Phyllodes tumor of the prostate: Long-term followup study of 23 cases
ABSTRACT Phyllodes tumor of the prostate is a rare neoplasm of uncertain malignant potential. We studied a large series of phyllodes tumors to define the combination of histological features that are most useful for predicting patient outcome.
A total of 23 cases were obtained from our collective files from 1973 to 2002, and numerous clinical and pathological features were evaluated. A review of the reported cases of phyllodes tumor of the prostate was done.
Patient age was 25 to 86 years (mean 55) and they usually presented with urinary obstructive symptoms and hematuria. The diagnosis was made in 18 tumors by transurethral resection, in 2 by enucleation, in 1 by tumor resection and in 2 by prostatectomy. We analyzed 5 histological features, including cellularity (scale of 1 to 3), cytologic atypia (scale of 1 to 3), the number of mitotic figures per 10 high power fields, the stroma-to-epithelium ratio (low or high) and necrosis (present or absent). This combination of features revealed that 14 cases were low grade phyllodes tumor, 7 were intermediate grade and 2 were high grade with the high grade cases characterized by increased cellularity, severe cytological atypia, more than 5 mitotic figures per 10 high power fields and a high stroma-to-epithelium ratio, indicating stromal overgrowth. Immunohistochemical studies of 8 tumors revealed consistent, intense cytoplasmic immunoreactivity in stromal cells for vimentin and actin, in luminal epithelial cells for prostate specific antigen, prostatic acid phosphatase and broad-spectrum keratin AE1/AE3, and in basal cells for high molecular weight keratin 34beta-E12. Recurrence was seen in 7 of 14 low grade tumors (50%) and in 1 patient low grade sarcoma emerged with subsequent distant metastases 14 years after initial diagnosis following 5 recurrences. Recurrence was seen in 6 of 7 intermediate grade tumors and low grade sarcoma emerged with subsequent abdominal wall metastases in 1 patient 11 years after initial diagnosis following 3 recurrences. The phyllodes tumor recurred in each patient with high grade tumors with a time to first recurrence of 6 and 0.2 years, respectively. Distant metastases developed in these 2 patients.
Histological grading of prostatic phyllodes tumors is predictive of short-term outcome based on the combination of stromal cellularity, cytological atypia, number of mitotic figures and the stroma-to-epithelium ratio. However, these tumors usually recur after transurethral prostatic resection and they are often locally aggressive with time. The emergence of overt sarcoma and metastatic disease is more frequent than previously recognized. Complete resection at initial diagnosis appears to be indicated.
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- "Malignant tumours of the prostate other than carcinomas are rare , among these primary sarcomas are the most frequently observed. Primary sarcoma tumors of the prostate arise from specialized hormone-dependent mesenchymal cells  and are classified, according to their histology, as stromal tumours of uncertain malignant potential (STUMP) and stromal prostatic sarcoma (PS; namely low grade and high grade)   . We describe a rare case of low-grade stromal sarcoma (LG-PS) of the specialised prostatic stroma, and we also review the literature concerning these tumours. "
ABSTRACT: Primary sarcoma tumours of the prostate are rare and are classified, according to their histology, as stromal tumours of uncertain malignant potential (STUMP) and stromal prostatic sarcoma (PS; low and high grade). We describe a case of a 71-year-old man that developed progressive urinary obstruction symptoms and was subjected to a transurethral prostatic resection (TURP). Histologically, there is a diffuse proliferation of epithelioid and spindle cells that showed rare atypical mitotic figures. Immunohistochemically, the neoplastic cells express diffusely CD34 and focally progesterone whereas no immunoreactivity was seen for cytocheratin, desmin, S-100, Bcl-2, chromogranin, CD117, and actin smooth muscle. A final diagnosis of low-grade prostatic stromal sarcoma (LG-PS) was made. This is a really rare neoplasm; in the literature, in fact, to our knowledge, only 6 cases are described and all of these were alive and free of disease at followup. Our patient too is free of disease at 15 months from the diagnosis.12/2011; 2011:252805. DOI:10.1155/2011/252805
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- "Tumor recurrence after transurethral resection is common , occurring in 65% of patients overall, with recurrence rates from 50% for low-grade tumors to 100% for high-grade tumors . Multiple recurrences are often accompanied by progressively increasing biological aggressiveness and sarcomatous transformation. "
ABSTRACT: Cystic epithelial-stromal tumors of the prostate are rare, with 82 cases reported in literature. These cases have been published under a variety of diagnoses, including phyllodes tumor and prostatic stromal proliferation of uncertain malignant potential as well as a malignant tumor called "prostatic stromal sarcoma". We report a case of a 60-year-old man with the histological diagnosis of phyllodes tumor of the prostate in transurethral resection specimen.Journal of Oncology 12/2009; 2009:241270. DOI:10.1155/2009/241270
Article: The prostate.Ciba clinical symposia 6(2):39-68.