Saudi Journal of Kidney Diseases and Transplantation

CASE REPORT
Year
: 2010  |  Volume : 21  |  Issue : 3  |  Page : 518--520

Cystic nephroma: A diagnostic dilemma


Debajyoti Mohanty, Bhupendra Kumar Jain, Vivek Agrawal, Arun Gupta 
 Department of Surgery, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India

Correspondence Address:
Bhupendra Kumar Jain
Department of Surgery, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi
India

Abstract

Cystic nephroma (CN) is a rare benign neoplasm of kidney with excellent prog­nosis. An accurate pre-operative diagnosis differentiating CN from other cystic renal malignan­cies may be impossible by clinical and radiological examination, and histopathological exami­nation provides the final diagnosis. This report describes two adult patients with large multi-locular cystic renal masses on imaging and the diagnosis of CN was clinched post-operatively by the ho­neycomb appearance of the cut specimen and the finding of multiple, non-communicating fluid filled cysts lined by cuboidal or flattened epithelial cells and absence of blastemal cells on mic­roscopy. Tumor diameter on cross sectional imaging remains the key parameter for treatment de­cisions in renal neoplasms, with nephrectomy being preferred for larger lesions.



How to cite this article:
Mohanty D, Jain BK, Agrawal V, Gupta A. Cystic nephroma: A diagnostic dilemma.Saudi J Kidney Dis Transpl 2010;21:518-520


How to cite this URL:
Mohanty D, Jain BK, Agrawal V, Gupta A. Cystic nephroma: A diagnostic dilemma. Saudi J Kidney Dis Transpl [serial online] 2010 [cited 2020 Jul 16 ];21:518-520
Available from: http://www.sjkdt.org/text.asp?2010/21/3/518/62699


Full Text

 Introduction



Multilocular cyst of the kidney or cystic neph­roma (CN) is a rare and benign non-familial renal neoplasm with an excellent prognosis. These tumors may be amenable to renal spa­ring surgery but most patients undergo neph­rectomy in absence of an accurate pre-opera­tive diagnosis. We herewith report two adult patients with CN to highlight the diagnostic di­lemma and management options for this rare tumor.

 Case Reports



Case 1

A 45-year-old lady presented with complaints of intermittent, non-colicky pain in right hypo­chondrium and lumbar region of 12-months duration. Abdominal examination was normal. Ultrasonogram (USG) of the abdomen showed a multi-septate cystic mass measuring 6.5 Χ 5.5 Χ 4.3 cm involving the mid-pole of the right kidney and cholelithiasis. Contrast enhan­ced computed tomogram (CECT) of the ab­domen showed a 6.6 Χ 6.5 Χ 4.4 cm cystic mass with fine internal septations and delayed enhancement of the wall, involving the mid­pole of the right kidney compressing the pelvis and upper ureter [Figure 1]. Urine cytology for malignant cells was negative. Hydatid serolo­gy was within normal range. Right nephrec­tomy and cholecystectomy was performed. The cut section of kidney showed a large cyst con­taining clear fluid with multiple small cystic swellings arising from the wall. The patient was asymptomatic on follow-up after six months.

Case 2

A 25-year-old lady presented with persistent dull aching pain in the right lumbar region for six months with no urinary complaints. Abdomi­nal examination revealed a non-tender, smooth, well defined, rounded lump in the right upper abdomen, that moved with respiration and the upper margin was not reachable. USG of the abdomen showed a multi-septate cystic exo­phytic mass measuring 6 Χ 5.4 Χ 4.7 cm invol­ving the upper and mid-poles of the enlarged right kidney. CECT scan of the abdomen re­vealed a non-enhancing multi-locular cystic mass involving upper pole of the right kidney extending into the middle part, measuring 6.5 Χ 6.0 Χ 4.2 cm with no solid component. No vas­cular invasion, ascites or lymphadenopathy was seen. Urine cytology for malignant cells was negative. Per-operatively, a right renal mass was seen with bosselated surface involving more than upper 2/3 rd of the kidney, with no infil­tration of the Gerota's fascia and no enlarged lymph nodes. A radical nephrectomy was done. The cut surface of the specimen showed multiple cystic spaces, filled with clear fluid like a honeycomb; no solid component was seen [Figure 2]. The patient was well on follow-up after 18 months.

Cystic nephroma was the histopathological diagnosis in both the patients.

 Discussion



Microscopically, CN is characterized by well demarcated, multiple, non-communicating fluid filled cysts lined by cuboidal or flattened epi­thetlial cells, separated by septations and ab­sence of blastemal cells. It has a bimodal dis­tribution with two-thirds of tumors presenting in children between three months and two years, with male predominance and second peak in adults over 30-years of age, with a female pre­dominance. Only 5% of this rare tumor is seen in the 5-30 years age-group. [1]

CN is considered to be a segmental form of renal dysplasia related to polycystic kidney di­sease or maldevelopment of the ureteric bud. It is also regarded as a neoplasm, occurring at the benign end of the wide spectrum of a con­tinuum of renal tumors with cystic variant of Wilms' tumor at the other extreme and cystic partially differentiated nephroblastoma (CPDN) occupying the middle zone. [2]

Flank pain, hematuria, hypertension and uri­nary tract infection are the usual presenting features in adults, [3] while painless abdominal mass is common in children. The CECT and magnetic resonance imaging findings sugges­tive of CN are encapsulated multi-locular cy­stic renal mass with contrast enhancement of septae. [4] Precise pre-operative diagnosis of CN by clinical and radiological means may be im­possible and the final diagnosis is made by surgical excision and histopathological exami­nation. [5] We did not attempt fine needle aspira­tion cytology as the cysts are non-communi­cating and multi-locular resulting in difficulty to obtain adequate tissue for diagnosis. [6] The differential diagnosis includes CPDN, Wilms' tumor with multi cystic changes, and cystic hamartoma of the renal pelvis, clear cell sarco­ma, and multi cystic renal cell carcinoma.

Since there is a wide array of differential diagnosis, to rule out malignancy convincingly is not easy, and the tumor diameter on cross sectional imaging remains the key parameter for treatment decisions. The aggressive poten­tial of small renal cell carcinoma (RCC) in terms of tumor grading and staging increases dramatically beyond a tumor diameter of 3 cm. [7] Nephron sparing surgery can be attempted in CN when the renal mass is [8] and close follow­up with USG or CECT scan is possible. Recur­rence has been reported following in-complete excision and partial nephrectomy. [9] Nephrectomy should be considered for larger lesions and ra­dical nephrectomy, as done in the second case, is indicated if possibility of RCC cannot be excluded.

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