Splenic Cyst: Causes, Types, Symptoms, Treatment, Complications, Diagnosis

Splenic cyst is a rare condition, in which a cyst or a fluid filled sac may be formed in the spleen. Splenic cyst can appear as a focal lesion on the radiograph of spleen. It may not produce any symptoms in most cases, but some people with splenic cyst may experience pain and swelling around the spleen region.

Splenic cyst may not be easily detected as it may not always show symptoms, however, some cases may be detected during an imaging study for some other purpose. Splenic cyst, although not very common, is an important condition that needs to be evaluated, diagnosed and treated appropriately to avoid further problems.

The spleen is an important organ, situated on the left upper side of the abdomen, close to the stomach. Normally, the spleen cannot be felt on palpation, it can be felt or palpated only when it is enlarged. One of the conditions that can cause enlargement of spleen can be splenic cyst and other causes affecting the spleen.

Spleen is a vascular structure and is an important part of the immune system of the body. Spleen is responsible for producing white blood cells, which are the fighter cells of the body, which help to fight infections. Spleen produces cells and performs the function of phagocytosis or removal of old cells, debris and filters blood. It also stores red blood cells.

As the spleen perform important functions, particularly of filtering blood and removing impurities from it, the spleen is constantly exposed to toxic substances. Such harmful substances can cause some damage to the spleen. In rare cases, splenic cysts may be formed due to various causes affecting the spleen.

Splenic cysts usually do not present with any symptoms unless some exacerbation occurs to the existing condition. Most of the cases of splenic cysts may be identified incidentally or due to some symptoms.

Symptoms of splenic cyst, when present, often include dull, aching pain in stomach, more in upper left region of the abdomen. Other general gastric disturbances may be present in some cases. There may be a feeling of fullness in the abdomen, early satiety, nausea and sometimes vomiting after eating food.

Tenderness in the area of spleen or the upper left abdominal region and palpable spleen due to swelling of spleen or splenomegaly may be noted on examination in most cases, even if they remain asymptomatic.

Splenic cyst can be a cyst on the spleen or sometimes may appear as cystic lesions on the spleen due to certain conditions affecting the spleen. Splenic cysts can be a result of various conditions and hence splenic cysts can be abscesses, benign cysts or neoplastic cysts. Splenic cysts are mainly identified on radiological studies and hence are noted on various types of scans. The cystic lesions on spleen appear similar and is difficult to differentiate by seeing the images. Only further study of the splenic cyst can help to identify the exact nature of the cystic lesion on spleen.

The Common Causes Of Cystic Lesions On Spleen Include:

• Cause of Congenital Splenic Cyst – These splenic cysts are true cysts and are caused due to defects in developmental origin.
• Cause of Inflammatory Splenic Cyst – These splenic cysts may be caused due to abscess and hydatid cysts.
• Cause of Vascular Splenic Cyst – Vascular splenic cysts often result from peliosis and infarction.
• Causes of Post-Traumatic Splenic Cyst – Splenic cysts can occur due to trauma to the splenic region resulting in hematoma and false cysts.
• Causes of Neoplastic Splenic Cyst – These cystic lesions are caused by hemangioma, lymphangioma, lymphoma and metastatic lesions.

Splenic cyst can appear in different forms and are hence categorized into certain types. Here we can understand the various types of splenic cysts depending on the cause. The main differentiation of the splenic cysts include in that some splenic cysts may have a covering or a cellular lining and some splenic cysts may not have the covering. The most commonly considered types include primary splenic cysts and secondary splenic cysts, depending on the cause.

Primary splenic cysts, also called true or real cysts – These splenic cysts have a cellular lining or covering around them. These may be originated from parasitic or even non-parasitic causes.

• Parasitic True Splenic Cyst

These cysts on spleen are formed due to the presence of a parasitic organism in the body and more particularly in the spleen.

• Non-Parasitic True Splenic Cyst

Non-parasitic true splenic cyst may be congenital cysts in most cases, particularly epidermoid splenic cyst and sometimes dermoid splenic cyst.

The congenital or epithelial splenic cysts are quite common and are usually seen in children and young adults. The splenic cysts are usually solitary or single. These may usually be asymptomatic, however, sometimes congenital splenic cysts may also become symptomatic in certain cases. Trauma to the area can cause swelling resulting in increase in the size of the cyst, hemorrhage or other causes can lead to certain symptoms. In contrast to parasitic cysts, these cysts have smooth walls and wall calcification is commonly not seen but some septations may be seen.

The dermoid splenic cysts are very rare and many such cysts also have well differentiated tissues. Non-parasitic splenic cysts can be originated from congenital or epithelial, vascular, or neoplastic/malignant causes. These splenic cysts may originate during embryonic development or a genetic defect may be a cause of congenital true splenic cysts.

Secondary splenic cyst, also called false or pseudocyst – These splenic cysts do not have a cellular lining, capsule or covering around them. These types of splenic cysts are often a result of injury or trauma to the spleen or nearby surrounding structures in an abdominal trauma. Secondary splenic cyst can also result from splenic infarcts, infections or in combination with pancreatic pseudocysts, mostly after acute pancreatitis. Splenic cyst of this type can even occur due to pyogenic splenic abscess.

The common types and causes of splenic cysts are discussed in detail below.

1. Parasitic Splenic Cysts

   Parasitic splenic cysts may occur due to parasitic infections in the body. Splenic cyst can also result from hydatid cysts in the body, which are parasites of tapeworm. It is the most common parasitic infection, caused due to an organism called Echinococcus granulosus, while rare infections from its other variants are possible. These usually involve the liver or the lungs but can sometimes involve the spleen. Parasitic splenic cysts may be suspected if there are wall calcifications in the splenic cyst. Parasitic infections from other areas too can spread to the spleen spontaneously or after surgical procedures involving hydatidosis and similar parasitic complications.

2. Vascular Splenic Cysts

   Vascular splenic cysts can be peliosis or infarction.

   • Peliosis – Peliosis is an example of these type of vascular splenic cysts, however, it is a very rare disease. These are actually blood filled cysts and may be seen in the liver, but rarely also in the spleen. However, these lesions can be present in any organ and hence once detected, their presence in other organs must also be investigated. Peliosis may be a result of various toxins, long term alcoholism, long standing medications like steroids, oral contraceptives and others. Certain medical conditions like malignancies, multiple myeloma, and opportunistic infections in HIV-positive patients may be associated with the cause of vascular splenic cysts.

   These splenic cysts remain asymptomatic and may be detected during imaging studies or during surgeries, but appropriate treatment must be considered to avoid complications from spontaneous rupture of the spleen. Any ongoing medications need to be carefully planned to avoid bleeding and rupture. Such persons may be advised to avoid contact sports, adventure and high-risk activities; it is important to follow medical advice. Although there may not be a need to initiate treatment in incidental finding of such splenic cysts without symptoms; in case of spontaneous rupture of the spleen, immediate splenectomy may have to be performed.

   • Infarction – Infarction results from death of healthy cells mostly due to blood flow obstruction. It may be associated with other conditions like valvular heart disease, pancreatic carcinoma, lupus or in persons involved in intravenous substance abuse. Clinical features may include swelling of the spleen and pain in left upper part of the abdomen, particularly more during deep inspiration.

3. Splenic Abscess

   Splenic cysts can be caused due to pyogenic abscess, resulting in splenic abscess. The abscess often spreads via blood stream in most cases, while sometimes it can also spread due to injury to infected tissues and previous splenic infarction. Owing to the infective nature, presenting symptoms may include fever and chills in addition to pain in upper left abdominal region along with tenderness on examination.

4. Cystic Neoplasms

   Splenic cysts of neoplastic origin may include angiomas, lymphoma and metastases. Angiomas are congenital in origin. Splenic cyst with hemangioma is composed of blood vessel and lymphangioma is composed of lymph vessel. Lymphoma are rare types of splenic cysts. Metastases results from spread of a primary tumor from other areas like the breasts, ovary, endometrium, prostate, lungs or colon to form splenic cysts of neoplastic origin.

Splenic cysts, whether symptomatic or not, can be suspected with palpable spleen on examination. Other causes of splenomegaly may be ruled out based on history and clinical examination. Based on this, appropriate investigations may be ordered. Blood tests may be done to find infection, inflammation and specific tests for parasitic or other infections may be done.

Splenomegaly may be confirmed and studied in ultrasonography. Diagnosis of splenic cysts may be done with imaging studies of the abdomen, particular studies to note the spleen. However, most splenic cysts may appear similar on imaging studies. CT scan often shows splenic cysts with greater details, which aids in diagnosing. It may show parasitic splenic cyst as a solitary cyst, which may sometimes show wall calcifications. An MRI scan may also be done, if found necessary. In some cases, angiography may be performed to differentiate a vascular splenic cyst from a solid cystic lesion, particularly in cysts with malignant origin.

Asymptomatic and uncomplicated cases of splenic cysts may not require any treatment. Treatment of splenic cysts include surgical removal of spleen or splenectomy, if appropriate. This surgical procedure is performed when the size of the cyst on spleen is large or when there is a risk of spread of infection. Splenectomy in such cases, can help to control further infection and prevent potential complications.

The choice of surgical procedure often depends on the location of the splenic cyst. If the splenic cyst is located on the front or the anterior side, laparoscopic procedure can be considered. For the cyst on the rear or the posterior side, laparoscopic surgery may be difficult. While for a splenic cyst, which is located centrally, laparoscopic may not be advisable and an open partial surgery may be considered. The decision of treatment and its options needs to be taken wisely and it is important to follow medical advice correctly.

Splenic cysts do not usually cause complications, however, in some cases, complications like infection, bleeding and splenic rupture can occur. This may need immediate medical attention.