bone marrow | DOD |
| 14 | 73/M | Fever, asthenia | Diffuse | Surgical | Inflammation | BRAF | ECD | 3 | Bones, bone marrow | AWD (10) |
| 15 | 68/F | Weight loss | Diffuse | Surgical | Inflammation | BRAF | ECD | 2 | Bones, r&pr, CNS | AWD (45) |
| 16 | 54/M | Abd pain | Diffuse | Surgical | Inflammation | BRAF | ECD | 23 | Mediastinum | DOD (72) |
| 17 | 58/M | Asymptomatic | Mass (4 cm) | Needle | Sclerosing mesenteritis | WT* | Sclerosing mesenteritis | 27 | No | AWD (2) |
| 18 | 66/M | Abd pain | Diffuse | Surgical | ECD | MAP2K1 | ECD | 3 | Bones, heart, CNS | DOD (17) |
| 19 | 72/M | Abd pain | Diffuse | Surgical | ECD | BRAF | ECD | 49 | Bones, heart, orbit, aorta | DOD (33) |
| 20 | 51/F | Asymptomatic | Diffuse | Surgical | Inflammation | WT | Xanthogranulomatous peritonitis | 17 | No | AWD (2) |
| 21 | 66/M | Xanthelasma, retroperitoneal fibrosis | Diffuse | Surgical | Inflammation | BRAF | ECD | 23 | Liver‡, spleen, bones, r&pr, pericardium, retroorbital, skin | AWD |
| 22 | 54/M | General state alteration | Mass (13 cm) | Surgical | ECD | BRAF | ECD | 6 | Liver‡, spleen, bones, r&pr, pericardium | AWD (9) |
Patients 2 and 7 have mixed histiocytoses (ECD/RDD and ECD/Langerhans cell histiocytosis, respectively). Patient 11 had an associated chronic myelomonocytic leukaemia, patient 14 had an associated MDS and patient 7 developed a MDS during follow-up.
*Time between the first symptom (or, where we do not have the information, the date of the first peritoneal biopsy) and the diagnosis of histiocytosis.
†Molecular analysis limited to BRAFV600E, because of the low amount/quality of DNA obtained from the involved tissue.
‡Hepatomegaly.
Abd, abdominal; AWD, alive with disease; CNS, central nervous system; DOD, deceased of disease; ECD, Erdheim-Chester disease; F, female; M, male; MDS, myelodysplastic syndrome; NOS, not otherwise specified; RDD, Rosai-Dorfman disease; r&pr, retroperitoneal and perirenal; WT, no mutation of the genes of the MAP kinase pathway detected.