2016 WHO Clinical Molecular and Pathological Criteria for Classification and Staging of Myeloproliferative Neoplasms (MPN) Caused by MPN Driver Mutations in the JAK2, MPL and CALR Genes in the Context of New 2016 WHO Classification: Prognostic and Therapeutic Implications.

The 2016 WHO-CMP classification proposal defines a broad spectrum of JAK2 V617F mutated MPN phenotypes: normocellular ET, hypercellular ET due to increased erythropoiesis (prodromal PV), hypercellular ET with megakaryocytic-granulocytic myeloproliferation and splenomegaly (EMGM or masked PV), erythrocythemic PV, early and overt classical PV, advanced PV with MF and post-PV MF. ET heterozygous for the JAK2 V617F mutation is associated with low JAK2 mutation load and normal life expectance. PV patients are hetero-homozygous versus homozygous for the JAK2 V617F mutation in their early versus advanced stages with increasing JAK2 mutation load from less than 50% to 100% and increase of MPN disease burden during life long follow-up in terms of symptomatic splenomegaly, constitutional symptoms, bone marrow hypercellularity and secondary MF. Pretreatment bone marrow biopsy in prefibrotic MPNs is of diagnostic and prognostic importance. JAK2 exon 12 mutated MPN is a distinct benign early stage PV. CALR mutated hypercellular thrombocythemia show distinct PMGM bone marrow characteristics of clustered larged immature dysmorphic megakaryocytes with bulky (bulbous) hyperchromatic nuclei, which are not seen in JAK2 mutated ET and PV. MPL mutated normocellular thrombocythemia is featured by clustered giant megakaryocytes with hyperlobulated stag-horn-like nuclei without features of PV in blood and bone marrow. Myeloproliferative disease burden in each of the JAK2, CALR and MPL MPNs is best reflected by the degree of anemia, splenomegaly, mutation allele burden, bone marrow cellularity and myelofibrosis.

Meningeal carcinomatosis in a patient with Crohn's disease.

Leptomeningeal carcinomatosis, also known as carcinomatous meningitis, is defined by spreading of neoplastic cells to the meninges and ventricles, and is a form of cancer dissemination. In this case, a patient with inflammatory bowel disease had developed a neoplastic process that spread to the meninges. A 49-year-old woman developed an abdominal pain, and was diagnosed the same month with Crohn's disease, complicated with intestinal perforation, for which she was hospitalized. Pathological examination revealed acute phase-terminal ileitis. She undergone many hospitalizations during which she was suspected to have celiac disease, inflammatory bowel disease, and tuberculous meningitis, as well as femoral head necrosis after she had been unsuccessfully treated with Prednisone for Crohn's disease. After she developed peripheral bilateral facial paresis, bilateral hypoacusia, hypotonia, tetraparesis and diminished osteotendinous reflexes at the legs, the patient was admitted in our department. Several lumbar punctures were performed but no specific disease could be detected. The MRI performed showed pachymeningeal and leptomeningeal inflammation. Tuberculous meningitis was taken into consideration and the patient was transferred into an Infectious Disease Department where this diagnostic was infirmed. The patient was retransferred into the Department of Neurology where after an episode of hematemesis she had a cardiac arrest and deceased. Inflammatory bowel disease may involve different segments of the intestine, and may be accompanied by a variety of conditions, such as neurologic findings, osteoarticular manifestations and also may be the starting point of a neoplastic process. The patient had an inflammatory bowel condition, which by the time it was appropriately diagnosed as being Crohn's disease, a neoplastic process spread to the meninges, causing multiple cranial nerve palsy, tetraparesis, along other neurological manifestations.