On the Resurgence of the Hematologist as Consultant to Primary Care Practitioners.
Authors: Sinha Sudha , Trainor Brian , Weinstein Robert 
Published: April 2020

Abstract
The widespread use of “routine” automated blood testing in primary care practice appears to have increased the demand for consultative services by hematologists. To explore this hypothesis, we tracked consecutive first-time referrals to our university hospital hematology clinic retrospectively between July 2002 and June 2003 and prospectively from July 2003 to May 2004. Findings were similar in both time intervals and thus are combined for reporting. Of 557 consultative referrals, 326 patients (58.5 %) were referred for abnormalities of the peripheral blood counts, 209 (64%) of which were detected as incidental findings in asymptomatic patients. 144 (26%) of all referrals were for anemia and 79 (55%) of those proved to have primary medical conditions including active alcoholism, medication effects, chronic renal failure, iron deficiency, chronic inflammatory diseases or advanced liver disease. The rest had hematological disorders including, myelodysplastic syndromes, hemoglobinopathies, hemolytic anemias, and others. 66 (12%) of all referrals were for abnormalities of the white blood cell count and only 24 (36%) turned out to have a primary hematological disorder (e.g. CLL, CML or benign chronic leukopenia). The other 42 (64%) had primary medical disorders including leukocytosis of smoking or pregnancy, allergies, anti-convulsant-related leukopenia, etc. 50 patients were referred for thrombocytopenia or thrombocytosis, of which 29 (58%) had primary medical disorders including iron deficiency or inflammatory states, gestational thrombocytopenia, known hypersplenism, medication-related thrombocytopenia, or alcoholism. Similarly 20 of the 40 patients referred for bi- or pancytopenias had primary hematological disorders and 20 had medical disorders that included hypersplenism, drugs, or mild disorders that resolved by the time of referral. The remaining 231 patients (41.5%) included 69 who were referred for evaluation of, and counseling for, hypercoagulable disorders, 39 referred for presumed bleeding disorders (4 had senile purpura; 9 had storage pool disorders), 9 with hereditary hemochromatosis, 51 with hematological malignancies, 12 with unexplained lymphadenopathy (8 with infectious mononucleosis or other reactive lymphadenopathy, 1 with enlarged tonsils, 1 CLL, 1 T-cell lymphoma, 1 Kimura’s disease) and 9 patients with polyclonal hyperglobulinemia. Overall, only 45 % of the patients referred for consultation turned out to have a primary hematological disorder. The rest had conditions that are traditionally considered to be in the realm of internal medicine or primary care. Most consults were initiated based on incidental abnormalities of the CBC that were not, or could not be, worked up by the referring physician. Thus primary care practitioners are relying on hematologists to explain routine findings in often-asymptomatic patients with fortuitous abnormalities of the peripheral blood counts. Medical surveillance of asymptomatic patients is likely to result in progressively early detection of subtle changes in the CBC that internists and others will rely on hematologists to explain. Thus the hematologist’s role as consultant continues to expand.