Does morphology matter in 2017? An approach to morphologic clues in non‐neoplastic blood and bone marrow disorders

Abstract

Numerous non-neoplastic and neoplastic conditions manifest with distinctive features in blood. Although automated complete blood count (CBC) data are essential, CBC information alone is insufficient for diagnosis. Consequently, morphologic review of blood smears is still relevant in the era of sophisticated automated analyzer systems.Pathologist interpretation of the peripheral blood smear, in conjunction with CBC and clinical information, can provide rapid diagnostic information and guide cost-effective targeted laboratory testing. Pathologist review of blood smears can be used to diagnose cases in which the clinical findings are misleading or nonspecific. Here, we discuss a selection of cases in which the pathologist examination of the blood smear can aid in rapid and accurate diagnosis and guide appropriate treatment. Exemplary nonneoplastic disorders with distinctive morphologic blood features of RBC, neutrophils, monocytes, and lymphocytes will be highlighted. The differential diagnostic considerations in blood smears with RBC destruction will be presented, expanding beyond microangiopathic hemolytic anemia. Lymphocyte morphologic assessment guides differential diagnosis including the identification of rare germline disorders. In each case presented, the integration of morphologic features guided additional testing with confirmation of the diagnosis. Peripheral blood smear review is timely and cost effective, even in an era of sophisticated automated laboratory testing.

Optimizing morphology through blood cell image analysis

“…External quality control programs have highlighted difficulties to differentiate between leukemic and non‐neoplastic cells, the abnormal lymphoid cells being the most difficult to identify by the participants . With respect to lymphoid neoplasms, few studies have been published regarding feature analysis in abnormal lymphoid cells.…”

An evaluation of existing manual blood film schistocyte quantitation guidelines and a new proposed method

“…The thrombotic microangiopathies (TMA) are a broad range of conditions with differing clinical features, aetiologies and prognoses, some of which require immediate recognition and therapy. [1][2][3][4][5][6][7][8][9][10][11] This is best exemplified by thrombotic thrombocytopenic purpura (TTP), which is a medical emergency. TTP is caused by deficiency in a disintegrin and metalloproteinase with a thrombospondin Type 1 motif (ADAMTS13).…”

“…The time critical recognition and treatment of TTP and other TMAs relies on the timely detection of red cell schistocytes on manual examination of the blood film. [5][6][7]9,10,12,13 The unifying features of TMA are small vessel wall injury and microthrombosis, presenting with a microangiopathic haemolytic anaemia (MAHA) and thrombocytopenia. 9,14 Schistocytes are the morphological hallmark of the mechanical haemolysis of MAHA.…”

“…2,5,9 Schistocytes may be seen in other conditions not related to microangiopathy, including haematological malignancy, prosthetic heart valves, megaloblastic anaemia, renal failure, iron deficiency and thalassemia. 5,8,10,16,18 In this context they are not the predominant erythrocyte abnormality, comprising only a minor component of a more global aniso-poikilocytosis. 2,4,5,8,10,18 Here, the significance of schistocytes on the blood film is much reduced.…”

Comparison between optical microscopy and the Sysmex XN‐3000 for schistocyte determination in patients suspected of having schistocytosis

“…In the past, automated machines could not accurately determine blood cells with abnormal morphology and, therefore, every flagged result from an automated device required confirmation by a clinician or technologist . However, this manual approach to schistocyte determination has limitations in routine clinical practice, including a lack of intra‐ and interdepartmental standardization, the fact that it is time‐consuming—as argued by Lesesve—and the fact that confirmation needs to be made by a highly experienced physician . In patients suspected of having TTP, a lack of availability of experienced personnel for microscopy scoring could cause delays in both diagnosis and treatment, which could lead to unfavourable outcomes.…”