Endometriosis of colon as a cause mimicking Crohn’s disease: a potential pitfall in diagnosis

Endometriosis is a common condition in many women of child-bearing age. Its most common site is the perito- neal cavity. Endometriotic foci can also be found in many other organs, such as the lung, urinary bladder, retroperi- toneal space and alimentary tract [1-7]. However, the colon is the most common ectopic focus. Colonic endometriosis has already been described but there is still a rare type of this condition that imitates Crohn’s disease. This work presents the case of a long-term disease that was first di- Przegl¥d menoP auzalny 2/2013 164 agnosed and treated as Crohn’s disease. In the third year of observation, diagnostics and treatment, the disease was recognised properly as colonic endometriosis. Case report A 50-year-old woman presented in hospital for sur- gery due to polypoid changes in the colon within 20-30 cm from the edge of the anus. For a few years, the patient had complained of the pain in the abdomen with concur- rent diarrhoea and transient bleeding from the colon. Pre- viously, the patient was diagnosed (ultrasound, CT scan – NAD) and underwent colonoscopy with a histopatho- logical examination (result no. 100165823/26.02.2009 – Morbus Crohn). The patient was treated for colitis for ap- proximately 3 years. The medication prescribed through that period comprised mesalasine, corticosteride and iron preparations. After about a year, another sample for histopathological investigation was collected during a routine examination on 08.10.2010 (Fig. 1). The result, no. 100314786/14.10.2010, was ambiguous – the mucosa with a slight dysplasia in the enlarged glands. Numerous branching capillaries were found in the lamina propria, Fig. 3. Mucosal inflammation from 08.10.2012 effusions and an inflammatory infiltration of granulo- cytes and lymphocytes, as well as oedema. No final di- agnosis was reported. The patient was still treated for an inflammatory bowel disease (IBD). Another endosco- py was performed on 30.11.2010 (Fig. 2). Histopathologi- cal result no. 3677/2010/KOL showed a slight oedema of the mucosa and focal fibrosis of the lamina propria, as well as a granulocytic infiltration with a crypt abscess.

The material could not be qualified to differentiate between an inflammation, adenoma, and secondary lesions or dysplasia. The patient was still treated for Crohn’s disease. The pain did not subside, the medica- ments were continuously prescribed. The next histo- pathological examination, no. 100429689/23/01/2012, was conducted on 13.01.2012 (Fig. 3) and revealed the mucosa and submucosa of the colon with endome- triotic foci, which were mainly located within the sub- mucosa. Estrogen receptors (+), CD10 (+), CK7 (+) and CK20 (–) were found. The patient was referred for a sur- gical procedure at the local department. On admission, her vital signs and physical exami- nation were normal. The laboratory studies were as follows: WBC (white blood cells) 11 160/mm 3, Hb (he- moglobin) 12.8 g/dl, platelets 339 000/mm3, AST (aspar- tate transaminase) 20 IU/l, ALT (alanine transaminase) 11 IU/l, alkaline phosphatase 68 IU/l, total bilirubin 0.48 mg/dl, total protein 6.9 g/dl, albumin 3.5 g/dl, CRP (C-reactive protein) 18.0 mg/dl, and prothrombin time of 13.4 seconds. The viral marker tests, including HBsAg, anti-HBsAb and anti-HCV, were all negative. The pa- tient underwent a laparoscopic resection of the por- tion of the colon. No postoperative complications were noticed. Two days following the operation, the patient was released from hospital for further monitoring at surgical and gynaecological clinics. The patient’s further recovery was uneventful. Fig. 1. View of colonoscopy from 08.10.2010 Fig. 2. View of colonoscopy from 30.11.2010 Przegl¥d menoP auzalny 2/2013 165

Endometriosis was first described by Shroen in 1690, yet its signs and symptoms were discussed not earlier than in 1769 by Duff. Endometriosis is defined as an atypical hyperplasia endometrium outside the uter- ine cavity [8]. Mainly, the disease affects women, how- ever, there have been some cases of endometriosis in men with prostate cancer [9]. The disease can be found throughout the length of both the small and large in- testines [2-4, 10]. A clinical examination and interview are crucial in the diagnostics. In addition, ultrasound or CT scan of the abdomen are performed. With the development of modern techniques, endoscopic ultrasound and EUS – guided FNA are used in the diagnostics of the lesions located in the lower part of the colon [11]. In some cases, Multislice CT enteroclysis is used [12]. A proper diagnos- tic process is followed by a laparoscopic resection of the colon, which is a method of choice in colonic en- dometriosis [13]. This technique is widely available and not encumbered with many complications. Recently, the results of several studies have been published on the use of robotic surgery and robotic assisted surgery [14]. Although these techniques merely support the clas- sical laparoscopy, their results are very promising. The presented case is interesting insofar that the 3-year diagnostics could not provide a final diag- nosis. Throughout the 3-year-long diagnostic process (Crohn’s disease) the patient was subject to inappropri- ate treatment. There are many descriptions in the lit- erature of forms of endometriosis that simulate other diseases. Either through its symptoms and signs or its clinical picture, endometriosis can imitate other dis- eases with similar signs and symptoms. Samet et al. [15] discuss colonic endometriosis, which perfectly imi- tates colon cancer: the lesion was not found to differ from the cancer under virtual endoscopy. Another ex- ample of imitation can be seen in another case oppo- site to the one described here. Teke et al. [16] presented the case of a young woman with Crohn’s disease situ- ated in the colon, with concurrent polyps that narrowed the intestine and a regular monthly rectal haemor - rhage. In endoscopy, the picture showed endometrio- sis in this part of the colon. The patient was subject to hemicolectomy. The postoperative histopathological examination excluded the preliminary diagnosis and confirmed Crohn’s disease. Difficulties in diagnosing this disease entity are still present, yet now they are not so often, possibly due to more detailed diagnostics and histopathological exami- nations: a good example of this is the case presented within this study. The ultrasound and CT scans did not reveal any lesions. The picture revealed by endoscopy was similar to the picture of a different bowel inflam- mation. Often histopathology did not provide any firm evidence. Detailed receptor tests facilitated a correct diagnosis. All in all, the diagnosis of endometriosis can cause a tremendous difficulty even to an experienced en- doscopist, gynaecologist, surgeon or pathologist. The di- agnostic process can be long while an individually con- ducted examination may not provide an unequivocal diagnosis. In each dubious case every possible diagnostic method, including a repetitive microscopic examination and surgery, should be incorporated.

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