Splenosis

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Splenosis is the result of spleen tissue breaking off the main organ and implanting at another site inside the body. This is called heterotopic autotransplantation of the spleen. It most commonly occurs as a result of traumatic splenic rupture or abdominal surgery. Depending on the location of the spleen, the new piece usually implants in another part of the abdominal cavity (including the pelvic cavity). Single case reports also describe splenosis in the thoracic cavity, in subcutaneous tissue, in the liver or in the cranial cavity. Splenosis must be distinguished from the presence of additional spleens, which are innate and are the result of differences in embryological development. Additionally, splenosis must be differentiated from malignant tumors which may look similar when imaged. [1]

Contents

History

Ectopic splenic tissue was first described in 1896 by Albrecht in Germany, whereas the term “splenosis” was first used by Buchbinder and Lipkoffin to describe their findings in 1939 [2]

Cause

A necessary requirement for splenosis is the rupture of the spleen, through a traumatic injury (such as a car wreck) or abdominal surgery, especially splenectomy. Splenosis in the abdominal category may occur in up to 65% of traumatic ruptures of the spleen. [3] Splenosis in the thoracic cavity is rarer, because it requires the simultaneous rupture of the diaphragm. The implantation of spleen tissue under the skin may result from abdominal surgery or gunshot wounds. Splenosis of the brain or liver is hypothesized to be the result of tiny pieces of spleen tissue traveling through the bloodstream.

Pathology

Several implants of splenic tissue have implanted in the soft tissue of the left upper abdomen. The person had experienced splenic rupture during a car wreck and subsequent surgical removal of the spleen four years before this photo was taken. Splenose.jpg
Several implants of splenic tissue have implanted in the soft tissue of the left upper abdomen. The person had experienced splenic rupture during a car wreck and subsequent surgical removal of the spleen four years before this photo was taken.

Macroscopically, splenosis manifests as individual pieces of reddish-blue tissue with variable shape, which can be as few as one and as many as 300, [4] mostly in the abdominal cavity, and varying in size from a few millimeters to as large as 12 cm. Due to the limited blood supply to these nodules, the typical size of splenic implants is usually less than 3 cm. The implants can be separate pieces or connect to other pieces of splenic tissue by a thin stem. [5] Histologically, the regular spleen tissue is made up of red and white pulp, similar to the structure of an accessory spleen.

Clinical presentation

About a decade commonly passes between the injury and the discovery of splenosis. As little as five months and as much as 32 years have been reported. Most people with splenosis have no symptoms, so the splenosis is discovered by chance through screening or in the process of diagnosing another disease. Some people experience symptoms, such as abdominal pain, intestinal obstruction, hemorrhage, or hydronephrosis. Tissue infarction due to limited blood supply can be a cause of symptomatic splenosis. [6] Symptoms of splenosis affecting the thoracic cavity sometimes include hemoptysis or pleurisy.

Diagnosis

A definitive diagnosis is often made through biopsy and histological examination of the tissue by a pathologist. Multiple implants of splenic tissue can mimic the appearance of some cancerous conditions. This can be clarified through diagnostic imaging (for example, ultrasound, CT scan, and MRI).

In particular, splenosis is differentiated from different forms of lymphoma, metastisized cancers, cancer of the abdomen and pleural tissues, primary kidney or liver tumors, endometriosis or non-cancerous swollen lymph nodes.

Treatment

Treatment of splenosis is often unnecessary, because it is benign and usually asymptomatic. For people experiencing symptoms, the splenic tissue can be removed by surgery.

Epidemiology

Splenosis is slightly more common in males than females, probably due to the greater frequency of physical trauma experienced by men. [7]

Related Research Articles

Spleen Internal organ in most vertebrates

The spleen is an organ found in all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes from Ancient Greek σπλήν (splḗn).

Splenectomy Surgical removal of the spleen

A splenectomy is the surgical procedure that partially or completely removes the spleen. The spleen is an important organ in regard to immunological function due to its ability to efficiently destroy encapsulated bacteria. Therefore removal of the spleen runs the risk of overwhelming post-splenectomy infection, a medical emergency and rapidly fatal disease caused by the inability of the body's immune system to properly fight infection following splenectomy or asplenia.

Abdominal pain Stomach aches

Abdominal pain, also known as a stomach ache, is a symptom associated with both non-serious and serious medical issues.

Volvulus Twisting of part of the intestine, causing a bowel obstruction

A volvulus is when a loop of intestine twists around itself and the mesentery that supports it, resulting in a bowel obstruction. Symptoms include abdominal pain, abdominal bloating, vomiting, constipation, and bloody stool. Onset of symptoms may be rapid or more gradual. The mesentery may become so tightly twisted that blood flow to part of the intestine is cut off, resulting in ischemic bowel. In this situation there may be fever or significant pain when the abdomen is touched.

Hemothorax Blood accumulation in the pleural cavity

A hemothorax is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may include reduced breath sounds on the affected side and a rapid heart rate. Hemothoraces are usually caused by an injury, but they may occur spontaneously due to cancer invading the pleural cavity, as a result of a blood clotting disorder, as an unusual manifestation of endometriosis, in response to a collapsed lung, or rarely in association with other conditions.

Abdominal pregnancy Medical condition

An abdominal pregnancy can be regarded as a form of life threatening condition ectopic pregnancy where the embryo or fetus is growing and developing outside the womb in the abdomen, but not in the Fallopian tube, ovary or broad ligament.

Splenic injury Medical condition

A splenic injury, which includes a ruptured spleen, is any injury to the spleen. The rupture of a normal spleen can be caused by trauma, such as a traffic collision.

Blunt trauma Physical trauma caused to a body part, either by impact, injury or physical attack

Blunt trauma, also known as blunt force trauma or non-penetrating trauma, is physical trauma or impactful force to a body part, often occurring with road traffic collisions, direct blows, assaults, injuries during sports, and particularly in the elderly who fall. It is contrasted with penetrating trauma which occurs when an object pierces the skin and enters a tissue of the body, creating an open wound and bruise.

Greater omentum Fat sheath under abdominal wall

The greater omentum is a large apron-like fold of visceral peritoneum that hangs down from the stomach. It extends from the greater curvature of the stomach, passing in front of the small intestines and doubles back to ascend to the transverse colon before reaching to the posterior abdominal wall. The greater omentum is larger than the lesser omentum, which hangs down from the liver to the lesser curvature. The common anatomical term "epiploic" derives from "epiploon", from the Greek epipleein, meaning to float or sail on, since the greater omentum appears to float on the surface of the intestines. It is the first structure observed when the abdominal cavity is opened anteriorly.

Splenic infarction Medical condition

Splenic infarction is a condition in which blood flow supply to the spleen is compromised, leading to partial or complete infarction in the organ. Splenic infarction occurs when the splenic artery or one of its branches are occluded, for example by a blood clot.

Hemoperitoneum is the presence of blood in the peritoneal cavity. The blood accumulates in the space between the inner lining of the abdominal wall and the internal abdominal organs. Hemoperitoneum is generally classified as a surgical emergency; in most cases, urgent laparotomy is needed to identify and control the source of the bleeding. In selected cases, careful observation may be permissible. The abdominal cavity is highly distensible and may easily hold greater than five liters of blood, or more than the entire circulating blood volume for an average-sized individual. Therefore, large-scale or rapid blood loss into the abdomen will reliably induce hemorrhagic shock and, if untreated, may rapidly lead to death.

Spleen transplantation is the transfer of spleen or its fragments from one individual to another. It is under research for induction of immunological tolerance for other transplanted organs. Success has been achieved in rodent models. Recently, evidence has been obtained for a tolerogenic effect of a spleen transplant in miniature swine. Also, the spleen harbors primitive hematopoietic progenitor cells. Spleen transplantation has been performed on humans with mixed results.

Phrenicocolic ligament

A fold of peritoneum, the phrenicocolic ligament is continued from the left colic flexure to the thoracic diaphragm opposite the tenth and eleventh ribs; it passes below and serves to support the spleen, and therefore has received the name of sustentaculum lienis.

Accessory spleen Small nodule found apart from the main body of the spleen

An accessory spleen is a small nodule of splenic tissue found apart from the main body of the spleen. Accessory spleens are found in approximately 10 percent of the population and are typically around 1 centimetre in diameter. They may resemble a lymph node or a small spleen. They form either by the result of developmental anomalies or trauma. They are medically significant in that they may result in interpretation errors in diagnostic imaging or continued symptoms after therapeutic splenectomy. Polysplenia is the presence of multiple accessory spleens rather than one normal spleen.

Penetrating trauma Type of injury

Penetrating trauma is an injury that occurs when an object pierces the skin and enters a tissue of the body, creating an open wound. The penetrating object may remain in the tissues, come back out the way it entered, or pass through the tissues and exit from another area. An injury in which an object enters the body or a structure and passes all the way through is called a perforating injury, while penetrating trauma implies that the object does not pass through. Perforating trauma is associated with an entrance wound and an often larger exit wound.

Abdominal trauma Medical condition

Abdominal trauma is an injury to the abdomen. Signs and symptoms include abdominal pain, tenderness, rigidity, and bruising of the external abdomen. Complications may include blood loss and infection.

Diaphragmatic rupture Tear in the thoracic diaphragm, usually caused by physical trauma

Diaphragmatic rupture is a tear of the diaphragm, the muscle across the bottom of the ribcage that plays a crucial role in breathing. Most commonly, acquired diaphragmatic tears result from physical trauma. Diaphragmatic rupture can result from blunt or penetrating trauma and occurs in about 0.5% of all people with trauma.

Tumor-like disorders of the lung pleura are a group of conditions that on initial radiological studies might be confused with malignant lesions. Radiologists must be aware of these conditions in order to avoid misdiagnosing patients. Examples of such lesions are: pleural plaques, thoracic splenosis, catamenial pneumothorax, pleural pseudotumor, diffuse pleural thickening, diffuse pulmonary lymphangiomatosis and Erdheim–Chester disease.

Canine gallbladder mucocele (GBM) is an emerging biliary disease in dogs described as the excessive and abnormal accumulation of thick, gelatinous mucus in the lumen, which results in an enlarged gallbladder. GBMs have been diagnosed more frequently in comparison to prior to the 2000s when it was considered rare. The mucus is usually pale yellow to dark green in appearance.

Spleen pain

Spleen pain is a pain felt from the left upper quadrant of the abdomen or epigastrium where the human spleen is located or neighboring.

References

  1. R. D. Fremont, T. W. Rice: Splenosis: A Review.
  2. Younan, George; Wills, Edward; Hafner, Gordon (2015). "Splenosis: A Rare Etiology for Bowel Obstruction—A Case Report and Review of the Literature". Case Reports in Surgery. 2015: 890602. doi: 10.1155/2015/890602 . ISSN   2090-6900. PMC   4620401 . PMID   26543660.
  3. A. H. Huang, K. Shaffer: Case 93: thoracic splenosis.
  4. Widmann, MAJ Warren D. (1971-02-01). "Splenosis: A Disease or a Beneficial Condition?". Archives of Surgery. 102 (2): 152–8. doi:10.1001/archsurg.1971.01350020062018. ISSN   0004-0010. PMID   5101334.
  5. C. R. Fleming, E. R. Dickson, E. G. Harrison, Jr: Splenosis: auto-transplantation of splenic tissue.
  6. Widmann, MAJ Warren D. (1971-02-01). "Splenosis: A Disease or a Beneficial Condition?". Archives of Surgery. 102 (2): 152–8. doi:10.1001/archsurg.1971.01350020062018. ISSN   0004-0010. PMID   5101334.
  7. J. N. Yammine, A. Yatim, A. Barbari: Radionuclide imaging in thoracic splenosis and a review of the literature.