Extraprostatic papillary cystadenocarcinoma of the prostate.

Abstract: A 62-year-old man was evaluated for lower urinary tract symptoms. Imaging studies showed a normal prostate and multiple cysts between the rectum and bladder with no evident communication to the prostate. On pathology, papillary cystadenocarcinoma with positive immunohistochemical staining for PSA was confirmed.

Key Words: prostatic neoplasm, cystadenocarcinoma

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Papillary cystadenocarcinoma of the prostate is an extremely rare tumor, with most of the reported cases originating in Japan. We describe a patient with this unusual neoplasm and review the literature.

Case Report

A 62-year-old man was referred to our institution for voiding dysfunction. Three years earlier, he had been evaluated for lower urinary tract symptoms. Rectal examination was not significant and his PSA level was 8.9 ng/mL. Transrectal ultrasonography (TRUS) showed a normal prostate and multiple cysts between the rectum and bladder. Biopsies of the prostate and cysts were negative for malignancy and nonspecific inflammation, respectively. The patient underwent cyst excision, which revealed a pelvic cystadenoma on pathology. His PSA declined to 2.1 ng/mL in three months, and he remained well until one year ago, when his PSA increased to 47.3 ng/mL. At that time, TRUS and MRI both showed a few pelvic cystic solid masses (up to 7 X 5 X 5 cm) with no communication to a normal-appearing prostate. (Fig. 1A and B). A CT-guided cyst aspiration and biopsy were performed. The cystic fluid was straw-colored, and was positive for malignant cells and a PSA level of more than 5,000 ng/mL. Biopsy revealed papillary cystadenocarcinoma with positive immunohistochemical staining for PSA. Two prostate biopsies were negative for malignancy. A workup for metastasis was negative. The patient's past medical history of diabetes mellitus, cerebrovascular accident and coronary artery bypass grafting made him a poor surgical candidate and he refused surgery. He was placed on oral antiandrogen therapy (flutamide 750 mg/d). At the patient's one year follow-up visit, the pelvic masses had disappeared and the PSA had decreased to 0.2 ng/mL. (Fig. 1C).

Discussion

Periprostatic cystic lesions may be infectious or congenital, or they may result from prostatic retention, parasitic (hydatid) cyst, benign prostatic hyperplasia, cystic carcinoma of the prostate, (1) bone cysts or a variety of benign and malignant tumors. Papillary cystadenocarcinoma has been reported to be among the rarest causes of pelvic cysts. To our knowledge, this is the 16th reported case of a patient with papillary cystadenocarcinoma of the prostate in the literature. In a review of the literature, Naoe et al (2) showed that out of 43 cases of cystic carcinomas of the prostate, 12 were papillary cystadenocarcinoma (27.9%). The term adenoma is applied to any benign epithelial neoplasm that forms glandular patterns. Those that form large cystic masses, as in the ovary, are referred to as cystadenomas. Some tumors produce papillary patterns that protrude into cystic spaces and are called papillary cystadenomas. The malignant form is called cysta-denocarcinoma. (3) Most reported cases have been from Japan with presenting symptoms of hematuria (33%), retention (25%), dysuria (25%) and polyuria (16.7%). Our patient presented with lower urinary tract symptoms. In all of the reported patients except one, the serum PSA increased as a tumor marker. (4) In our patient, the PSA increased in the serum and cystic fluid, and immunohistochemical staining was positive. Although bloody aspirated cystic fluid usually indicates malignancy, our patient had straw-colored cystic fluid that was positive for malignant cells. As found in previous reports, the cyst dimensions in our patient (as determined by CT and MRI scans), measured up to 100 mm. Papillary adenocarcinomas which originate from the prostatic duct are occasionally discernible on cystourethroscopy as they bulge into the urethra. (5) In the current case, cystourethroscopy revealed an enlarged prostate and evidence of extrinsic compression to the base of bladder.

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As papillary cystadenocarcinoma of the prostate is rare, a diagnostic histologic criteria is not yet available. In all reported cases, the diagnosis was based on histologic examination and immunohistochemistry for PSA. What is quite unique to the present case is that there was no overt communication between the cysts and the prostate, clinically or radiologically. Three separate extended prostate biopsies were negative for malignancy. Definitive treatment is not well established. As surgical treatment, transurethral resection has been introduced for tumors confined within the prostatic urethra, although more extensive surgery may be necessary for more invasive forms. (5) Almost all of the cases in the literature were in an advanced clinical stage. Endocrine therapy was chosen in the majority of the cases, whereas radical surgery was performed only in patients with either stage B or C disease. (2) Chemotherapy has been proposed for some patients. In this case, treatment consisted of endocrine therapy alone, and all the cysts disappeared within one year on follow-up MR imaging (Fig. 1C). Long term follow-up is required in these patients, and other treatment approaches may be necessary.

References

1. McDermott VG, Meakem TJ III, Stolpen AH, et al. Prostatic and periprostatic cysts: findings on MR imaging. AJR Am J Roentgenol 1995;164:123-127.

2. Naoe M, Ogawa Y, Fuji K, et al. Papillary cystadenocarcinoma of the prostate. Int J Urol 2004;11:1036-1038.

3. Neoplasia. In: Cotran R, Kumar V, Collins T, eds. Pathologic Basis of Disease, 6th ed. Philadelphia, WB Saunders, 1999, pp 260-328.

4. Kurokawa T, Kato N, Morikawa S, et al. A case of papillary adenocarcinoma of the prostate. Hinyokika Kiyo 2003;49:415-417.

5. Watanabe J, Shimizu Y, Yamamoto S, et al. Papillary adenocarcinoma of the prostate: report of 3 cases. Hinyokika Kiyo 2000;46:273-276.

Raising kids is part joy and part guerilla warfare.
--Ed Asner

Abdol-Mohammad Kajbafzadeh, MD, and Hooman Djaladat, MD

From the Department of Urology, Tehran University of Medical Sciences, Tehran, Iran, and the Department of Urology, Mohammadi Hospital Hormozgan University of Medical Sciences, Bandarabbas, Iran.

Reprint requests to Abdol-Mohammad Kajbafzadeh, MD, No. 36, 2nd floor, 7th Street, Saadat-Abad Avenue, Tehran, 1998714616, Iran. Email: [e-mail]

Accepted April 18, 2006.

RELATED ARTICLE: Key Points

* Papillary cystadenocarcinoma of the prostate is an extremely rare tumor.

* Most of the reported cases have been from Japan.

* PSA is increased in serum and cystic fluid of papillary cystadenocarcinoma.

* The diagnosis is based on histologic examination and immunohistochemistry for PSA.