The bone marrow aspirate and biopsy in the diagnosis of unsuspected nonhematologic malignancy: A clinical study of 19 cases

Background: Although bone marrow metastases can be found commonly in some malignant tumors, diagnosing a nonhematologic malignancy from marrow is not a usual event. Methods: To underscore the value of bone marrow aspiration and biopsy as a short cut in establishing a diagnosis for disseminated tumors, we reviewed 19 patients with nonhematologic malignancies who initially had diagnosis from bone marrow. Results: The main indications for bone marrow examination were microangiopathic hemolytic anemia (MAHA), leukoerythroblastosis (LEB) and unexplained cytopenias. Bone marrow aspiration was not diagnostic due to dry tap or inadequate material in 6 cases. Biopsy results were parallel to the cytological ones in all cases except one; however a meticulous second examination of the biopsy confirmed the cytologic diagnosis in this patient too. The most common histologic subtype was adenocarcinoma, and after all the clinical and laboratory evaluations, the primary focus was disclosed definitively in ten patients ( 5 stomach, 3 prostate, 1 lung, 1 muscle) and probably in four patients ( 3 gastrointestinal tract, 1 lung). All work up failed in five patients and these cases were classified as tumor of unknown origin (TUO). Conclusion: Our series showed that anemia, thrombocytopenia, elevated red cell distribution width (RDW) and hypoproteinemia formed a uniform tetrad in patients with disseminated tumors that were diagnosed via bone marrow examination. The prognosis of patients was very poor and survivals were only a few days or weeks ( except for 4 patients whose survivals were longer). We concluded that MAHA, LEB and unexplained cytopenias are strong indicators of the necessity of bone marrow examination. Because of the very short survival of many patients, all investigational procedures should be judged in view of their rationality, and should be focused on treatable primary tumors.