Splenomegaly is an enlargement of thespleen.[1] The spleen usually lies in the left upper quadrant (LUQ) of thehuman abdomen. Splenomegaly is one of the four cardinal signs ofhypersplenism which include: some reduction in number of circulating blood cells affectinggranulocytes,erythrocytes orplatelets in any combination; a compensatory proliferative response in the bone marrow; and the potential for correction of these abnormalities bysplenectomy. Splenomegaly is usually associated with increased workload (such as inhemolytic anemias), which suggests that it is a response to hyperfunction. It is therefore not surprising that splenomegaly is associated with anydisease process that involves abnormalred blood cells being destroyed in the spleen. Other common causes include congestion due toportal hypertension and infiltration byleukemias andlymphomas. Thus, the finding of an enlarged spleen, along withcaput medusae, is an important sign of portal hypertension.[2]
For children, the cutoffs for splenomegaly are given in this table, when measuring the greatest length of the spleen between its dome and its tip, in thecoronal plane through its hilum while breathing quietly.[7]
Atautopsy, splenomegaly can be defined as a spleen weight above the upper limit of the standardreference range of 230 g (8.1 oz).[8][9]
Splenomegaly refers strictly to spleen enlargement, and is distinct from hypersplenism, which connotes overactive function by a spleen of any size. Splenomegaly and hypersplenism should not be confused. Each may be found separately, or they may coexist. Clinically, if a spleen is palpable (felt viaexternal examination), it means it is enlarged as it has to undergo at least twofold enlargement to become palpable. However, the tip of the spleen may be palpable in a newborn baby up to three months of age.[10]
Calculators have been developed for measurements of spleen size based onCT,US, andMRI findings.[11]
Symptoms may includeabdominal pain, chest pain, chest pain similar topleuritic pain when stomach, bladder or bowels are full, back pain, early satiety due to splenic encroachment, or the symptoms ofanemia due to accompanyingcytopenia.
Signs of splenomegaly may include a palpable left upper quadrantabdominal mass or splenic rub. It can be detected onphysical examination by usingCastell's sign,Traube's space percussion orNixon's sign, but anultrasound can be used to confirm diagnosis. In patients where the likelihood of splenomegaly is high, the physical exam is not sufficiently sensitive to detect it; abdominal imaging is indicated in such patients.[12]
In cases ofinfectious mononucleosis splenomegaly is a common symptom and health care providers may consider usingabdominal ultrasonography to get insight into a person's condition.[13] However, because spleen size varies greatly, ultrasonography is not a valid technique for assessing spleen enlargement and should not be used in typical circumstances or to make routine decisions about fitness for playing sports.[13]
If the splenomegaly underlies hypersplenism, asplenectomy is indicated and will correct the hypersplenism. However, the underlying cause of the hypersplenism will most likely remain; consequently, a thorough diagnostic workup is still indicated, as, leukemia, lymphoma and other serious disorders can cause hypersplenism and splenomegaly. After splenectomy, however, patients have an increased risk for infectious diseases.
An enlarged spleen may be an inherited, adaptive trait selected in populations that need extra oxygen carry capacity such as deep sea divers.[22][23] TheSama-Bajau people, notable for free-diving, have spleens that are 50% larger than those of nearby ethnic groups.[24][23]
^Chow, Kai Uwe; Luxembourg, Beate; Seifried, Erhard; Bonig, Halvard (2016). "Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals".Radiology.279 (1):306–313.doi:10.1148/radiol.2015150887.ISSN0033-8419.PMID26509293.
^abRosenberg, H K; Markowitz, R I; Kolberg, H; Park, C; Hubbard, A; Bellah, R D (1991). "Normal splenic size in infants and children: sonographic measurements".American Journal of Roentgenology.157 (1):119–121.doi:10.2214/ajr.157.1.2048509.ISSN0361-803X.PMID2048509.
Putukian, M; O'Connor, FG; Stricker, P; McGrew, C; Hosey, RG; Gordon, SM; Kinderknecht, J; Kriss, V; Landry, G (Jul 2008). "Mononucleosis and athletic participation: an evidence-based subject review".Clinical Journal of Sport Medicine.18 (4):309–15.doi:10.1097/jsm.0b013e31817e34f8.PMID18614881.S2CID23780443.
Spielmann, AL; DeLong, DM; Kliewer, MA (Jan 2005). "Sonographic evaluation of spleen size in tall healthy athletes".AJR. American Journal of Roentgenology.184 (1):45–9.doi:10.2214/ajr.184.1.01840045.PMID15615949.
^Kaiser, Larry R.; Pavan Atluri; Giorgos C Karakousis; Paige M Porrett (2006).The surgical review: an integrated basic and clinical science study guide. Hagerstwon, MD: Lippincott Williams & Wilkins.ISBN0-7817-5641-3.
^Durden LA (1995). "Bot Fly (Cuterebra fontinella fontinella) Parasitism of Cotton Mice (Peromyscus gossypinus) on St. Catherines Island, Georgia".The Journal of Parasitology.81 (5):787–790.doi:10.2307/3283977.JSTOR3283977.PMID7472877.
^Friedman, AD.; Daniel, GK.; Qureshi, WA. (Jun 1997). "Systemic ehrlichiosis presenting as progressive hepatosplenomegaly".South Med J.90 (6):656–60.doi:10.1097/00007611-199706000-00017.PMID9191748.
^Neufeld EF, Muenzer J (1995). "The mucopolysaccharidoses". In Scriver CR, Beaudet AL, Sly WS, Valle D (eds.).The metabolic and molecular bases of inherited disease.7th ed. Vol. 2. McGraw-Hill, New York. pp. 2465–94.
^Suvajdzić, N.; Cemerikić-Martinović, V.; Saranović, D.; Petrović, M.; Popović, M.; Artiko, V.; Cupić, M.; Elezović, I. (Oct 2006). "Littoral-cell angioma as a rare cause of splenomegaly".Clinical and Laboratory Haematology.28 (5):317–20.doi:10.1111/j.1365-2257.2006.00801.x.PMID16999722.
^Ziske, C.; Meybehm, M.; Sauerbruch, T.; Schmidt-Wolf, IG. (Jan 2001). "Littoral cell angioma as a rare cause of splenomegaly".Ann Hematol.80 (1):45–8.doi:10.1007/s002770000223.PMID11233776.S2CID29326931.
^abIlardo, M. A.; Moltke, I.; Korneliussen, T. S.; Cheng, J.; Stern, A. J.; Racimo, F.; de Barros Damgaard, P.; Sikora, M.; Seguin-Orlando, A.; Rasmussen, S.; van den Munckhof, I. C. L.; ter Horst, R.; Joosten, L. A. B.; Netea, M. G.; Salingkat, S.; Nielsen, R.; Willerslev, E. (2018-04-18)."Physiological and Genetic Adaptations to Diving in Sea Nomads".Cell.173 (3): 569–580.e15.doi:10.1016/j.cell.2018.03.054.PMID29677510.
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