International Journal of Surgery 9 (2011) 117e121 Contents lists available at ScienceDirect International Journal of Surgery journal homepage: www.theijs.com Review Primary subcutaneous hydatid cysts: A review of 22 cases Cuneyt Kayaalp *, Abuzer Dirican, Cemalettin Aydin Inonu University, Department of General Surgery, Malatya, Turkey article info abstract Article history: Received 22 January 2010 Received in revised form 25 August 2010 Accepted 5 October 2010 Available online 25 October 2010 Keywords: Echinococcus Hydatid Cyst Soft tissue Subcutaneous Aim: We aimed to review cases of primary subcutaneous hydatid cysts whether this is a fearsome disease or a benign progressed pathology. These cysts are rare, have difficulty in diagnosis and management, particularly for inexperienced clinicians. Methods: We searched key words of "echinococcosis, hydatid, soft tissue, subcutaneous, cutaneous" at MEDLINE/PUBMED. We eliminated unrelated articles, cases with primary visceral hydatid focus or muscular cysts. Twenty publications including 22 patients were suitable for analysis. We contacted with authors of the articles for missing data. Follow-up periods and recurrences were updated. Results: All patients were from endemic areas and most from rural regions (90%). Most frequent locations were thigh (27%) and gluteal region (9%). Mean size was 5.7 þ 3.1 cm (2e15 cm). Main symptom (70%) was painless, slow growing mass with normal overlying skin. Serologic tests were usually negative (79%). Only 45% of the patients were diagnosed as hydatid cyst before treatment. Most cases (91%) were treated by surgical excision and spillage occurred at 25% of them. Cyst pouchs were irrigated with protoscolocidal solutions after cyst removal. There was no anaphylaxis during procedures. There was no recurrence with a mean follow-up of 26 þ 18 months (6e60 months). Conclusion: Primary subcutaneous hydatid cyst should be in mind for differential diagnosis of soft tissue masses particularly for patients who lived in regions where hydatid cyst is endemic. There is no reported anaphylaxis or recurrence during diagnostic or therapeutic interventions. Complete excision is the best treatment option. Primary subcutaneous hydatid cysts generally look like a benign progressed disease. Ó 2010 Published by Elsevier Ltd on behalf of Surgical Associates Ltd. 1. Introduction Hydatid cyst disease is an endemic parasitic infestation caused by Echinococcus granulosus and it is an important public health problem in the Mediterranean countries, Middle East, Africa, South America, Asia and Australia. 1 Main hosts for Echinococcus granulosusis are dogs and human contacts with the disease after oral intake of infected dog feces. After ingestion of the eggs to the portal venous system, liver becomes the most frequently involved organ (60e70%) and lungs are the second most common site (5e27%). 1 If parasite passes liver and lungs, it may locate in any organ. 2e5 Primary subcutaneous hydatid disease means that there is not any primary focus of hydatidosis. This is a rare disease and can have difficulties in diagnosis and management, particularly for inexperienced clinicians. Even in the endemic areas, detection of a subcutaneous hydatid cyst results with apprehension for anaphylaxis or local/systemic recurrences. We experienced with two cases of subcutaneous hydatid cysts and despite our * Corresponding author. Department of General Surgery, Staff Surgeon of Gastrointestinal Surgery, Turgut Ozal Medical Center, Inonu University, Malatya, Turkey, 44315. Tel.: þ90 422 341 0660/3706; fax: þ90 422 341 0229. E-mail addresses: ckayaalp@inonu.edu.tr, cuneytkayaalp@hotmail.com (C. Kayaalp). fears, patients demonstrated uneventful progress in the short and long term follow-up. Then we decided to review whether a subcutaneous hydatid cyst is a fearsome disease or a benign progressed pathology. For the first time, we reviewed the available literature regarding with primary subcutaneous hydatid cysts and we aimed to demonstrate the demographic features, diagnosis, risks, treatment and results. 2. Material and methods In September 2008 and 2009 for two separate times, wesearchedthe key words of [(echinococ* OR hydati*) AND (soft tissue* OR subcutaneous* OR cutaneous*)] at PUBMED/MEDLINE and this resulted with 330 articles. We eliminated unrelated articles, cases with concomitant hydatid focus or muscular hydatid cysts. The resulting publications were searched and the references of all articles were cross-checked to decrease the possibility of missing relevant publications. The search revealed 32 publications, of which 20 included suitable data. 6e25 All the publications were case reports between 1994 and 2009. Patient s age, gender, location of cyst, symptoms, signs, size of the cyst, diagnostic radiology, serology, preoperative diagnosis, treatment, adjuvant medications, morbidity, recurrences and follow-up time were recorded. If there were any missing data, we contacted with the authors of articles via e-mail. By this way, the follow-up periods and the recurrences were updated. Data were tabulated in tables, and sum of the colons in the tables and the means were calculated. Chi-square test and student-t test (SPSS 13.0) were used for statistical analysis. 1743-9191/$ e see front matter Ó 2010 Published by Elsevier Ltd on behalf of Surgical Associates Ltd. doi:10.1016/j.ijsu.2010.10.009
118 C. Kayaalp et al. / International Journal of Surgery 9 (2011) 117e121 3. Results There were 22 cases, 15 female and seven male, with a mean age 40 (range between 10e73) (Table 1). All patients were from endemic areas for echinococcosis and the most patients who had available data were from rural area (90%). The most frequent locations for subcutaneous hydatid cysts were thigh (27%) and gluteal region (9%) (Fig. 1). Three (14%) cases were located in head and neck, only one (4.5%) in upper extremities, 11 (50%) in trunk and the remaining seven (31.5%) cysts were in lower extremities. Head and neck located cysts were in younger patients than trunk located and lower extremity located cysts (14.0 5.3 years vs. 42.0 4.5 years and vs. 43.1 11.3 years, p ¼ 0.023, p ¼ 0.040 respectively). Mean cyst size was 5.7 3.1 cm (ranged 2e15 cm). Head and neck located cysts were smaller than lower extremity cysts (3.6 0.6 cm vs. 8.0 3.9 cm, p ¼ 0.044). Main symptom (70%) was painless, slow growing mass and only 30% of the patients complained with pain. Pain was more frequent with lower extremity cysts than other locations (57% vs. 10%, p ¼ 0.036). Most cysts (77%) were mobile in subcutaneous fat tissue and sometimes they were fixed to peripheral tissues (23%). Overlying skin was usually normal in appearance (92%) but rarely erythematous. Diagnostic radiology was performed 57% of the patients and the most preferred tool was superficial ultrasound examination (92%). Magnetic resonance imaging (MRI) and computed tomography (CT) were usually preferred after ultrasound examination. Sixty-one percent of the cysts were multiloculated and 33% of them were uniloculated, the remaining 6% were degenerated cysts. Multiloculated cysts were greater than uniloculated cysts (7.1 3.6 cm vs. 4.0 0.9 cm, p ¼ 0.060). Hydatid serologic tests were usually negative (79%) (Table 2). Fine needle aspiration biopsy for diagnosis was performed for five patients and none of them complicated with allergic reactions. Only 45% of the patients were diagnosed as hydatid cysts before treatment. Half of the patients were treated with a diagnosis of soft tissue mass, and rarely the diagnosis was abscess or hernia. Usually general surgeons (59%) and orthopedic surgeons (18%) were related with subcutaneous hydatid cysts. However, other surgeons (plastic, pediatric, thoracic or ear-nose-throat) were faced with subcutaneous hydatid cysts according to cyst locations. Most cases (91%) were treated by surgical excision and spillage occurred at 25% of them without any anaphylactic reactions. Adjuvant treatment with mebendazole or albendazole was administered in 82% of cases and the remaining received no treatment. Recurrence rate was zero after a mean follow-up of 26 18 months (ranged 6e60 months). 4. Discussion 4.1. Mechanism of subcutaneous disease During surgical treatment of hydatid cysts, iatrogenic spillage of cyst contents to incision area can result with secondary subcutaneous hydatid cysts. 26 Sometimes, subcutaneous hydatid cyst can be a part of disseminated (abdominal, thorasic, etc) disease. 27,28 Rarely, spontaneous rupture of a visceral hydatid cyst into subcutaneous tissue can cause subcutaneous hydatid cysts. 29e32 All these are secondary hydatid cysts. The mechanism of primary subcutaneous localization is unclear. There are two potential mechanisms; (a) direct subcutaneous contamination through an injured skin or (b) subcutaneous colonization of ingested eggs after passing liver and lungs. This review demonstrated that hand location was less than thigh or gluteal locations (4.5% vs, 36%). If the direct contamination mechanism was correct, risk of contact should be higher for hands than thigh or gluteus. We believe that subcutaneous colonization of the parasite in the circulation after ingestion is a more reliable mechanism than the direct contact theory. 4.2. Epidemiology of subcutaneous disease We found that incidence of subcutaneous hydatid disease is 1.5% (ranges between 0.6% and 2.6%) among all cases of hydatid disease in endemic areas 2,3,33,34 (Table 3). However, real incidence can be different. Studies in Table 3 include mainly general surgery clinics and this can result in overlooking total number of hydatid patients (thoracic, cranial, etc) in hospitals. Additionally, most soft tissue masses are treated at small medical centers and this can result in under-reported cases Age and sex distribution of subcutaneous hydatid cysts were similar to the liver hydatid cysts. 1 All patients were from endemic areas and most patients were from rural areas. Location around the Table 1 Demographics of the patients with primary subcutaneous hydatid cysts. No Author, year Age/sex Endemic area Living area Location Size* Pain with mass Mobility of mass Overlying skin Radiology Cyst type 1 Chevalier 1994 40/Male Yes NA Thigh 15 cm Yes NA NA US, CT, MRI Multilocular 2 Voucharas 1997 50/Female Yes Rural Thigh 5 cm No Mobile Normal No NA 3 Ok 2000 12/Female Yes NA Submandibular 4 cm No Mobile Normal No Unilocular 4 Ozturk 2001 20/Male Yes Rural Malar 3 cm No Mobile Normal US Unilocular 5 Acar 2001 42/Female Yes Rural Thigh 5 cm Yes Mobile Normal No Multilocular 6 Baldi 2002 54/Female Yes NA Scapula 6 cm NA NA NA No Multilocular 7 Arinc 2003 39/Male Yes Rural Sternum 4 cm No NA NA No Unilocular 8 Orhan 2003 43/Female Yes NA Thigh 5 cm Yes NA Erytematous US Unilocular 9 Guiral 2004 34/Female Yes Rural Knee 11 cm No Mobile Normal US, MRI Multilocular 10 Koybasioglu 2004 22/Female Yes NA Infraumblical 3 cm NA NA NA CT Degenerated 11 Kiyak 2006 62/Female Yes NA Inguinal 4 cm Yes NA NA US NA 12 Gurbuz 2006 10/Female Yes NA Retroauricular 4 cm No Fixed Normal US Multilocular 13 Bedioui 2007 70/Female Yes NA Hypogastric 6 cm NA NA Normal NA Multilocular x 14 Daoudi 2007 21/Female Yes Rural Gluteal 6 cm NA NA NA US, MRI Multilocular 15 Demirel 2007 73/Female Yes NA Subclavicular 5 cm NA NA NA No Unilocular 16 Dogmus 2007 21/Female Yes NA Lumbal 3 cm No Mobile NA US Multilocular 17 Safioleas 2008 73/Male Yes NA Gluteal 6 cm No Mobile NA US Multilocular 18 Parsak 2008 29/Female Yes NA Thigh 6 cm Yes Fixed NA US, MRI Multilocular 19 Dirican 2008 64/Male Yes Rural Thigh 9 cm No Mobile Normal US,CT Multilocular 20 Dirican 2008 67/Male Yes Rural Palm 3 cm No Fixed Normal No Unilocular 21 Gupta 2008 12/Female Yes Rural Shoulder 2 cm No Mobile Normal No NA 22 Gupta 2008 20/Male Yes Urban Back 10 cm No Mobile Normal No NA US: Ultrasound, CT: Computed tomography, MRI: Magnetic resonance imaging, x Including calcification, NA: Not available. * Largest diameter.
C. Kayaalp et al. / International Journal of Surgery 9 (2011) 117e121 119 Fig. 1. Location of subcutaneous cysts. Numbers are correlated with Table 1 and sizes of the cysts are proportional with a 180 cm height man. trunk and roots of limbs could be explained due to an increase in vascularization and less muscular activity in these areas. 35 Head and neck cysts were smaller than trunk and lower extremity cyst, possibly due to earlier admission of the patients with aesthetic anxieties. 4.3. Diagnosis Most patients complained of slow growing, painless, mobile masses with normal overlying skin. radiological evaluation can provide diagnosis. radiological findings of a thick cyst wall, calcification, daughter cysts, and a germinative membrane separate from the cyst wall are findings specific to hydatid cysts. 1 AmericanCollege of radiology has guidelines for soft tissue masses and, if a soft tissue mass is not related with bone (X-ray negative) they usually recommend MRI for the first study to order and ultrasound or CT recommended for the alternative methods. 36 in this review of subcutaneous hydatid cysts, the most preferred radiological method was ultrasound. we believe that ultrasound in experienced hands is useful for diagnosis. MRI and CT are both useful to demonstrate relationship of cyst to adjacent organs. Routine laboratory tests generally do not show any specific results for hydatid cysts. Serologu is a useful tool particularly for the differential diagnosis of hydatid liver cysts, however, it is usually negative (%79) for subcutaneous hydatid cysts The differential diagnosis of the soft tissue masses included abscess, sebaceous cyst, lipoma, tuberculous abscess, aneurysm, hernia, sarcoma, chronic hematoma, synovial cyst and necrotic soft tumor. Previously, we thought that preoperative correct diagnosis of a subcutaneous hydatid cyst was mandatory for the risks of anaphylaxis or recurrences due to spillage. This review demonstrated that the preoperative diagnosis was accurate in only 45% of the patients. Despite this low diagnostic rate, there were no early or late complications such as anaphylaxis or recurrences. We believe that preoperative definitive diagnosis is not always necessary. After diagnosis of subcutaneous hydatid cyst, radiological screening of the body should be done to look for another focus. 4.4. Treatment and results Hydatid liver cyst is traditionally treated by surgery, but recently minimal invasive percutaneous treatment options are promising. 1 Subcutaneous surgery is less extensive than visceral surgery and complete excision of subcutaneous hydatid cyst is almost always possible contrary to liver hydatid cysts. Subcutaneous cysts were usually multiloculated and percutaneous treatment has a lower success rate for these cysts. Therefore, we believe that subcutaneous hydatid cysts should be treated by total excision. Rupture of the cyst
120 C. Kayaalp et al. / International Journal of Surgery 9 (2011) 117e121 Table 2 Diagnosis, treatment and results of the patients. No Author, year Serology FNAB Preoperative diagnosis Surgical departments Treatment Morbidity Adjuvant treatment Recurrence Follow-up (months) 1 Chevalier 1994 Negative Yes Abscess Orthopedics Excision NA Yes NA NA 2 Voucharas 1997 NA No Soft tissue mass General surgery Excision NA No NA NA 3 Ok 2000 NA No Soft tissue mass General surgery Excision No Yes No 60 4 Ozturk 2001 Negative No Soft tissue mass Plastic surgery Excision NA No No 14 5 Acar 2001 NA Yes Hydatid cyst General surgery Excision No Yes No 6 6 Baldi 2002 NA No Soft tissue mass NA Excision NA NA No 60 7 Arinc 2003 Negative No Hydatid cyst Thorasic surgery Excision NA Yes No 12 8 Orhan 2003 Negative No Hydatid cyst Orthopedics Excision NA Yes No 12 9 Guiral 2004 Negative No Hydatid cyst Orthopedics Excision Spillage Yes No 24 10 Koybasioglu 2004 NA Yes Hydatid cyst General surgery Excision NA NA NA NA 11 Kiyak 2006 Negative No Femoral hernia General surgery Excision NA NA NA NA 12 Gurbuz 2006 NA No Hydatid cyst Ear Nose Throat Excision NA Yes No 12 13 Bedioui 2007 Negative No Soft tissue mass General surgery Excision No NA NA NA 14 Daoudi 2007 Negative No Hydatid cyst Orthopedics Excision NA NA No 36 15 Demirel 2007 Negative No Soft tissue mass General surgery Excision NA No No 6 16 Dogmus 2007 Positive No Soft tissue mass General surgery Excision Spillage Yes No 24 17 Safioleas 2008 Positive No Hydatid cyst General surgery Excision No Yes No 36 18 Parsak 2008 Positive No Hydatid cyst General surgery Excision NA Yes No 12 19 Dirican 2008 Negative No Hydatid cyst General surgery Excision No Yes No 36 20 Dirican 2008 Negative No Soft tissue mass General surgery Excision No Yes No 36 21 Gupta 2008 NA Yes Soft tissue mass Pediatric Surgery Percutaneous NA Yes NA NA 22 Gupta 2008 NA Yes Abscess General surgery Percutaneous NA Yes NA NA FNAB: Fine neddle aspiration biopsy NA: Not available. Table 3 Incidence of primary subcutaneous hydatid cysts. Author, year should be avoided and if occurs, cyst pouch should be irrigated with protoscolocidal solutions after removal of cyst contents. Risk of anaphylaxis or other allergic reactions made us to suggest surgery under general anesthesia instead of local or regional anesthesia. Identifying a subcutaneous hydatid cyst can alert the clinician for disseminated hydatid cysts in the body. If a subcutaneous hydatid cyst was primary and treated by total surgical excision, the prognosis is generally good. There was no recurrence of 22 cases with a mean 26 months follow-up. 5. Conclusion Primary subcutaneous hydatid cyst should be a differential diagnosis of soft tissue masses particularly for patients who lived in regions where hydatid cyst is endemic. There is no reported anaphylaxis or recurrence during diagnostic or therapeutic interventions. Complete excision is the best treatment option. Primary subcutaneous hydatid cysts generally look like a benign disease. Conflict of interest statement None to declare. Funding None. References Total number of hydatid cyst patients Patients with subcutaneous hydatid cysts (%) Department of publication Bal 2008 2 153 4 (2.6%) Pathology Yildirim 2006 3 118 3 (2.5%) Surgery Col 2003 33 176 1 (0.6) Surgery Lazar 1978 34 448 6 (1.3%) Surgery Total 895 14 (1.5%) 1. Kayaalp C. Hydatid cyst of the liver. In: Blumgart LH, Belghiti RJ, DeMatteo RP, Chapman WC, Büchler MW, Hann LE, D Angleca M, editors. Surgery of liver biliary tract and pancreas. 4 th ed. Philadelphia: Saunders Elsevier; 2007. p. 952e70. 2. Bal N, Kocer NE, Arpaci R, Ezer A, Kayaselcuk F. Uncommon locations of hydatid cyst. Saudi Med J 2008;29:1004e8. 3. Yildirim M, Erkan N, Vardar E. Hydatid cysts with unusual localizations: diagnostic and treatment dilemmas for surgeons. Ann Trop Med Parasitol 2006;100:137e42. 4. Kiresi DA, Karabacakoglu A, Odev K, Karakose S. Uncommon locations of hydatid cysts. Acta Radiol 2003;44:622e36. 5. Engin G, Acunas B, Rozanes I, Acunas G. Hydatid disease with unusual localization. Eur Radiol 2000;10:1904e12. 6. Chevalier X, Rhamouni A, Bretagne S, Martigny J, Larget-Piet B. Hydatid cyst of subcutaneous tissue without other involvement: MR imaging features. AJR 1994;163:645e6. 7. Voucharas C, Papaioannidis D, Papamichael K. Subcutaneous mass of the right thigh. Postgrad Med J 1998;74:287e8. 8. Ok E, Sözüer EM. Solitary subcutaneous hydatid cyst: a case report. Am J Trop Med Hyg 2000;62:583e4. 9. Ozturk S, Dever M, Yıldırım S. Hydatid cyst in the soft tissue of the face without any primary. Ann Plast Surg 2001;46:170e3. 10. Acar T, Tacyildiz R, Tuncal S. Isolated hydatid cyst in the subcutaneous tissue. Turk J Med Sci 2001;31:575e6. 11. Baldi A, Rossiello L, Rossiello R, Baldi F. Echinococcal cysts with primary cutaneous localization. Br J Dermatol 2002;147:807. 12. Arinc S, Alper L, Arinc B. Hydatid disease of chest wall: a case report. Gogus Hastalik Derg 2003;14:291e3. 13. Orhan Z, Kara H, Tuzuner T, Sencan I, Alper M. Primary subcutaneous cyst hydatid disease in proximal tight. BMC Musculoskelet Disord 2007;4:25. 14. Guiral J, Rodrigo A, Tello E. Subcutaneous echinococcosis of the knee. Lancet 2004;363(9402):38. 15. Koybasioglu F, Arikok A, Ozturk E, Onal BU. Fine needle aspiration cytology in diagnosis of a subcutaneous echinococcal cyst. Acta Parasitol 2004;49:266e7. 16. Kiyak G, Ozer M, Aktimur R, Kusdemir A. Primary hydatid disease of the soft tissue. Internet J Surg 2006;8:2. 17. Gurbuz MK, Ozudogru E, Calki H, Kabukcuoglu S, Dogan N. A retroauricular situated primary hydatid cyst: a case report. Turk Arch Otolaryngol 2006;44:230e3. 18. Bedioui H, Makni A, Nouira K, Mekni A, Daghfous A, Ayadi S, et al. Subcutaneous hydatid cyst. Case report of an exceptional location. Med Trop 2007;67:181e2. 19. Daoudi A, Loudiyi ElibrahimiA, Elmrini A, Chakour K, Boutayeb F. Solitary subcutaneous hydatid cyst of gluteal area: an unusual lacalization. an case report. Ann Chir Plast 2006;3:448e51. 20. Demirel AH, Akgun A, Ongören AU, Kisakurek M, Erol MF. Unusally located hydatid cysts. J Acad Gastroenterol 2007;6:158e60. 21. Dogmus M, Kaplan M, Salman B, Yılmaz U. Unusual presence of hydatid disease in subcutaneous tissue: a case report. New J Med 2007;24:246e8. 22. Safioleas M, Nikiteas N, Stamatakos M, Safioleas C, Manti CH, Revenas C, et al. Echinococcal cyst of the subcutaneous tissue: a rare case report. Parasitol Int 2008;57:236e8. 23. Parsak CK, Eray IC, Sakman G, Eray SI, Gumurdulu D, Akcam T. Hydatid disease involvement of primary subcutaneous tissue in the posterior proximal thigh. An unusual localization. Int J Dermatol 2008;47:417e8. 24. Dirican A, Unal B, Kayaalp C, Kirimlioglu V. Subcutaneous cysts occurring in the palm and the tight: two case reports. J Med Case Reports 2008;2:273.
C. Kayaalp et al. / International Journal of Surgery 9 (2011) 117e121 121 25. Gupta R, Mathur SR, Agarwala S, Kaushal S, Srivastav A. Primary soft tissue hydatidosis: aspiration cytological diagnosis in two cases. Diagn Cytopathol 2008;36:884e6. 26. Bozkurt AK, Yavuz N, Yüceyar L. Subcutaneous hydatidosis due to iatrogenic spreading of cystic fluid during surgery. J Cardiovasc Surg 2001;42:849e51. 27. Bhattacharya S, Roy CK, Das S, Goswami P, Mondal J, Ghosal DP. A case of disseminated hydatidosis. J Indian Med Assoc 2003;101:672e4. 28. Gonzalez-Ripoll M, Espino R, Gomez J, Martinez R, Fernandez E, Romanos A. Subcutaneous hydatidcyst in multivisceral hydatidosis. Esp Pediatr 1987;27:215e6. 29. Salerno S, Cracolici E, Lo Casto A. Subcutaneous rupture of hepatic hydatid cyst: CT findings. Dig Liver Dis 2006;38:619e20. 30. Kismet K, Ozcan AH, Sabuncuoglu MZ, Gencay C, Kilicoglu B, Turan C, et al. A rare case: spontaneous cutaneous fistula of infected splenic hydatid cyst. World J Gastroenterol 2006;12:2633e5. 31. Parmar H, Nagarajan G, Supe A. Subcutaneous rupture of hepatic hydatid cyst. Scand J Infect Dis 2001;33:870e2. 32. Vahedian-Ardakani J. Hydatid cyst of the liver presenting as cutaneous abscesses. Ann Saudi Med 1997;17:235e6. 33. Col C, Col M, Lafci H. Unusual localizations of hydatid disease. Acta Med Austriaca 2003;30:61e4. 34. Lazar C, Chifan M, Strat V, Dolinescu C, Tircoveanu E, Niculescu D, et al. Unusual localizations of hydatid cysts. Rev Chir Oncol Radiol O R L Oftalmol Stomatol Chir 1978;27:333e7. 35. Garcia-Diez AI, Ros Mendoza LH, Villacampa VM, Cozar M, Fuertes MI. MRI evaluation of soft tissue hydatid disease. Eur Radiol 2000;10:462e6. 36. Berquist TH, Dalinka MK, Alazraki N, Daffner RH, DeSmet AA, el-khoury GY, et al. Soft tissue masses. AmericanCollege of radiology. ACR Appropriateness Criteria. Radiology 2000;215(Suppl):255e9.