Urinary bladder xanthomatous cystitis.

Xanthoma cystitis of urinary bladder is a rare entity and may present as an intravesical mass. A 38-year-old female presented with abdominal pain and imaging was done which was suggestive of a malignant mass with surrounding tissue infiltration. Partial cystectomy was performed, and histological examination of the mass showed xanthomatous cystitis.

INTRODUCTION

Xanthomas are nonneoplastic, reactive tumor-like processes, usually arising in response to lipid profile disturbances, diseases with secondary hyperlipidemia, like primary biliary cirrhosis and diabetes mellitus and occasionally in normolipidemic states. However, only 50% of patients have hyperlipidemia. It has been suggested that endothelial, stromal, histiocytic and rarely, epithelial cells may be transformed into xanthoma cells. Xanthomas can also be secondary to local surgeries, trauma, or inflammation.[1] Xanthomata occur more frequently in the skin, tendons, subcutaneous tissue and gastrointestinal tract, but, unlike them, urinary bladder xanthoma appears to be a rare condition, and 12 cases have been reported in English medical literature so far.[2]

CASE REPORT

A 38-year-old female presented with lower abdominal pain for 2 months. The patient had no significant medical or surgical history in the past except for tubal ligation done 5 years back as a measure of family planning. Physical examination was unremarkable with no lymphadenopathy or organomegaly. Urinary cytology showed no malignant cells and culture failed to grow any organisms. Ultrasound scan of the abdomen showed 7 × 4 cm size mass lesion in relation to anterior wall of the bladder. Contrast-enhanced computed tomography abdomen and pelvis showed irregular thick wall enhancing area with internal nonenhancing area in the anterosuperior wall of the bladder with perivesical fat stranding and extension of lesion into the right rectus abdominis muscle suggestive of malignant mass of possibly bladder or urachal origin with multiple enlarged enhancing lymphnodes in pre/paraaortic and iliac regions suggestive of metastasis. A flexible cystoscopy examination revealed 6 × 5 cm mass on the dome of the bladder. Blood counts, lipid profile and other hematological and biochemical investigations were within normal limits. Transurethral resection of the bladder mass was done, and histological examination lesion showed urothelial papilloma. Magnetic resonance imaging abdomen and pelvis of the patient was performed postoperatively which showed approximately 61 × 23 × 43 mm sized enhancing polypoidal mass lesion involving anterosuperior wall of bladder on the right side, the mass appeared hypointense on T1WI and T2WI and showed enhancement on post contrast study, there was focal loss of fat plane of the mass anteriorly suggestive of involvement of perivesical fat with invasion of perivesical fat, bilateral recti and subcutaneous fat present, there was peripheral rim enhancement with central nonenhancing necrotic areas, there was loss of fat plane with uterus and right fallopian tube, multiple enlarged pre/paraaortic, bilateral iliac and inguinal lymph nodes were noted [Figure 1a]. Contrast-enhanced computed tomography abdomen + pelvis showed irregular thick wall enhancing area with internal nonenhancing area in anterosuperior wall of bladder with perivesical fat stranding and extension of lesion in the right rectus abdominis muscle [Figure 1b]. We performed a partial cystectomy [Figure 1c and d], and histological examination of the mass showed xanthomatous cystitis [Figure 2]. Postoperative period was uneventful, and the patient was discharged. The patient is kept on follow-up for every 3 monthly; however, long-term follow-up is not mandatory as it is a benign condition with no malignant potential.

Figure 1

(a) Magnetic resonance imaging abdomen + pelvis – 61 × 23 × 43 mm sized enhancing polypoidal mass lesion involving anterosuperior wall of bladder on right side with focal loss of fat plane of the mass anteriorly with multiple enlarged pre/paraaortic, bilateral iliac, and inguinal lymph nodes were noted, (b) contrast-enhanced computed tomography abdomen + pelvis - irregular thick wall enhancing area with internal nonenhancing area in anterosuperior wall of bladder with perivesical fat stranding and extension of lesion in the right rectus abdominis muscle (c) Intraoperative photograph (d) postoperatively specimen photograph

Figure 2

Histopathopathological image - showing xanthoma cells with all layers of urinary bladder

DISCUSSION

Patients with bladder xanthomas are often asymptomatic or may present with hematuria or lower abdominal pain.[3] In most cases, the lesions were located in the dome of the bladder. When large, the lesion may mimic malignancy, clinically and radiologically. Conservative treatment with antibiotics does not resolve these lesions and complete surgical resection is advised. Some authors advocate follow-up cystoscopy since xanthoma may complicate a bladder tumor.[4] However, others are of the opinion that long-term follow-up is unnecessary as the lesion remains static and is not premalignant.

The differential diagnosis on gross appearance includes malakoplakia, which can only be excluded by histological examination.[3] Histologically, foamy cells in the bladder mucosa can occur in xanthogranulomatous cystitis, malakoplakia, atypical mycobacterial infection, and signet ring cell carcinoma. The histiocytes in malakoplakia are associated with small basophilic extracellular or intracytoplasmic calcospherules called Michaelis-Gutmann bodies which stain positive for Von Kossa stain, iron, and periodic acid-Schiff. The differences between xanthoma and xanthogranulomatous cystitis are that the latter consists of xanthoma cells with multinucleated giant cells and chronic inflammatory cells, while the former comprises neither chronic inflammatory cells nor giant cells. From the literature review, it seems that urinary bladder xanthoma is slightly more common in women than in men. The main clinical symptoms are hematuria, abdominal pain, or urinary retention. The coexistence of xanthoma and carcinoma in a bladder diverticulum has been documented, as bladder xanthoma can develop adjacent to urothelial cell carcinoma.[5] However, the pathogenesis of peritumoral xanthoma has not yet been established. Treatment in the presence of symptoms and no other lesion to account for them may require complete transurethral resection. On the other hand, urinary bladder xanthoma does not cause symptoms, and after checking the lipid profile, long-term follow-up is not mandatory, as urinary bladder xanthoma has no malignant potential. In summary, urinary bladder xanthoma is a distinctive, rare clinical entity that should be considered.

CONCLUSION

Diagnosis of xanthomatous cystitis is difficult preoperatively, and the condition may be mistaken for malignancy. Surgical resection is curative with no postoperative recurrence reported. Simple excision may suffice for a localized xanthoma, but if the disease is combined with an urachal remnant or adenoma, partial cystectomy is preferred.