Volumetric Splenomegaly in Patients With Polycythemia Vera

Abstract

Background Non-palpable splenomegaly in patients with polycythemia vera (PV) has seldom been addressed. In this retrospective study, we evaluated non-palpable, volumetric splenomegaly defined based on age- and body surface area (BSA)–matched criteria in patients with PV diagnosed according to the 2016 World Health Organization diagnostic criteria. Methods Patients with PV who underwent abdominal computed tomography (CT) and who had palpable splenomegaly at diagnosis from January 1991 to December 2020 at Chungnam National University Hospital were enrolled. The spleen volume of each patient was determined by volumetric analysis of abdominal CT and adjusted for the patient’s age and BSA. Then the degree of splenomegaly was classified as no splenomegaly, borderline volumetric splenomegaly, overt volumetric splenomegaly, or palpable splenomegaly. Results Of the 87 PV patients enrolled, 15 (17.2%) had no splenomegaly, whereas 17 (19.5%), 45 (51.7%), and 10 (11.5%) had borderline volumetric, overt volumetric, and palpable splenomegaly, respectively. The degree of splenomegaly did not affect the cumulative incidence of thrombotic vascular events (10-year incidence: 7.7%, 0%, 22.3%, and 50.7%, respectively, P = 0.414). By contrast, splenomegaly tended to adversely affect myelofibrotic transformation (10-year cumulative incidence: 0%, 0%, 7.1%, and 30.3%, respectively, P = 0.062). Moreover, the cumulative incidence of myelofibrotic transformation was significantly higher in patients with overt volumetric or palpable splenomegaly than those with no or borderline volumetric splenomegaly (10-year incidence: 0% vs. 10.3%, respectively; 15-year incidence: 0% vs. 26.3%, respectively, P = 0.020). Overall survival (OS) differed among patients with different degrees of splenomegaly (15-year OS: 100%, 78.6%, 71.7%, and 51.9%, respectively, P = 0.021). Conclusion The degree of splenomegaly, including volumetric splenomegaly, based on age- and BSA-matched reference spleen volumes at diagnosis reflects disease progression in PV patients. Therefore, volumetric splenomegaly should be evaluated at the time of diagnosis and taken into consideration when predicting the prognosis of patients with PV.

Real-world patient characteristics and treatment patterns of polycythemia vera in Taiwan between 2016 and 2017: a nationwide cross-sectional study

“… 26 A small study in South Korea that enrolled 125 PV patients reported that only 8% had palpable splenomegaly. 27 This study presented records of splenomegaly in 3.0% of low-risk patients and 3.8% in high-risk patients. Although the lack of routine sonography and motivation to record could be the reasons for the low percentage of splenomegaly in Taiwan, possible genetic factors resulting in differential phenotypes remain an intriguing topic for future study.…”

Abdominal aortic calcification in patients newly diagnosed with essential thrombocythemia

“…Abdominal CT is not routinely performed during the initial evaluation of ET patients [ 32 ]. The clinical relevance of volumetric splenomegaly and splenic infarction detected using abdominal CT performed at the time of diagnosis of Ph - MPN has been previously evaluated [ 23 , 33 , 34 ]. Furthermore, in a small proportion of patients, abdominal CT has been used to detected asymptomatic malignancies at the time of diagnosis of Ph - MPN.…”

Incidental abdominal computed tomography findings in patients newly diagnosed with Philadelphia-negative myeloproliferative neoplasm

“…As previously reported, abdominal CT detects volumetric splenomegaly in all pre-PMF patients and in only 50% of ET patients at diagnosis [ 7 ]. PV patients with volumetric splenomegaly at diagnosis had a poorer prognosis than those without; however, the prognosis is better than that of patients with palpable splenomegaly [ 8 ]. In addition, abdominal CT performed at the time of MPN diagnosis revealed asymptomatic splenic infarction [ 9 ] and abdominal aortic calcification, indicative of a poor prognosis (submitted for publication).…”

“…Despite these limitations, we found that a small population of Ph - MPN patients had asymptomatic splanchnic thrombosis and malignant tumors at the time of MPN diagnosis. As mentioned earlier, we previously reported that volumetric splenomegaly and asymptomatic splenic infarction detected by abdominal CT performed at the time of diagnosis are clinically useful for determining the diagnosis and prognosis [ 7 - 9 ]. The advantages of performing abdominal CT may offset the risks associated with radiation exposure and medical costs.…”