51, male. JAK2 mututation confirmed with no other mutations of concern as per NGS. Three years ago, based on my BMB and high platelets I was diagnosed a differential diagnosis with includes prefibrotic primary myelofibrosis versus essential trhombocythemia. Recently, through what seemed a rather rushed second opinion to qualify for a trial.
The first BMB, in 2023 concluded (by an international MPN expert) the differential diagnosis includes a prefibrotic primary myelofibrosis, versus essential thrombocythemia.
First BMB
The marrow appears hypercellular for age (approximately 60-70% cellular overall). The myeloid to erythroid ratio appears somewhat increased. Myeloid and erythroid maturation are complete. Megakaryocytes are increased in number, vary in size, including large forms. Many show nuclear atypia with hyperlobation, atypical nuclear morphology, and hyperchromasia with frequent clustering. A reticulin stain shows a patchy mild increase in reticulin fibers (MF0 to MF1). A trichrome stain shows no definite collagen fibrosis.
The missing clinical piece was LDH, otherwise based on WHO criteria I would be PMF. Recently my LDH went over 283 and more recently close to 400.
Second BMB last month
No major changes. MF 0-1, mostly grade 0, < 20% grade 1 (by reticulin and trichrome staining). Megakaryocytes Cellularity: hypercellular Morphology: variable in size: pleomorphic, few large megakaryocytes with hyper lobulation without the morphology of staghorn cells, rare megakaryocytes with hyperchromatic nuclei, and cloud-like nuclei. Few loose clusters, Confirmed by factor 8.
There was no evidence of panmyelotic marrow pattern with clear erythoid hperplasia.
My blood work is as follows:
- Sep 06, 2024: Hgb 155 g/L | Hct 0.455 L/L | Plt 771 | MCV 88.9 fL | Ferritin 104 ug/L
- Dec 03, 2024: Hgb 162 g/L | Hct 0.487 L/L | Plt 802 | MCV 88.5 fL | LDH 206 u/L | EPO 3.1 mIU/mL | Ferritin 88 ug/L
- Jan 21, 2025: Hgb 155 g/L | Hct 0.460 L/L | Plt 790 | MCV 87.5 fL | LDH 235 u/L | Ferritin 116 ug/L
- Apr 22, 2025: Hgb 163 g/L | Hct 0.487 L/L | Plt 832 | MCV 88.9 fL | LDH 210 u/L | Ferritin 112 ug/L
- Aug 05, 2025: Hgb 153 g/L | Hct 0.460 L/L | Plt 753 | MCV 91.3 fL | LDH 247 u/L | Ferritin 59 ug/L
- Dec 16, 2025: Hgb 161 g/L | Hct 0.480 L/L | Plt 821 | MCV 90.4 fL | LDH 227 u/L | Ferritin 99 ug/L
- Mar 10, 2026: Hgb 165 g/L | Hct 0.490 L/L | Plt 822 | MCV 91.2 fL | LDH 243 u/L | Ferritin 75 ug/L
- Apr 10, 2026 (Spike): Hgb 171 g/L | Hct 0.51 L/L | Plt 821 | MCV 89.5 fL | LDH 289 U/L | EPO 2.3 mIU/mL (Urea 10.4 | Urine SG ≥ 1.030) (BMB Iron: Decreased)
- Apr 20, 2026 (Retreat): Hgb 157 g/L | Hct 0.45 L/L | Plt 836 | MCV 87.6 fL | LDH 358 u/L
- Apr 24, 2026 (Stabilization): Hgb 159 g/L | Hct 0.47 L/L | Plt 831 | MCV 89.6 fL
The pathologist looked at a blip on a recent blood draw where I was very dehydrated to the point I flagged it to the nurse taking the blood sample (some extreme personal circumstances). Urine analysis on that day seems to corroborate with dehydration. HCT and Hemoglobin momentarily spiked on one draw and quickly went down days later. Yet as result of the low EPO 2.3 from the BMB (previous 3.1) and the "decrease" in iron stores along with the one day HCT spike and Hemoglobin spike the diagnosis of PMF or ET was refuted. And suspicion that it was masked PV and was deemed unclassified because BMB could not back PV.
I'm really demoralized. Yes PV is less serious than PMF in some ways. But being stuck in limbo Unclassified means my insurance will not cover for Besremi up here in Canada.
Questions
Anyone else in Unclassified limbo? Any tips on how to best navigate this moving forward other than a second opinion? Unfortunately this is going to cost me as I'm not eligible for a trial I was counting on and despite originally getting second opinions to avoid the unclassified designation find myself there again
Can anyone comment on any of the above info? Does low EPO (40% ET have it but they said that it was very low and more like PV) and low iron stores account for this? I'm on a plant diet and started taking calcium supplements and wondered if that impacted EPO.
The HCT and Hemoglobin blip seems to be impacting the diagnosis where it otherwise was under the WHO criteria. I was dehydrated that day and wondering if that impacted the measure.
Going from you are missing LDH but otherwise you are officially PreMF based on WHO to your HCT and Hemoglobin went over the threshold once even though stabilized so its not preMF seems unreasonable. Wondering if anyone had similar experiences with masked PV.