Introduction
Auto transplantation of splenic tissue, which is usually caused by traumatic rupture of the spleen, is called splenosis. Heterogeneous splenic nodules were first described by Koterner woon in 1910. In a patient`s autopsy, he found the spleen tissue implantation in the peritoneal cavity [1]. However, the term splenosis was first used by Buchbinder and Lipkoff in 1939 [2]. In the present study, a woman with chronic abdominal pain, severe menstrual pain, ultrasonography of endometrioma cyst in the right ovary and posterior cul-de-sac has been introduced, who ultimately was diagnosed with splenosis.
Patient and methods
A 36-year-old woman, G2P1Ab1, with a 17-year secondary infertility complaint, chronic pelvic pain and dysmenorrhea, referred to an infertility clinic, and was admitted with a diagnosis of endometriosis for laparoscopy. With similar complaint, she was under laparoscopy in Mashhad 11 years ago, and her surgery was natural. The patient then had 4 failed IUI records until 2010. Prior to this, she also had a history of cesarean, hypothyroidism, and galactorrhea. However, she had no drug use at all, and all her tests were normal. In the pelvic exam, the uterus was of the natural anthrax but painful at the touch. The right ovary was large and painful, but the left ovary and the cul-de-sac were normal.
In vaginal ultrasonography, there were a normal sized uterus, a cystic lesion with elevated septum and echogenic particles in the right ovary with a size of 27X 33m, and two similar lesions in the posterior cul-de-sac with dimensions of 17 x 28 and 12x 25 mm with initial report and diagnosis of endometriosis or endometrium cyst. The patient diagnosed with probable endometrium and secondary 17-year infertility under laparoscopy. In laparoscopy, there were a severe adhesion of the omentum to the abdominal wall and severe adhesion of the ovaries to cul-de-sac. There was also an endometrioma cyst with a size of 3x2 cm in the right ovary which was cauterized and the cyst wall was sent for pathology (Fig. 1). The biopsy sample was taken from reddish bumps of less than one cm on the left ovary and was sent for pathology, and the patient`s fallopian tubes were open. All of the suspected cases of endometriosis on the ovaries and pelvic cavity were cauterized, and the rest of the pelvic cavity was normal. The pathologic study revealed the presence of splenic tissue in lesions, which included fibrous connective tissue with large area of red and white spleen, with areas of hemosiderin pigmentation and extra-medullary hemorrhages, and was placed in the ultimate diagnosis of pelvic splenosis. In keeping track of the patient`s history, she remembered the history of splenectomy at the age of four due to rupture caused by accident. The patient had no problem after the surgery, and the patient`s pain improved until four months after surgery.
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Figure 1) Different views of pelvic splenosis
Discussion
Road accidents with impact on the abdomen and tis complications are one the most common medical problems in the community, and less than 100 cases of splenosis have been reported in many sources, which are far lower in women in the primary sources [3-9]. Splenosis usually occurs after the impact on the spleen and the following splenectomy. The spleen remains are easily implanted on the surface of the serozal layer and the parasites adjacent blood vessels and grows to the adult spleen tissue. Implantation of damaged pulp is the main mechanism of auto-transplantation after spleen rupture. Other mechanisms are the hematopoietic release of the spleen tissue or the anterior cells of the red blood cells in the spleen and their subsequent growth in response to tissue hypoxia [10]. Splenosis is usually found in the upper left abdominal lobe [11]. Auto-transplantation of the spleen tissue in all areas of sputum has been described by Skinner and Stovall [6, 12]. Splenosis has been reported in thoracic, subcutaneous [13-16], and brain [17]. Three cases of ovarian splenosis has also been reported [18]. The actual incidence of splenosis is unclear. However, in a study done by Muller and Rothlin in 1995, the patients were undergone ultrasonography following splenectomy caused by impact and the results showed that splenosis is likely to occur in one third of the patients. However, this was not confirmed in the histology of the patients [19]. Usually, implantations have the diameter of 3 to 4 cm, and they appear with a capsule or a weak capsule. They have a mess structure; they do not have a naval, and are fed by the local arteries that are filled by fibrotic capsules. They are one and more and are reddish-blue. Histologically, they are distinctly comprised of spleen tissue. They have a natural spleen function, and they are histologically and immunohistochemically indistinguishable from the spleen. However, they are distinguishable from the sub-spleen with the location history and microscopy investigation [16, 20, and 21].
This disease usually occurs in adolescence. The average time between splenectomy and splenosis is 10 years (5 months to 36 years) which was 30 years in our patient [22]. Splenosis is usually asymptomatic, and spleen implantation is randomly found during the diagnostic imaging or surgery, not associated with splenosis. Occasionally, abdominal splenosis may be manifested with gastrointestinal bleeding [23, 24], or may cause abdominal pain and intestine obstruction, peritoneal nodules necrosis, hematoma, pelvic or abdominal mass and urethral enlargement. Hydronephrosis induced by pressure [25-28] or recurrence of the diseases is treated by the removal of the spleen [29]. Possible diagnosis can be carried out with the history of the patient`s removal of the spleen, or the least abdominal impact, the absence of reticulocytosis, Howell-Jolly body in the peripheral blood smear of the patient, or the history of the removal of the spleen that is often observed after the removal of spleen and the marked increase in the serum level of antipneumococcal antibodies in the unvaccinated patient or tracing with a heat-injured TCB-induced RBC trait with heat [30, 31].
Splenosis may imply endometriosis. Endometriosis has occurred initially in splenosis and other cases [9]. The difference between the two may be the difference between peritoneal release and lack of adhesion in splenosis. Sub-spleen is common finding in autopsy and its prevalence is 10%, usually isolated and is liquefied by a branch of a splenic artery [32]. The cause of this is the multi-focal evolution of the spleen and its break in the joints of one or more focal points. The most common site is the spleen naval, and has been found with lower incidence in the tail of pancreas, the liver and the posterior of peritoneum. Splenic-gonadal joining is due to the connection of the spleen and gonadal organs during fetal development, most of which has been reported in males, which may be due to the difference in the incidence in males and females, or may be due to the more availability of gonads in men [33]. In addition, except in one case, this splenic-gonadal joining involves left gonad [34].
Splenic-gonadal joining is in two forms; the first form is continuous, in which a fibrous band connects the gonads and splenic structures. The other form is discontinuous and separates the mass of the spleen which has jointed to the gonadal structure. The first form is accompanied by fetal abnormalities, including organ and small chin defects. Meneses and Ostrowski described the first case of continuous splenic-gonadal joint in a woman as splenic tissue in the ovary in the left ovary [35]. Several features help to distinguish splenosis from splenic-gonadal adherence. In splenosis, the spleen tissue is spread throughout the peritoneal cavity and peritoneal surface in contrast to splenic-gonadal adherence in which it happens in a specific site. Splenic tissue in the splenosis is formed without naval or specific capsule, while splenic-gonadal adherence implies the natural form of the spleen. Since splenosis is usually asymptomatic and may relatively compensate the no spleen state, it is advisable not to remove the asymptomatic splenosis when being faced during the surgery. Splenosis eliminates old blood cells and protects women`s immune function against infections. Significant increase in serum antipneumococcal antibody levels in patients with autotransplantion of spleen suggests that spleen implanted tissues may be useful and prevent systematic non-capsular bacterial infection in people without spleen. The history of the removal of the spleen and the findings of the surgery are the key to the diagnosis [36].
The gold standard for the diagnosis of splenosis is FNA and can be done prior to laparotomy [37]. Other diagnostic methods prior to surgery are TC99-centric and invasive biopsy-direct CTs [38, 39]. Radiological studies and sonography have a limited value in detecting pelvic diagnosis. The findings of the ultrasonography are not specific and reveal the soft and circle masses in different locations. The low density of the spleen tissue makes it difficult to view it in standard radiography. The CT scan identifies the number, shape, size, and location of the mass, but does not reveal its nature, and these radiological and ultrasound images of the mass, show the differential diagnosis of metastatic diseases, abdominal lymphoma, carcinomatosis, hemangiomatosis, peritoneal mesothelium, multi-focal endometriosis, adenoma, primary renal or hepatic malignancy, gliomatous or peritoneal granulomatous, sub-spleen, and adenopathy. MRI shows low-intensity spleen implantation in T1-weighted and high-intensity spleen implantation in T2-weighted, but it is not useful in differential diagnosis [40].
Currently, TC99 is the standard non-invasive diagnostic method for splenosis in which TC99 sulfurous colloid is broken down in the reticuloendothelial system and finds ectopic tissues [14, 41, and 42]. If preoperative diagnosis is done by suitable radionuclide substance in a patient with the history of impact on stomach, an unnecessary laparotomy can be avoided. Some cases of hematological disorders have been reported in patients with splenectomy that describe a functional reticuloendothelial system within the implantation [29, 43]. Barbaros described a case of recurrence of idiopathic thrombocytopenic purpura (ITP) due to spleenosis five years after the laparoscopic spleen removal which was treated by removing the remaining spleen tissue [44].
The mechanism of splenosis is unclear. However, the ability to spleen haemopoiesis in hypoxia and the inevitability of hypoxia due to aging and pathological changes cause intracellular splenosis and the migration of anterior cellular cells through the portal vein followed by a rupture in the spleen and local induction of hematopoiesis by hypoxia [10]. When splenosis is diagnosed, it is necessary to remove it with surgery in symptomatic patients or with complications of splenosis as well as in patients with hematologic disease. Also, in case of unavailability of diagnosis, no available scintigraphy, and suspicion of malignant diseases, removal of spleen is useful.
Conclusion
With the increased incidence of abdominal injuries due to the road accidents and advancing imaging capabilities, splenosis detection may unwillingly cause a large diagnostic problem more than ever. In addition spleen implantation may mistakenly interpreted as a neoplastic lesion or adenopathy. The hypothetical diagnosis can be done in patients with a lack of reticulocytosis and a Hawell-Jolly body in peripheral blood smear and a history of spleen removal or impact to stomach in the past. TC99 is a rare, reliable and non-invasive method in this condition and helps prevent unnecessary abdominal surgery. In order to prevent any possible diagnostic doubt and future invasive investigations, proven splenosis should be recorded in the patient`s medical records.
Acknowledgements
Thanks to the doctors and staff of Department of Infertility and Surgery of Sarem Specialized Hospital and the Sarem Fertility and Infertility Research Center who helped us with collecting patients` information.
Ethical permissions
The case was not found by the authors.
Conflicts of interests
The case was not found by the authors.
Financial support
This study was supported by Sarem Fertility and Infertility Research Center.
Contribution of authors
Abo Taleb Saremi (First author), author of the article/methodology/main author or helper/statistical analyst/author of discussion (%...); Marzieh Zamanian (Second author), author of the article/methodology/main author or helper/statistical analyst/author of discussion (%...); Leila Soltani (third author), author of the article/methodology/main author or helper/statistical analyst/author of discussion (%...); Arash Pooladi (Fourth author), author of the article/methodology/main author or helper/statistical analyst/author of discussion (%...); (Select the role of each person in the production of the article from among specified roles. Select the appropriate role for each person and avoid the selection of all items for all authors, as it will not be acceptable).