The search yielded nine cases of coexistent MPN and LPD out of a total of 269 patients diagnosed with BCR-/ABL1-negative MPN (244) or an MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasms (25)) and 1062 patients diagnosed with an LPD. This evidence concerns the gene BCR and disseminated peritoneal leiomyomatosis.