Accessory Spleens in Idiopathic Thrombocytopenic Purpura
The correct answer is (a) idiopathic thrombocytopenic purpura (ITP), as accessory spleens are clinically most relevant in this condition where they can cause treatment failure after splenectomy.
Clinical Significance in ITP
Accessory splenic tissue is found in up to 12% of splenectomized ITP patients, and assessment for accessory spleens should be considered in patients who relapse following an initial response to splenectomy 1. This represents the highest clinical relevance among the listed conditions because:
- Approximately 20% of ITP patients who initially respond to splenectomy will relapse weeks, months, or years later 1
- In patients who relapse after initial splenectomy response, the presence of accessory splenic tissue may explain the recurrence of thrombocytopenia 1
- Imaging techniques can identify these accessory spleens, and almost all can be removed during surgery 1
Why ITP Over Other Conditions
Hereditary Spherocytosis Context
While accessory spleens are also clinically important in hereditary spherocytosis, the evidence shows:
- Accessory spleens must be sought and removed at the time of splenectomy in hereditary spherocytosis patients 2
- Recurrent hemolytic anemia can occur due to hypertrophied accessory spleens in hereditary spherocytosis 3
- However, the question asks where accessory spleens are "most commonly found," and the ITP guidelines specifically quantify this at 12% of splenectomized patients 1
Other Conditions
- Thrombotic thrombocytopenic purpura (TTP): Splenectomy is not a standard treatment for TTP, making accessory spleens clinically irrelevant in this condition 4
- Schistosomiasis: No evidence provided links accessory spleens to this parasitic infection
Critical Clinical Pitfall
In patients who never responded to initial splenectomy, searching for accessory spleens is futile as response is extremely rare 1. This distinguishes between:
- Relapsers after initial response → assess for accessory spleen
- Non-responders from the start → accessory spleen unlikely to be the cause