splenomegaly

Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is one of the four cardinal signs of hypersplenism which include: some reduction in number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any combination; a compensatory proliferative response in the bone marrow; and the potential for correction of these abnormalities by splenectomy. Splenomegaly is usually associated with increased workload (such as in hemolytic anemias), which suggests that it is a response to hyperfunction. It is therefore not surprising that splenomegaly is associated with any disease process that involves abnormal red blood cells being destroyed in the spleen. Other common causes include congestion due to portal hypertension and infiltration by leukemias and lymphomas. Thus, the finding of an enlarged spleen, along with caput medusae, is an important sign of portal hypertension.

==Definition== thumb|150px|Maximum dimension of the spleen on abdominal ultrasonography. The standard system for classifying splenomegaly on radiography is: Normal (not splenomegaly): the largest dimension is less than 11 cm Moderate splenomegaly: the largest dimension is between 11 and 20 cm Severe splenomegaly: the largest dimension is greater than 20 cm Also, a cutoff of a craniocaudal height of 13 cm is also used to define splenomegaly. In addition, individual intervals have been established: {|class="wikitable" align="center" |+ 90% confidence interval of maximum spleen length by abdominal ultrasonography by height of the person |- !rowspan=2| Height !!colspan=2| Spleen length |- ! Women !! Men |- | 155 – 159 cm || 6.4 – 12 cm || |- | 160 – 164 cm || 7.4 - 12.2 cm || 8.9 - 11.3 cm |- | 165 – 169 cm || 7.5 – 11.9 cm || 8.5 – 12.5 cm |- | 170 – 174 cm || 8.3 – 13.0 cm || 8.6 – 13.1 cm |- | 175 – 179 cm || 8.1 – 12.3 cm || 8.6 – 13.4 cm |- | 180 – 184 cm || || 9.3 – 13.4 cm |- | 185 – 189 cm || || 9.3 – 13.6 cm |- | 190 – 194 cm || || 9.7 – 14.3 cm |- | 195 – 199 cm || || 10.2 – 14.4 cm |}