Metastatic prostate cancer in a 45-year-old patient: a surprising case

Clinical History

A 45-year-old man presented to the ER with a 5 kg weight loss in 4 months, anorexia, weakness and right inguinal swelling with increased right leg circumference. He did not report fever, pain, night sweats or urinary symptoms.

Imaging Findings

An ultrasound was performed to rule out an inguinal hernia or a deep vein thrombosis.
US depicted multiples enlarged lymph nodes of the right inguinal, right common and external iliac and paraortocaval chains.
A contrast-enhanced CT of the neck, chest, abdomen and pelvis was performed with the suspicion of a lymphoma.
The thoracic study showed left supraclavicular, mediastinal and lower oesophageal lymphadenopathies, with the mediastinal ones surrounding the origin of the left subclavian and vertebral arteries.
The swollen lymph nodes in ultrasound appeared as a big retroperitoneal mass in the abdominal CT, with infiltration and obstruction of both ureters causing a retrograde grade 3 ureteral hydronephrosis.
Bone window CT images demonstrated uncountable sclerotic lesions involving every bone included in the study. This finding was confirmed with a “superscan” pattern in bone scintigraphy.

Discussion

A groin lump in a young patient is most of the times due to an acquired inguinal hernia and, if related to lymphadenopathy in the absence of infectious disease, the differential diagnosis must include lymphoproliferative syndromes and lymphatic metastases. These usually come from primary tumours of the lower extremities or the lower part of the vagina, vulva and penis or the lower part of the rectum and anus [1].
Prostate adenocarcinoma is the most common cancer and the third leading cause of cancer death among Spanish men. The vast majority (90%) of such cancers are diagnosed in men aged 65 years and older, being a very rare finding before the age of 50 [2].
Very few cases (less than 30) have been reported in medical literature with widespread lymphadenopathy as the presenting complaint [3].
In our patient the suspicion of prostate cancer was raised by the osteoblastic metastasis and was confirmed by digital rectal examination, very high level of PSA (833 ng/ml) and prostate biopsy.
Lymphatic metastases of prostate cancer occur via the obturator lymph nodes, inguinal lymphadenopathy without involvement of the pelvic lymph nodes being an uncommon presentation [4].
Despite the small number of such cases reported in medical literature, it is of paramount importance to consider prostate neoplasms in the differential diagnosis of every man presenting to the ED with inguinal lymphadenopathy and to perform at least a digital rectal examination. This is important especially when we consider that prostate cancer age-standardised incidence and mortality rates for men in the whole world in the year 2012 situated this tumour in the second place for the former, after lung cancer, and in the fifth for the latter. Incidence rate is increasing worldwide, while mortality rates slowly diminished in the last years, although only in Western countries [5].

Differential Diagnosis List

Final Diagnosis

Prostate adenocarcinoma with disseminated metastatic disease.

URL:	https://www.eurorad.org/case/12654
DOI:	10.1594/EURORAD/CASE.12654
ISSN:	1563-4086