Cystic metastasis of prostate cancer: A case report

Abstract

Rationale: Prostate cancer often metastasizes (most commonly to the pelvic lymph nodes and axial skeleton); however, metastases to the pelvic cavity as a solitary mass are unusual. While metastatic prostate cancer is unconventional in pelvic cavity, cystic pelvic lesions are even more scarce. Accurate identification of cystic metastasis can be helpful in management of prostate cancer.

Patient concerns: A 64-year-old male was admitted to our hospital due to urethral irritation symptom and dysuria.

Diagnosis: In addition to prostate cancer, abdominal computed tomography (CT) scanning and magnetic resonance imaging (MRI) of the prostate revealed that a cystic mass was located at right pelvic cavity. Histopathological examination diagnosed the pelvic cystic mass as metastasis from prostatic cancer. Immunohistochemistry results demonstrated Calretinin (+), D2-40 (-), Ki-67 (10%+), Vimentin (-), CK-pan (+), CK5/6 (-), WT-1 (-), PSA (+), SALL4 (-), Villin (-), CK20 (-), CK7 (-), PAX-8 (-), and TTF-1 (-).

Interventions: The cystic mass was removed. Primary cancer of the prostate was reserved as well. After discharge, the patient underwent in a two-year androgen deprivation therapy (ADT) treatment.

Outcomes: After 13 months of discharge, no disease progression was found in the patient.

Lessons: Although cystic prostate cancer is rare, the occurrence possibility should be considered when cystic lesions are accompanied with prostate cancer.

Figure 1

Abdominal CT scanning and MRI of the prostate. (A, B) The nonenhanced and arterial phase of abdominal CT axial scanning shows that a watery low density was located adjacent to the right iliac vessel. There was no obvious enhancement of the lesion in the arterial phase as well. (C) Venous phase of abdominal CT scanning exhibited that there was no significant enhancement in the cystic lesion of right lower abdomen. The enhancement of right part prostate is slightly obvious. (D) Fat-suppressed T2-weighted sequence presents low signal in the right portion of prostate. CT = computed tomography, MRI = magnetic resonance imaging.

Figure 2

Pathological and immunohistological results. (A) Gleason score was 4 + 3 = 7 (prognostic group III/V), tumor proportion (10/12 mm), and among them, Gleason 4 accounted for about 90% (HE, magnification: 100×). (B) Gleason score was 4 + 3 = 7 (prognostic group III/V), tumor proportion (10/12 mm), and among them, Gleason 4 accounted for about 90% (HE, magnification: 400×). (C) Papillary structure of tumor cells are shown in the upper part of the figure, while glomerular and glandular tubular structures are shown in the lower part (HE, magnification: 400×). (D) Papillary structure of tumor cells (HE, magnification: 400×). (E) Immunohistochemical PSA (+) is shown. (F) Immunohistochemical CK-pan (+) is shown.