Pediatric Case Report

Granulomatous InflammationMasquerading as an Infected UrachalCyst

Joseph W. McQuaid, Emily F. Gorman, Emilie K. Johnson, and Bartley G. Cilento

Errors in urachal obliteration may result in 4 clinical anomalies: patent urachus, urachal cyst, urachal sinus, or ves-icourachal diverticulum. Despite the fact that urachal cysts are one of the more common of these anomalies, most goundetected, presenting in the setting of infection. There are reports in the literature of cysts misdiagnosed as otherinflammatory processes; however, the converse is reported with less frequency. We present the case of a 3-year-old girlwho was admitted to our institution with a suspected urachal cyst. This was subsequently diagnosed as a granulomatousmass caused by the gram negative bacterium Bartonella. UROLOGY 84: 1496e1498, 2014. � 2014 Elsevier Inc.

he urachus bridges the fetal bladder and theumbilicus.1 A vestigial remnant, it is evidence of

Tthe unification that once existed between 2

separate structures: the cloaca, a precursor to the bladder,and the allantois. Between 4 and 5 months of develop-ment, the fetal bladder descends into the pelvis to restbehind the pubis.1 By the completion of this journey, theurachal lumen involutes, leaving behind a fibrous bandthat occupies the potential midline space between theperitoneum and transversalis fascia.2 Although this pro-cess is successful in the vast majority (98%) of cases, er-rors in urachal obliteration may result in 4 clinicalanomalies: patent urachus, urachal cyst, urachal sinus, orvesicourachal diverticulum.2-4

CASE REPORTA 3-year-old girl with no prior urologic or medical historywas admitted to our institution with the chief complaintof abdominal pain in September, 2013. Her symptomsbegan 14 days before presentation when she complainedof intermittent suprapubic pain made worse by urinationand accompanied by low-grade fevers to 101�F. Duringthe ensuing days, the patient was evaluated by her pri-mary care provider; however, given progression of symp-toms, she presented to our emergency department forfurther evaluation.

On physical examination, the patient was afebrile withstable vital signs, demonstrating mild suprapubic fullnesswith associated tenderness inferior to the umbilicus with

Financial Disclosure: The authors declare that they have no relevant financial interests.From the Department of Urology, Massachusetts General Hospital, Boston, MA; the

Department of Pathology, Boston Children’s Hospital, Boston, MA; and the Depart-ment of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, MAAddress correspondence to: Bartley G. Cilento, M.D., M.P.H., Department of

Urology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue,Boston, MA 02468. E-mail: bartley.cilento@childrens.harvard.eduSubmitted: July 28, 2014, accepted (with revisions): August 5, 2014

1496 ª 2014 Elsevier Inc.All Rights Reserved

deep palpation. Laboratory results revealed a white bloodcell count of 14,000/mm3 and electrolytes that were allwithin normal limits; however, a computed tomographyscan at the time demonstrated a 3.6 � 3.0 � 4.7 cmcomplex mass with peripherally enhancing walls and acentral area of hypoattenuation (Fig. 1). This immedi-ately abutted the anterior and left lateral aspect of thesuperior bladder. The patient was admitted to our servicefor initiation of intravenous antibiotics and infectiousdisease consultation. She was discharged the next day forcompletion of her intravenous antibiotic course.

Seven weeks later, the patient returned for a delayedexploratory laparotomy, which revealed a 4.2-cm friable,white-tan mass adherent to the left lateral aspect of thebladder and extending to the base of the umbilicus.Although intraoperative findings were suggestive of alarge desmoplastic reaction potentially consistent with aninfected urachal cyst, careful review of the specimen bypathology was significant for supparative, necrotizinggranulomatous inflammation. This focal abscess demon-strated marked lymphoplasmacytic and eosinophilic in-filtrates of the bladder wall and adjacent soft tissue(Fig. 2). No acid fast or fungal forms were identified;however, multiple small granular forms consistent withBartonella appeared on the Steiner stain (Fig. 3). Therewas no definitive urachal remnant in this tissue.

COMMENTThe relative incidence of the 4 urachal anomaliesvaries among different studies.2,3 However, it is clearthat urachal cysts, despite being regarded as one of themore common of these abnormalities, are still rareoverall with a demonstrated incidence of 1 in 5000births.5 Most small cysts go undetected, but childrenwith infected cysts may present with a variety ofcomplaints. These include a painful abdominal mass,fever, irritative voiding symptoms, or in the case of cyst

http://dx.doi.org/10.1016/j.urology.2014.08.0030090-4295/14

Figure 1. Complex mass with peripherally enhancing wallsand a central area of hypoattenuation (3.6 � 3.0 � 4.7 cm).

Figure 2. Lymphoplasmacytic and eosinophilic infiltrates ofthe bladder wall and adjacent soft tissue.

Figure 3. Steiner stain revealing multiple small granularforms consistent with Bartonella.

hemorrhage or rupture, peritoneal symptoms.2,4 Infec-ted urachal cysts, if left untreated, may result in a rangeof complications: fistulization to bowel, bladder, or skinas well as mechanical obstruction of the gastrointestinalor genitourinary tracts.5,6

Given their varied presentation, urachal cysts are oftenincorrectly diagnosed preoperatively. This rate of misdi-agnosis has been reported to be as high as 35%, withperforated appendicitis, noneperforated appendicitis, andincarcerated hernias leading the list of differentials.7 Less-frequently infected urachal cysts may be mistakenly iden-tified as Meckel diverticulitis, inflammatory bowel disease,or pelvic inflammatory disease.8 Note the converse—incorrect diagnosis of these aforementioned abdominalprocesses as infected urachal cysts—does not appear tohappen with significant frequency; however, there areisolated reports of appendiceal mucoceles, soft tissue

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sarcomas, and omphalomesenteric ducts being mistakenlydiagnosed as infected urachal remnants.9-11

In the case of this 3-year-old girl, a broad differentialwas carefully considered, and an infected urachal cyst wasconsidered most likely given the presentation and imag-ing findings. Yet, on final pathologic review, no urachalremnant could be found—only a necrotizing granuloma.Given that a postoperative tuburculosis skin test wasnegative for potential mycobacterial infection, it appearsthat the intracellular gram negative bacterium Bartonella,successfully stained in the initial pathologic specimen, wasthe inciting agent. This resulted in a necrotizing, granulo-matous mass masquerading as an infected urachal cyst.

Bartonella is composed of 19 different species includingBartonella henselae, the etiologic agent responsible for cat-scratch disease (CSD).12 CSD classically presents withtender, swollen lymph nodes, and variably with fever.After exposure, it may take 7-14 days for symptoms toappear and as long as 2 months. Cats are the naturalreservoir for B henselae, with fleas serving as a vector oftransmission among cats. Kittens are more likely to carrythe bacteria in their blood and, therefore, are more likelyto transmit the disease. It seems likely that the cat-to-human transmission occurs with the inoculation of fleafeces containing B henselae through a contaminated cat-scratch wound. CSD occurs mostly in temperate cli-mates and predominantly in the autumn and wintermonths. Although multiple antibiotics have been used totreat this condition with unclear benefits, most cases arebenign and self limiting particularly in healthy in-dividuals. On follow-up evaluation, the patient and hermother did report several recent exposures to cats, mak-ing this the most likely mode of transmission of B henselaein this case.

Authors have previously reported the presence of xan-thogranulomatous disease involving the urachus andmuscular wall of the bladder.13 In adults, xanthogranu-lomatous inflammation previously has been mistaken for aurachal adenocarcinoma.14 However, this represents toour knowledge the first case of a granulomatous mass

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masquerading as an infected urachal cyst. Although rare, itshould remind us to consider the granulomatous processesin the differential when considering the diagnosis of aurachal anomaly.

References

1. Pazos HM, Costa WS, Sampaio FJ, et al. Structural and ontogeneticstudy of the urachus in human fetuses. Cells Tissues Organs. 2010;191:422-430.

2. Cilento BG Jr, Bauer SB, Retik AB, et al. Urachal anomalies:defining the best diagnostic modality. Urology. 1998;52:120-122.

3. McCrystal DJ, Ewing MJ, Lambrianides AL. Acquired urachal pa-thology: presentation of five cases and a review of the literature.ANZ J Surg. 2001;71:774-776.

4. Bauer SB, Retik AB. Urachal anomalies and related umbilical dis-orders. Urol Clin North Am. 1978;5:195-211.

5. Allen JW, Song J, Velcek FT. Acute presentation of infected ura-chal cysts: case report and review of diagnosis and therapeutic in-terventions. Pediatr Emerg Care. 2004;20:108-111.

6. Coons BJ, Clark PE, Maynes LJ, et al. Sigmoid-urachal-cutaneousfistula in an adult male. Urology. 2009;73:e5-7.

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7. Minevich E, Wacksman J, Lewis AG, et al. The infected urachalcyst: primary excision versus a staged approach. The J Urol. 1997;157:1869-1872.

8. Ogbevoen JO, Jaffe DM, Langer JC. Intraperitoneal rupture of aninfected urachal cyst: a rare cause of peritonitis in children. PediatrEmerg Care. 1996;12:41-43.

9. Perez Fentes DA, Cortegoso Gonzalez M, Punal Pereira A, et al.[Appendiceal mucocele misdiagnosed with infected urachal cyst: adifferential diagnosis to keep in mind]. Actas urologicas espanolas.2009;33:205-208.

10. Tatenuma T, Sakata R, Sugiura S, et al. [Case of abdominal wallmalignant peripheral nerve sheath tumor which is difficult todistinguish from a urachal disease]. Nihon Hinyokika Gakkai zasshi.2013;104:663-666.

11. Iwasaki M, Taira K, Kobayashi H, et al. Umbilical cyst containingectopic gastric mucosa originating from an omphalomesenteric ductremnant. J Pediatr Surg. 2009;44:2399-2401.

12. Florin TA, Zaoutis TE, Zaoutis LB. Beyond cat scratch disease:widening spectrum of Bartonella henselae infection. Pediatrics.2008;121:e1413-e1425.

13. Carrere W, Gutierrez R, Umbert B, et al. Urachal xanthogranu-lomatous disease. Br J Urol. 1996;77:612-613.

14. Kuo TL, Cheng C. Xanthogranulomatous inflammation of urachusmimicking urachal carcinoma. Urology. 2009;73:443.e13-443.e14.

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