CARCINOMA PROSTATE PRESENTINGAS A PARAVESICAL MASS - An Interesting Case
SV Mehta*, S Somani*, AA Bokil*, JB Bhawani**, M Patil***, PJ Chibber****
*Senior Resident; **Lecturer; ***Assistant Honorary; ****Honorary Professor and Head of the Department, Sir JJ Group of Hospitals, Mumbai 400 008.
Cystic degeneration of pelvic lymphnodes in prostatic carcinoma is rare. Immunohistochemistry with prostate specific antigen level of the cyst fluid adds another dimension to the investigative or in difficult cases.
Prostate cancer is the second leading cause of cancer death in the male population with 95% being diagnosed between the age group of 45-89. The median age at diagnosis is 72. In most of the cases, major tumour mass is located in the peripheral zone of the gland, followed by the transitional zone. The most frequent sites of metastatic prostate cancer are lymphnodes followed by bone. Lung metastasis are common in patients with bony involvement. The bladder, liver and adrenal gland are the next common organs of involvement.
Prostate cancer is histologically graded by the Gleasonís sum score which is a summation of Gleasonís grade. Gleasonís grade is determined by the level of differentiation of the tumour found on low magnification. Both primary and secondary architectural patterns are identified and assigned a grade from 1 to 5. Gleasonís sum score of greater than 7 is associated with poor prognosis. With poorly differentiated tumour, it may not be possible to identify tissue of origin on histology, especially if the area of controversy involves the bladder neck, prostate and rectum.
Cystic degeneration of lymph nodes is very rare. Rarity of this entity makes this case report interesting.
A 72 year old male presented with obstructive and irritative voiding symptoms of 5 yrs. duration, aggravated over 3 months. He had left calf pain, was investigated for the same and found to have deep vein thrombosis. He was on oral anticoagulants when he presented to us.
Rectal examination revealed a hard glandular enlargement with obliteration of the lateral sulci and ulceration of the rectal mucosa with non tender rectal nodules. A cystic mass was felt in the pelvis, free from the rectal wall and was fluctuant. Its dimensions could not be determined on rectal examination. He had no lymphadenopathy and rest of the clinical examination did not reveal any abnormality.
The patient was investigated, urine examination was normal as were the haematological profile, renal functions and liver functions. Serum prostate specific antigen (PSA) was 18 ng/ml. Ultrasonography of the abdomen and pelvis showed a paravesical cyst measuring 6 cm x 8.5 cm with mixed density and internal mobile echoes suggestive of clots or debris. The mass was separate from the bladder, indenting its walls but not communicating with it. A CT scan showed enlarged pelvic lymph nodes with a large paravesical cyst measuring 7 cm x 8.5 cm (Fig. 1). The cyst had a solid component which was non-enhancing with contrast.
Prostatic Biopsy showed a poorly differentiated tumour arising from the prostate or rectum. Due to the high grade of malignancy it was impossible to determine the tissue of origin on transrectal, trucut biopsy with routine and H and E sections. Hence an immunohistochemistry for PSA staining was undertaken, which was positive for prostatic tissue (Fig. 2). A diagnosis of prostatic cancer was made and the patient subjected to bilateral
Fig 1 Paravesical cystic mass with solid component within.
orchidectomy with an objective of controlling this androgen dependent tumour. However the cyst did not regress over 3 wk. following orchidectomy. This cyst was aspirated transabdominally under ultrasound control. The fluid was blood stained. It was subjected to culture, sensitivity and PSA levels. No organisms were grown and PSA levels were 64,000 ng/ml. The cyst did not recur and the patient has been on follow up since, with no progression of symptoms.
Poorly differentiated tumours of the kind mentioned above, make determination of the organ of origin difficult in view of 2 contiguous organs being involved. (In this case, the rectum and the prostate). Due to the equivocal findings on rectal examination and subsequently on routine H and E staining of tissue obtained on transrectal trucut biopsy, the organ responsible for this malignancy could only be determined by immunohistochemistry for PSA and subsequently PSA levels in the cyst fluid aspirated.
Fig 2 Immunohistochemistry for P.S.A.
PSA levels of 18 ng/ml are not always diagnostic of poorly differentiated malignant tumours of this kind. Also this level of serum PSA is compatible with benign prostatic hyperplasia in very large prostates and requires correlation with prostate size (PSA density). Estimation of free and bound serum PSA levels can further help in subjectively differentiating benign from malignant enlargements, but was not done in this case.
The cyst was a degenerative change in the pelvic lymph nodes. This is a rare association with prostate cancer. These set of findings make this case report interesting.
- Campbellís urology. 7th edition, WB Saunders Co. Philadelphia. 1998.