Location

Number of cases

Authors

Retroperitoneum

97

Seco et al [5], Bapat et al [12], Yamakita et al [13], Morishita et al [14], Genoni et al [15], Ng et al [16], Baikovas et al [17], Johnson et al [18], Martino et al [19], Guglielmi et al [20], Ziv et al [21], Gheysens et al [9], Halvic et al [22], Herrada et al [23], Furuhata et al [24], Ebine et al [25], Sadamoto et al [26], Gravalos et al. [27], Iwamoto et al [28], Sanna et al [29], Singletary et al [30], Curciacrello et al [31], Gonzalez Sanchez et al [32], Schutz et al [33], Perez Garcia et al [34], Irsutti et al [35], Parez et al [36], Buchanan et al [37]

Peri-renal

24

Ebisno et al. [38], Inoue et al. [39], Takihara et al. [40],,Feudis et al [41], Barret et al. [42], Okada et al [43], Present two cases

Mesentery

27

Seco et al. [5], Barki et al. [44], Hung et al. [45], Schroff et al. [46], Makipernaa et al. [47], De Heer-Groen et al [48], Parez et al [36], Neerhout et al [49], Powel et al [50], Burke et al [51]

Greater omentum

3

Volta et al [52], Kiguchi et al [53]

Gastric

2

Kiguchi et al [53], Yebra et al [54]

Peri-pancreatic

5

Kiguchi et al [53], Rotman et al [55], Brossard et al [56], Inoue et al [39], Erkan et al [57]

Pancreatic

3

Chaulin et al [58], Corbisier et al [59], Lepke et al [60]

Porta hepatitis

5

Rahmouni et al [61], Farkas et al [62], Peck et al [63], Cirillo et al [64]

Adrenal gland

1

Debatin et al [65]

Pelvis

27

Seco et al [5], Latte et al [66], Daley et al [67], Boxer et al. [68], Tsukamoto et al [69], Luburich et al [70], Isik et al [71], Ylinen et al [72], Schwartz et al [73], Mondal et al [74], Kiguchi et al [53], Calvo Villas et al [75], Mac Donald et al [76], Fields et al [77], Kkasantikul et al [78], Halvic et al [22], Murphy et al [79]

Spleen

1

Taura et al [80]

Total of cases

195

The clinical presentations of CD differ greatly between the localized and the systemic forms (Table 2). The first appears in young generally healthy patients and cause few symptoms 67. Abdominal and retroperitoneal locations, as were our cases, can be associated with mass effect symptoms related to compression of adjacent organs. This could present as: post-prandial discomfort, anorexia, vomiting, weight loss, urinary retention and abdominal or lumbar pain 80. Systemic, or multifocal, CD is associated with systemic disturbance as anemia, increased erythrocyte sedimentation rate, polyclonal hypergammaglobulinemia, hypoalbuminemia and thrombocytopenia which all can be associated with a specific symptoms 678. The clinical picture includes asthenia, fever, weight loss, generalized lymphadenopathy, hepatomegaly, splenomegaly, peripheric edema, pleural effusion, impaired renal function and sometimes polyneuropathy 678. Rarely POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, M protein and Skin change) or amyloidosis may be associated to systemic CD 678.

Radiographic characteristics of CD are non specific, but some features could help to suspect the diagnosis (Table 3) 7780. Plain radiographic finding includes a mass effect and in nearly 30% of localized form calcifications harboring a radial arrangement or star-shaped calcifications which is said to be characteristic of CD 77. Ultrasonography (US) usually demonstrates a hypoechogenic and homogenous mass with quite clear delimitation 83077. US can show central areas of sharp acoustic shadowing due to calcification 30. CT scan show a solid, homogenous and well delimited mass which enhance with vascular contrast as a results of hypervascularity 5307780. It can also show star-shaped microcalcifications which are quite specific on pre-contrast images 52777. Post-contrast IV study, while demonstrating dense enhancement of the mass, could demonstrate a central stellate scar 3080. Angiography shows a strongly hypervascular lesion, which present a dense and homogenous flush during the capillary phase 56840537780. This flush begins in periphery to become diffuse whiting the mass and is specific for the HV type of CD 7780. It can also demonstrate hypertrophied feeding vessel, an useful information when resection is plan 8537780. Magnetic resonance imaging (MRI) characteristics of CD are: hypodense mass on the T1 weighted study and hyperdense lesion on the T2 weighted image sometimes with star-shaped calcifications 607780. Gadolinium injection produces an enhancement which appear in periphery to become diffuse similarly to the flush observed during angiography 7780. All these radiological finding are not specific but some like the star-shaped calcifications and the type of hypervascularisation are quite specific and should alert clinician to the possibility of CD. In summary, in front of an abdominal or retroperitoneal mass which is well delimited, homogenous and harbor star-shaped calcifications and hypervascularisation associated with typical flush, the diagnosis of CD should be strongly suspected 537780. The differential radiological diagnosis is mainly malignant neoplasm because of the hypervascularity 4077, and the fact that 80% of the retroperitoneal tumor are malignant 408182. The major tumors found in the retroperitoneum are soft tissue sarcoma (liposarcoma, fibrosarcoma, leiomyosarcoma, neurofibrosarcoma, undifferentiated and rabdomyosarcoma) which are frequently heterogeneous mass and show necrosis on CT scanner; vascular tumor (hemangiosarcoma and lymphangiosarcoma) which are cystic and of liquid density on USG and CT scanner; and the lymphoma which generally presents as multiple adenopathy and homogeneous mass on CT scanner 3083848586. Urological tumors like seminoma, prostatic cancer and teratoma tends to give rise to metastatic disease in the retroperitoneum in the form of adenopathy which are generally multiple 86. While a preoperative diagnosis of CD is difficult to obtain, fine needle biopsy is not a definitive tools because of there low specificity and the differential diagnosis with lymphoma is impossible by this approach 7788. In addition to be non-specific and rarely yielding enough useful tissue, needle biopsy is associated with tumoral seeding with reported frequency of 1/40 000 to 1/1 000 biopsy 8389. Thus when surgery is planned, indication for fine needle biopsy should be carefully deliberated, while an open biopsy could always be done during surgery 83.

Treatment of CD differs between localized and multifocal, or systemic, forms. The standard therapy of localized form is surgical excision which is curative when resection is complete and en-bloc. No recurrences have been reported after total excision in the literature as it was the case with our cases 567113840538290. Because these lesions are highly vascularised, embolization before surgery could be helpful to minimize blood lost during surgery 553. The problem that is faced during resection is to resolve the differential diagnose between a malignant pathology and CD. Macroscopically it is nearly impossible because CD lesions harbor dense fibrous adherences to adjacent organ and hypervascularization typically seen in malignant pathology 5388290. For this reason peroperative diagnosis by open biopsy is helpful, and necessary in case of CD suspicion. It enables one to avoid extensive resection and especially resection of nearby organ for this benign disorder which does not invade adjacent organ even in case of tight contact 38828390. The five years survival after resection is nearly 100% for the localized form 6. Recurrences have rarely been reported generally when excision was incomplete 6388290. For the systemic form no curative therapies have been found yet. Corticotherapy, immunosuppressive drugs, chemotherapy and radiotherapy have been tried without any convincing results 5679192. The prognosis of this form is poor with a median survival of 30 months 6. However recently, the reports of improvement and prolonged survival after splenectomy have been reported with steroid therapy and chemotherapy this could change the prognosis of the systemic form in the future 9192. Of importance from the surgical point of view is that in these cases the remission was obtained after splenectomy only 91. The systemic, PC type, and extremely rarely the localized, HV type, forms are associated with malignant disorder such as Kaposi's sarcoma, malignant lymphoma and myeloma. This association is stronger in HIV positive patients with CD, for example Kaposi's sarcoma is associated to 13% of case of PC type CD in HIV negative and in 75% of case when HIV positive patients. The association with Kaposi's sarcoma could be explained by the fact that HSV8 is cause in the pathogenesis of these two disorders 7. These neoplasms can appear as late as 8 years after the diagnosis of CD, so a long term follow-up is required in patient in whom the diagnosis of CD has been established 6.