Small cell carcinoma of the prostate

Small-cell neuroendocrine cancer of the prostate: an atypical presentation of a common disease

A 70-year-old man with a history of prostate cancer, previously submitted to surgical castration and trans-urethral resection of the prostate, was admitted to Accident and Emergency department. He had been suffering from osteoarticular and abdominal pain, and recent weight loss. An abdominal and a pelvic CT showed multiple hepatic metastases and a pelvic mass, but his prostate-specific antigen values were low (0.26 n/mL). A biopsy of a hepatic metastasis and of the pelvic mass revealed a small-cell neuroendocrine prostate cancer, a rare and aggressive androgen-independent form of prostate cancer with a poor prognosis. Our purpose was to report a clinical case of a rare and aggressive variant of a common disease. A high index of suspicion is required to make an early diagnosis and to ensure a proper therapeutic approach.

Small cell carcinoma of the prostate presenting with skin metastasis: a case report

INTRODUCTION

Small cell carcinoma of the prostate is a very rare and aggressive type of prostatic cancer. Most cases are diagnosed at advanced stage due to early metastasis. The bones, liver, regional and distant lymph nodes are the most common sites of metastasis of small cell carcinoma of the prostate. Skin metastasis of small cell carcinoma of the prostate is a very rare entity due to the uncommon metastatic site. Here, we describe the case of a patient with small cell carcinoma of the prostate which metastasized to his skin.

CASE PRESENTATION

A 74-year-old Caucasian man presented to another urology center for mild lower urinary tract symptoms in 2003. His prostate-specific antigen was 23 ng/mL. According to the physical examination signs and prostate-specific antigen, he underwent a transrectal ultrasound-guided prostate biopsy. The pathologic examination of his prostate revealed a Gleason score: 3 + 4 = 7 adenocarcinoma of the prostate. Investigations showed stage T2N0M0 disease and he was treated with radiotherapy to his pelvic lymph nodes and prostate. Six years after the initial diagnosis, he complained of a palpable left-side 2 × 2 cm subcutaneous solitary mass localized just behind his scapula. The results of his laboratory tests including serum acid phosphatase and prostate-specific antigen were in normal ranges. Our general surgery department performed a diagnostic biopsy of the mass and totally excised the lesion. The pathologic examination of the mass showed small cell carcinoma metastasis with chromogranin + and the pathologist advised us to examine the lung or prostate for the primary tumor. The patient undertook a transrectal ultrasound-guided prostate biopsy and the pathologic result revealed small cell carcinoma within residual adenocarcinoma. We investigated the other sites for metastasis and restaging investigations showed a 1cm metastatic lesion in his liver. Our medical oncology department decided to treat him with combination chemotherapy with etoposide and cisplatin in six cycles; however, he died due to disseminated myocardial infarction before starting the fifth combination chemotherapy cycle.

CONCLUSIONS

Clinicians should keep in mind that early diagnosis of this disease is very difficult due to early metastatic spread of small cell carcinoma and lack of concordant elevation of prostate-specific antigen. There is no accepted standard treatment modality for this pathology and overall prognosis is poor.

Premalignant and malignant prostate lesions: pathologic review

BACKGROUND

High-grade prostatic intraepithelial neoplasia (HGPIN) is currently the only recognized premalignant lesion of prostatic carcinoma.

METHODS

This review article discusses HGPIN, its link to prostatic adenocarcinoma, and the significance of its presence on needle biopsy. The criteria and clinical impact of the diagnosis of atypical small acinar proliferation on needle biopsy are reviewed. Certain subtypes of prostate cancer that are not associated with HGPIN are of clinical relevance, and the unique clinicopathologic features of these subtypes are discussed. Histologic variants of prostatic adenocarcinoma with distinct cell types are also described.

RESULTS

HGPIN is the only known pathologic factor currently available to distinguish which patients may be at risk for detecting carcinoma on repeat biopsy. Histologic variants are recognized due to the inference of a particular Gleason grade pattern associated with the cell type, hence affecting prognosis. Typically, pure forms of these histologic variants are associated with worse prognosis due to the associated high Gleason grades.

CONCLUSIONS

HGPIN has a strong association with acinar-type prostatic adenocarcinoma. HGPIN and acinar-type prostatic adenocarcinoma both show similar molecular alterations, providing further evidence of their association.