re: #159 William Lewis

Funky. Almost as good as the Army sniper friend of mine who had his spleen taken out, had his white blood count drop to an impossible 0 (as in NO white blood cells detectable in the lab) and then his spleen grew back (!). The docs are still shrugging about that.

Return of a normal functioning spleen after traumatic splenectomy (Journal of the Royal Society of Medicine via NIH)

Spleen can regenerate through various mechanisms. Autotransplantation of splenic tissue after traumatic disruption of the splenic capsule is well recognized.1 Splenic tissue can lodge anywhere in the peritoneal cavity following traumatic disruption and regenerates under favourable conditions.2 The incidence of splenic regeneration correlates with the severity of splenic injury:3 patients requiring a splenectomy for trauma tend to be those with greatest splenic damage and dissipation of splenic tissue, which favours autotransplantation. These splenic implants, called splenosis, can be found anywhere in the peritoneal cavity. They are supplied by newly formed arteries that penetrate the capsule.4

Accessory spleens, on the other hand, are common prevalence 10-31% in autopsy series.5 They result from incomplete fusion of separated fetal spleen tissue originating from the dorsal mesogastrium.6 In healthy individuals, accessory spleens usually measure only a few millimetres in diameter5 and may be undetectable on routine imaging. These accessory spleens can enlarge following splenectomy and be the source of recurrent symptoms in those operated on for blood disorders. An accessory spleen derives its blood supply from branches of the splenic artery.4

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TL;DR: Spleens can grow back.