Splenomegaly
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Background
There are many causes of splenomegaly and the exam for splenomegaly is relatively straightforward. But it turns out the exam for splenomegaly is not very accurate or reproducible (see Table 1 below). The spleen is normally small and very much ‘protected’ by ribs such that it should not be palpable in a normal person, even with deep inspiration or palpation (in contrast to the liver, for example). Therefore, it must become quite large to be detected. Additionally, though the neighboring stomach and bowels are air filled, useful to differentiate solid spleen from air, they vary widely in size and distention, even in a single patient from moment to moment. These are likely why the exam maneuvers struggle. Regardless we review them here.
Traube Space
Learning about Traube Space probably is most useful for roundsmanship. It’s true clinical utility may be limited given poor operating characteristics and reproducibility (+LR 2.1, -LR 0.8, kappa 0.19-0.41) [1]. Traube space is the space over the stomach air bubble. Anatomically it is surrounded by the left lobe of the liver, the spleen and the lower heart border.
Externally it is defined superiorly by a line between the costochondral junction at the 6th rib to the 9th rib at the anterior axillary line. This line is extended inferiorly to the costal margin. If this space is dull to percussion, the sign is positive.
Percussion
Percussion for splenic enlargement has been descried in two ways. One involves percussion moving medially to laterally (around the level of Traube space). If dullness is encountered anterior to the mid axillary line, the finding is positive.
Alternatively, if one percusses lateral from Traube space (between mid and anterior axillary lines) and notes alternating dullness with inspiration and expiration, the finding is positive.
Percussion has not been shown reliable and is moderately reproducible (LR+ 1.7, LR- 0.7, kappa 0.38-0.85) [1].
Palpation
There are multiple techniques. Most stress starting sufficiently far from the LUQ to avoid missing splenic enlargement. Additionally, firm, even, and steady pressure can limit pain and decrease abdominal muscle flexion, improving results. Palpation is not sensitive (LR- 0.5) but is specific for Splenomegaly (LR+ 8.5). Reproducibility is weak to modest, however (kappa 0.33-0.75) [1].
POCUS for Splenomegaly
The examiners were allowed to examine for splenic enlargement “according to the examiners’ usual clinical practice”. This exam on 39 patients had a LR+ of 3.4 (95 % CI 0.83–14) and a LR- of 0.68 (95 % CI 0.33–1.41) for Splenomegaly.
When POCUS was added, the LR+ did not improve much (3.8, 95 % CI 2.16–6.62) but the LR- was 0. It should be noted not many of the 39 patients had splenomegaly. Here is a quick primer on performing POCUS for splenomegaly.
Clincal practice Summary
In summary, POCUS is useful for ruling out Splenomegaly (LR- o) but the reproducibility has not been described. Most POCUS applications are extremely operator dependent and related to experience. Palpation is likely the most useful for ruling in Splenomegaly (LR+ 8.5), though its reproducibility is modest (kappa 0.33-0.75). Traube space or other percussion for Splenomegaly are not reliable and weakly or modestly reproducible.
Table 1
| Clinical finding | Sensitivity (%) | Specificity (%) | +LR | -LR | κ–statistic |
| Palpation | 18-78 | 89-99 | 8.5 | 0.5 | 0.33-0.75 |
| Spleen percussion sign | 25-85 | 32-94 | 1.7 | 0.7 | 0.38-0.85 |
| Traube space dullness | 11-76 | 63-95 | 2.1 | 0.8 | 0.19-0.41 |
