Scrotal mass differential diagnosis
Jump to navigation
Jump to search
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Niloofarsadaat Eshaghhosseiny, MD[2] Preeti Singh, M.B.B.S.[3]
Overview
Scrotal masses must be differentiated from other diseases that cause scrotal swelling,scrotal pain,such as testicular tortion ,epididimitis,testicular tumors,inguinal herniation and many other diseases.
Differentiating Scrotal masses from the other Diseases
Scrotal masses must be differentiated from other diseases that cause scrotal swelling,scrotal pain,such as testicular tortion ,epididimitis,testicular tumors,inguinal herniation and many other diseases.
- The table below summarizes the findings that differentiates scrotal mass according to the clinical features, laboratory findings, imaging features, histological features, and genetic studies.
Diseases | Clinical manifestations | Para-clinical findings | Gold standard | Associated | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Symptoms | Physical examination | ||||||||||||||
Lab Findings | Past Medical History | Histopathology | |||||||||||||
Unilateral /Bilateral swelling | Onset | Fever | Urinary symptoms | Tender -ness |
Erythema | Discharge | Inguinal Lymphadenopathy | Cremasteric Reflex | Blood/Urine Analysis | Doppler U/S | |||||
Painful | |||||||||||||||
Epididymitis[1][2] [3][4][5][6][7][8] |
Unilateral | Gradual | ± | Dysuria, frequency, and/or urgency | + | - | +
(Pyuria Bacteriuria) |
Painful local lymphadenopathy | + |
|
|
|
|
|
|
Orchitis | Bilateral | Abrupt | ± | Dysuria | + | - | ± | Painful local lymphadenopathy | + |
|
|
|
|
|
|
Testicular Torsion[15][16][17][18][19][7] | Unilateral | Sudden | - | Absent | + | + | +
Blood in semen may be present |
Absent | - |
|
|
|
|
| |
Hematocele[20][21] [22][23][24] |
Unilateral or bilateral | Sudden | - | Absent | + | + | +
Blood in semen |
Absent | - |
|
Scrotal wall thickening and testicular hematoma | Testicular trauma related to:
|
|
|
_ |
Incarcerated Hernia[25][26] | Unilateral | Sudden | + | Absent | + | + | - | Absent | + |
|
|
- | - |
|
|
Brucellosis[27][28][29][30] | Unilateral or Bilateral | Sudden | ± | Dysuria | - | - | ± | Painful local lymphadenopathy | + |
|
|
- |
|
|
Antibodies are detected using:
|
Torsion of the appendix testis[31][32][33][34] | Unilateral or Bilateral | Sudden | - | Absent | + | - | - | Absent | + |
|
|
- |
|
|
|
Henoch-Schonlein purpura[35][36][37][38] | Unilateral | Sudden | - | Absent | + | + | - | - | - |
|
- |
|
|
Biopsy |
|
Fournier's gangrene[39][40][41][42] | Bilateral | Sudden | + | Absent | + | + | - | - | + |
|
- | - | - |
|
|
Diseases | Unilateral /Bilateral swelling | Onset | Fever | Urinary symptoms | Tender<be>-ness | Erythema | Discharge | Inguinal Lymphadenopathy | Cremasteric Reflex | Blood/Urine Analysis | Doppler U/S | Past Medical History | Histopathology | Gold standard | Additional findings |
Painless | |||||||||||||||
Fragile X Macroorchidism[43][44][45][46] | Bilateral | Gradual | - | Absent | - | - | + | Absent | + |
|
- | - | Increased volume of testis |
|
|
Testicular Tumors[47][48][49][50] | Unilateral or bilateral | Gradual | ± | Absent | ± | + | Present | + |
|
- | - | Seminoma shows findings such as:
|
|
| |
Hydrocele[51][52][53][54][55] | Bilateral | Gradual | - | Absent | - | - | - | Absent | + | - |
|
- | - |
|
|
Varicocele[56][57][58][59] | Unilateral
(Mainly left) |
Gradual | Local warmth | Absent | - | ± | - | Absent | + |
|
|
|
- |
|
|
Spermatocele[60][55][61] | Unilateral | Gradual | - | Absent | - | - | - | Absent | + | - |
|
|
|
|
|
Scrotal edema[62][63] | Bilateral and can extend to perineum | Gradual | - | Absent | - | - | - | Absent | + |
|
|
|
- |
|
|
Sebaceous cyst[64][65][66] | Unilateral | Gradual | - | Absent | - | - | - | Absent | + | - |
|
- |
|
|
|
Carcinoma of the scrotum[67][68][69] | - | Gradual | - | Absent | - | - | - | Absent | + | - |
|
- |
|
|
|
Chylocele (Filariasis)[70][71][72] | Unilateral or Bilateral | Gradually
Rapidly |
+ | Absent | - | - | - | Absent | + |
|
|
- | - |
|
|
Scrotoliths[73][74][75] | Unilateral | Gradual | - | Absent | - | - | - | Absent | + | - |
|
|
- |
|
|
References
- ↑ Yu KJ, Wang TM, Chen HW, Wang HH (2012). "The dilemma in the diagnosis of acute scrotum: clinical clues for differentiating between testicular torsion and epididymo-orchitis". Chang Gung Med J. 35 (1): 38–45. PMID 22483426.
- ↑ Manavi K, Turner K, Scott GR, Stewart LH (May 2005). "Audit on the management of epididymo-orchitis by the Department of Urology in Edinburgh". Int J STD AIDS. 16 (5): 386–7. doi:10.1258/0956462053888853. PMID 15949072.
- ↑ Lee YS, Kim SW, Han SW (2018). "Different managements for prepubertal epididymitis based on a preexisting genitourinary anomaly diagnosis". PLoS ONE. 13 (4): e0194761. doi:10.1371/journal.pone.0194761. PMC 5905873. PMID 29668706.
- ↑ Ralls PW, Jensen MC, Lee KP, Mayekawa DS, Johnson MB, Halls JM (June 1990). "Color Doppler sonography in acute epididymitis and orchitis". J Clin Ultrasound. 18 (5): 383–6. PMID 2161009.
- ↑ Michel V, Pilatz A, Hedger MP, Meinhardt A (2015). "Epididymitis: revelations at the convergence of clinical and basic sciences". Asian J. Androl. 17 (5): 756–63. doi:10.4103/1008-682X.155770. PMC 4577585. PMID 26112484.
- ↑ Tracy CR, Costabile RA (April 2009). "The evaluation and treatment of acute epididymitis in a large university based population: are CDC guidelines being followed?". World J Urol. 27 (2): 259–63. doi:10.1007/s00345-008-0338-0. PMID 19002691.
- ↑ 7.0 7.1 7.2 Pepe P, Panella P, Pennisi M, Aragona F (October 2006). "Does color Doppler sonography improve the clinical assessment of patients with acute scrotum?". Eur J Radiol. 60 (1): 120–4. doi:10.1016/j.ejrad.2006.04.016. PMID 16730939.
- ↑ 8.0 8.1 Ludwig M (April 2008). "Diagnosis and therapy of acute prostatitis, epididymitis and orchitis". Andrologia. 40 (2): 76–80. doi:10.1111/j.1439-0272.2007.00823.x. PMID 18336454.
- ↑ Davis NF, McGuire BB, Mahon JA, Smyth AE, O'Malley KJ, Fitzpatrick JM (April 2010). "The increasing incidence of mumps orchitis: a comprehensive review". BJU Int. 105 (8): 1060–5. doi:10.1111/j.1464-410X.2009.09148.x. PMID 20070300.
- ↑ CHARNY CW, MERANZE DR (July 1948). "Pathology of mumps orchitis". J. Urol. 60 (1): 140–6. PMID 18873054.
- ↑ Bjorvatn B (1973). "Mumps virus recovered from testicles by fine-needle aspiration biopsy in cases of mumps orchitis". Scand. J. Infect. Dis. 5 (1): 3–5. PMID 4580293.
- ↑ Beard CM, Benson RC, Kelalis PP, Elveback LR, Kurland LT (January 1977). "The incidence and outcome of mumps orchitis in Rochester, Minnesota, 1935 to 1974". Mayo Clin. Proc. 52 (1): 3–7. PMID 609284.
- ↑ Gall EA (July 1947). "The Histopathology of Acute Mumps Orchitis". Am. J. Pathol. 23 (4): 637–51. PMC 1934294. PMID 19970951.
- ↑ Başekim CC, Kizilkaya E, Pekkafali Z, Baykal KV, Karsli AF (2000). "Mumps epididymo-orchitis: sonography and color Doppler sonographic findings". Abdom Imaging. 25 (3): 322–5. PMID 10823460.
- ↑ Hazeltine M, Panza A, Ellsworth P (2017). "Testicular Torsion: Current Evaluation and Management". Urol Nurs. 37 (2): 61–71, 93. PMID 29240370.
- ↑ Estremadoyro V, Meyrat BJ, Birraux J, Vidal I, Sanchez O (February 2017). "[Diagnosis and management of testicular torsion in children]". Rev Med Suisse (in French). 13 (550): 406–410. PMID 28714632.
- ↑ Sharp VJ, Kieran K, Arlen AM (December 2013). "Testicular torsion: diagnosis, evaluation, and management". Am Fam Physician. 88 (12): 835–40. PMID 24364548.
- ↑ Mikuz G (1985). "Testicular torsion: simple grading for histological evaluation of tissue damage". Appl Pathol. 3 (3): 134–9. PMID 3842075.
- ↑ Gunther P, Schenk JP, Wunsch R, Holland-Cunz S, Kessler U, Troger J, Waag KL (November 2006). "Acute testicular torsion in children: the role of sonography in the diagnostic workup". Eur Radiol. 16 (11): 2527–32. doi:10.1007/s00330-006-0287-1. PMID 16724203.
- ↑ Bowen DK, Gonzalez CM (2014). "Intratesticular hematoma after blunt scrotal trauma: a case series and algorithm-based approach to management". Cent European J Urol. 67 (4): 427–9. doi:10.5173/ceju.2014.04.art24. PMC 4310892. PMID 25667770.
- ↑ Askari R, Khouzam RN, Dishmon DA (2017). "Image Diagnosis: Rapidly Enlarging Scrotal Hematoma: A Complication of Femoral Access?". Perm J. 21. doi:10.7812/TPP/16-111. PMC 5469436. PMID 28609265.
- ↑ Mizutani Y, Miyakawa M (February 1991). "[A case of idiopathic chronic scrotal hematocele]". Hinyokika Kiyo (in Japanese). 37 (2): 199–201. PMID 2048502.
- ↑ Kratzik C, Hainz A, Kuber W, Donner G, Lunglmayr G, Frick J, Schmoller HJ (November 1989). "Has ultrasound influenced the therapy concept of blunt scrotal trauma?". J. Urol. 142 (5): 1243–6. PMID 2681835.
- ↑ Rao MS, Arjun K (October 2012). "Sonography of scrotal trauma". Indian J Radiol Imaging. 22 (4): 293–7. doi:10.4103/0971-3026.111482. PMC 3698892. PMID 23833421.
- ↑ Jenkins JT, O'Dwyer PJ (2008). "Inguinal hernias". BMJ. 336 (7638): 269–72. doi:10.1136/bmj.39450.428275.AD. PMC 2223000. PMID 18244999.
- ↑ Berger D (2016). "Evidence-Based Hernia Treatment in Adults". Dtsch Arztebl Int. 113 (9): 150–7, quiz 158. doi:10.3238/arztebl.2016.0150. PMC 4802357. PMID 26987468.
- ↑ Kaya F, Kocyigit A, Kaya C, Turkcuer I, Serinken M, Karabulut N (March 2015). "Brucellar Testicular Abscess Presenting as a Testicular Mass: Can Color Doppler Sonography be used in Differentiation?". Turk J Emerg Med. 15 (1): 43–6. doi:10.5505/1304.7361.2014.82698. PMC 4909939. PMID 27331193.
- ↑ Navarro-Martínez A, Solera J, Corredoira J, Beato JL, Martínez-Alfaro E, Atiénzar M, Ariza J (December 2001). "Epididymoorchitis due to Brucella mellitensis: a retrospective study of 59 patients". Clin. Infect. Dis. 33 (12): 2017–22. doi:10.1086/324489. PMID 11698991.
- ↑ Colmenero JD, Muñoz-Roca NL, Bermudez P, Plata A, Villalobos A, Reguera JM (April 2007). "Clinical findings, diagnostic approach, and outcome of Brucella melitensis epididymo-orchitis". Diagn. Microbiol. Infect. Dis. 57 (4): 367–72. doi:10.1016/j.diagmicrobio.2006.09.008. PMID 17141451.
- ↑ Reisman EM, Colquitt LA, Childers J, Preminger GM (April 1990). "Brucella orchitis: a rare cause of testicular enlargement". J. Urol. 143 (4): 821–2. PMID 2313817.
- ↑ Rakha E, Puls F, Saidul I, Furness P (August 2006). "Torsion of the testicular appendix: importance of associated acute inflammation". J. Clin. Pathol. 59 (8): 831–4. doi:10.1136/jcp.2005.034603. PMC 1860437. PMID 16569689.
- ↑ Kadish HA, Bolte RG (July 1998). "A retrospective review of pediatric patients with epididymitis, testicular torsion, and torsion of testicular appendages". Pediatrics. 102 (1 Pt 1): 73–6. PMID 9651416.
- ↑ Okui N, Tomita K, Kimura A, Uekane K, Kawamura T, Teshima S (September 1994). "[Heterochronic occurrence of bilateral torsion of appendix testis a case report]". Nippon Hinyokika Gakkai Zasshi (in Japanese). 85 (9): 1395–8. PMID 7967303.
- ↑ Lev M, Ramon J, Mor Y, Jacobson JM, Soudack M (October 2015). "Sonographic appearances of torsion of the appendix testis and appendix epididymis in children". J Clin Ultrasound. 43 (8): 485–9. doi:10.1002/jcu.22265. PMID 25704247.
- ↑ Choong CS, Liew KL, Liu PN, Kuo TU, Su CM (July 2000). "Acute scrotum in Henoch-Schönlein purpura". Zhonghua Yi Xue Za Zhi (Taipei). 63 (7): 577–80. PMID 10934812.
- ↑ Modi S, Mohan M, Jennings A (May 2016). "Acute Scrotal Swelling in Henoch-Schonlein Purpura: Case Report and Review of the Literature". Urol Case Rep. 6: 9–11. doi:10.1016/j.eucr.2016.01.004. PMC 4855902. PMID 27169017.
- ↑ Dayanir YO, Akdilli A, Karaman CZ, Sönmez F, Karaman G (2001). "Epididymoorchitis mimicking testicular torsion in Henoch-Schönlein purpura". Eur Radiol. 11 (11): 2267–9. doi:10.1007/s003300100843. PMID 11702171.
- ↑ Akgun C (2012). "A case of scrotal swelling mimicking testicular torsion preceding Henoch-Schönlein vasculitis". Bratisl Lek Listy. 113 (6): 382–3. PMID 22693978.
- ↑ Voelzke BB, Hagedorn JC (April 2018). "Presentation and Diagnosis of Fournier Gangrene". Urology. 114: 8–13. doi:10.1016/j.urology.2017.10.031. PMID 29146218.
- ↑ Huang CS (March 2017). "Fournier's Gangrene". N. Engl. J. Med. 376 (12): 1158. doi:10.1056/NEJMicm1609306. PMID 28328332.
- ↑ Yücel M, Özpek A, Başak F, Kılıç A, Ünal E, Yüksekdağ S, Acar A, Baş G (September 2017). "Fournier's gangrene: A retrospective analysis of 25 patients". Ulus Travma Acil Cerrahi Derg. 23 (5): 400–404. doi:10.5505/tjtes.2017.01678. PMID 29052826.
- ↑ Namkoong H, Ishii M, Koizumi M, Betsuyaku T (February 2016). "Fournier's gangrene: a surgical emergency". Infection. 44 (1): 143–4. doi:10.1007/s15010-015-0816-4. PMID 26138056.
- ↑ Hagerman RJ, McBogg P, Hagerman PJ (June 1983). "The fragile X syndrome: history, diagnosis, and treatment". J Dev Behav Pediatr. 4 (2): 122–30. PMID 6348096.
- ↑ de Vries BB, Halley DJ, Oostra BA, Niermeijer MF (July 1998). "The fragile X syndrome". J. Med. Genet. 35 (7): 579–89. PMC 1051369. PMID 9678703.
- ↑ Lachiewicz AM, Dawson DV (June 1994). "Do young boys with fragile X syndrome have macroorchidism?". Pediatrics. 93 (6 Pt 1): 992–5. PMID 8190590.
- ↑ Saldarriaga W, Tassone F, González-Teshima LY, Forero-Forero JV, Ayala-Zapata S, Hagerman R (2014). "Fragile X syndrome". Colomb. Med. 45 (4): 190–8. PMC 4350386. PMID 25767309.
- ↑ Shen J, Bi Y, Wang X, Lu L, Tang L, Liu Y, Chen H, Zhang B (December 2017). "Epidemiologic study of 230 cases of testicular/paratesticular tumors or masses: 15-year experience of a single center". J. Pediatr. Surg. 52 (12): 2056–2060. doi:10.1016/j.jpedsurg.2017.08.027. PMID 28967388.
- ↑ Hohšteter M, Artuković B, Severin K, Kurilj AG, Beck A, Šoštarić-Zuckermann IC, Grabarević Ž (August 2014). "Canine testicular tumors: two types of seminomas can be differentiated by immunohistochemistry". BMC Vet. Res. 10: 169. doi:10.1186/s12917-014-0169-8. PMC 4129470. PMID 25096628.
- ↑ McDonald MW, Reed AB, Tran PT, Evans LA (2012). "Testicular tumor ultrasound characteristics and association with histopathology". Urol. Int. 89 (2): 196–202. doi:10.1159/000338771. PMID 22677786.
- ↑ Naouar S, Braiek S, El Kamel R (June 2017). "Testicular tumors of adrenogenital syndrome: From physiopathology to therapy". Presse Med. 46 (6 Pt 1): 572–578. doi:10.1016/j.lpm.2017.05.006. PMID 28549629.
- ↑ Costantino E, Ganesan GS, Plaire JC (May 2017). "Abdominoscrotal hydrocele in an infant boy". BMJ Case Rep. 2017. doi:10.1136/bcr-2017-220370. PMID 28551604.
- ↑ Kaefer M, Agarwal D, Misseri R, Whittam B, Hubert K, Szymanski K, Rink R, Cain MP (October 2016). "Treatment of contralateral hydrocele in neonatal testicular torsion: Is less more?". J Pediatr Urol. 12 (5): 306.e1–306.e4. doi:10.1016/j.jpurol.2015.07.009. PMID 26708803.
- ↑ Yang DM, Kim HC, Lim JW, Jin W, Ryu CW, Kim GY, Cho H (2007). "Sonographic findings of groin masses". J Ultrasound Med. 26 (5): 605–14. PMID 17460003.
- ↑ Chen Y, Wang F, Zhong H, Zhao J, Li Y, Shi Z (December 2017). "A systematic review and meta-analysis concerning single-site laparoscopic percutaneous extraperitoneal closure for pediatric inguinal hernia and hydrocele". Surg Endosc. 31 (12): 4888–4901. doi:10.1007/s00464-017-5491-3. PMID 28389795.
- ↑ 55.0 55.1 Rioja J, Sánchez-Margallo FM, Usón J, Rioja LA (June 2011). "Adult hydrocele and spermatocele". BJU Int. 107 (11): 1852–64. doi:10.1111/j.1464-410X.2011.10353.x. PMID 21592287.
- ↑ Clavijo RI, Carrasquillo R, Ramasamy R (September 2017). "Varicoceles: prevalence and pathogenesis in adult men". Fertil. Steril. 108 (3): 364–369. doi:10.1016/j.fertnstert.2017.06.036. PMID 28865534.
- ↑ Yang DM, Kim HC, Lim JW, Jin W, Ryu CW, Kim GY, Cho H (2007). "Sonographic findings of groin masses". J Ultrasound Med. 26 (5): 605–14. PMID 17460003.
- ↑ Locke JA, Noparast M, Afshar K (October 2017). "Treatment of varicocele in children and adolescents: A systematic review and meta-analysis of randomized controlled trials". J Pediatr Urol. 13 (5): 437–445. doi:10.1016/j.jpurol.2017.07.008. PMID 28851509.
- ↑ Shridharani A, Owen RC, Elkelany OO, Kim ED (2016). "The significance of clinical practice guidelines on adult varicocele detection and management". Asian J. Androl. 18 (2): 269–75. doi:10.4103/1008-682X.172641. PMID 26806081.
- ↑ Yang DM, Kim HC, Lim JW, Jin W, Ryu CW, Kim GY, Cho H (2007). "Sonographic findings of groin masses". J Ultrasound Med. 26 (5): 605–14. PMID 17460003.
- ↑ Yeh HC, Wang CJ, Liu CC, Wu WJ, Chou YH, Huang CH (July 2007). "Giant spermatocele mimicking hydrocele: a case report". Kaohsiung J. Med. Sci. 23 (7): 366–9. doi:10.1016/S1607-551X(09)70423-1. PMID 17606432.
- ↑ Geffre M, Maki C, Maier S (March 2017). "Acute Scrotal Edema in Cirrhotic after Laparoscopic Cholecystectomy". Am Surg. 83 (3): e93–95. PMID 28316300.
- ↑ Esposito F, Sanchez O, Siebert JN, Manzano S (October 2018). "Acute scrotal idiopathic edema: A misleading erythema". CJEM. 20 (S2): S37. doi:10.1017/cem.2017.343. PMID 28625172.
- ↑ Solanki A, Narang S, Kathpalia R, Goel A (September 2015). "Scrotal calcinosis: pathogenetic link with epidermal cyst". BMJ Case Rep. 2015. doi:10.1136/bcr-2015-211163. PMC 4593290. PMID 26400592.
- ↑ Prasad KK, Manjunath RD (August 2014). "Multiple epidermal cysts of scrotum". Indian J. Med. Res. 140 (2): 318. PMC 4216510. PMID 25297369.
- ↑ Ząbkowski T, Wajszczuk M (July 2014). "Epidermoid cyst of the scrotum: a clinical case". Urol J. 11 (3): 1706–9. PMID 25015622.
- ↑ Casasola Chamorro J, Gutiérrez García S, de Blas Gómez V (July 2011). "Scrotal carcinoma". Arch. Esp. Urol. 64 (6): 541–3. PMID 21791720.
- ↑ Halfya A, Elmortaji K, Redouane R, Fethi M, Rafik A, Mohamed E, Abdessamad C (2015). "[Squamous cell carcinomas of the scrotum: about 7 cases with review of the literature]". Pan Afr Med J (in French). 20: 163. doi:10.11604/pamj.2015.20.163.5991. PMC 4469445. PMID 26113906.
- ↑ Armas-Alvarez AL, Salinas-Sánchez AS, Atienzar-Tobarra M, Virseda-Rodríguez JA (March 2016). "Scrotal tumors". Arch. Esp. Urol. 69 (2): 86–9. PMID 26959967.
- ↑ Otabil KB, Tenkorang SB (March 2015). "Filarial hydrocele: a neglected condition of a neglected tropical disease". J Infect Dev Ctries. 9 (5): 456–62. doi:10.3855/jidc.5346. PMID 25989164.
- ↑ Janssen KM, Willis CJ, Anderson M, Gelnett MS, Wickersham EL, Brand TC (July 2017). "Filariasis Orchitis-Differential for Acute Scrotum Pathology". Urol Case Rep. 13: 117–119. doi:10.1016/j.eucr.2017.04.002. PMC 5426035. PMID 28507911.
- ↑ Yagain K, Mathew M (February 2011). "Filariasis presenting as a scrotal nodule in a 2 year old child: a case report". Asian Pac J Trop Med. 4 (2): 167–8. doi:10.1016/S1995-7645(11)60062-X. PMID 21771446.
- ↑ Khallouk A, Yazami OE, Mellas S, Tazi MF, El Fassi J, Farih MH (2011). "Idiopathic scrotal calcinosis: a non-elucidated pathogenesis and its surgical treatment". Rev Urol. 13 (2): 95–7. PMC 3176555. PMID 21935341.
- ↑ Noël B, Bron C, Künzle N, De Heller M, Panizzon RG (July 2006). "Multiple nodules of the scrotum: histopathological findings and surgical procedure. A study of five cases". J Eur Acad Dermatol Venereol. 20 (6): 707–10. doi:10.1111/j.1468-3083.2006.01578.x. PMID 16836500.
- ↑ Polk P, McCutchen WT, Phillips JG, Biggs PJ (September 1996). "Polypoid scrotal calcinosis: an uncommon variant of scrotal calcinosis". South. Med. J. 89 (9): 896–7. PMID 8790314.