Sarcomatoid Carcinoma, Prostate



Sarcomatoid Carcinoma, Prostate


Gladell P. Paner, MD










Monophasic malignant spindle cell tumor is shown involving the prostate. Other areas of this neoplasm showed typical high-grade adenocarcinoma of the prostate with acinar histology.






Acinar adenocarcinomatous component of SC shows prominent nucleoli, mitoses image, and absence of basal cell layer. Spindle cells surrounding the glands have malignant features.


TERMINOLOGY


Abbreviations



  • Sarcomatoid carcinoma (SC)


  • Carcinosarcoma (CS)


Definitions



  • Malignant biphasic or monophasic neoplasm of prostate, demonstrating epithelial and mesenchymal differentiation by light microscopy or immunohistochemistry



    • CS is employed by some authors for tumors with heterologous sarcomatous elements


    • Rationale for considering SC and CS as single entity is due to similar clinicopathologic features and poor prognosis


ETIOLOGY/PATHOGENESIS


Origin



  • Sarcomatoid dedifferentiation in prostatic carcinoma



    • High proportion of SCs have prior diagnosis of prostate adenocarcinoma


    • Focal immunohistochemical expression of PSA &/or PAP is demonstrated in spindle cells


    • Even with heterologous elements present, spindle cells often express keratin or p63 suggesting common origin with carcinomatous component


    • Loss-of-heterozygosity studies show that carcinomatous and sarcomatoid components are clonally related


  • Possible collision of epithelial and mesenchymal malignant tumors less accepted


Risk Factors



  • Prior diagnosis of prostate adenocarcinoma in almost 1/2 of cases


  • Radiotherapy &/or hormonal therapy for prostate carcinoma may play role in SC development


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Rare


    • Only ˜ 100 cases described in literature


  • Age



    • Mean: 70 years, range: 43-91 years


Presentation



  • Majority present with obstructive urinary symptoms or metastatic disease


  • Uncommonly, tumors are detected in patients with elevated serum PSA level or palpable nodule on digital rectal examination (DRE)


Laboratory Tests



  • PSA serum level may be normal or elevated


Natural History



  • Prior history of prostate adenocarcinoma seen in 48-66%



    • Time interval from prostate adenocarcinoma to diagnosis of SC range from 6 months to 16 years (mean: 6.8 years)


  • About 1/3 of cases arises de novo with no prior history of prostate adenocarcinoma and radiation &/or hormonal therapy


Treatment



  • Current therapies, including multimodality approach, are ineffective, as tumor is high grade


Prognosis



  • Poor outcome


  • Aggressive clinical course characterized by local recurrences and metastasis


  • 1 study reports 5-year cancer specific survival of 41% and 7-year survival of 14%


  • Another study reports actuarial risk of death at 1 year of 20% after diagnosis of SC



  • Systemic metastases in majority of patients are to lungs and bone



    • Other reported sites include brain, lymph node, liver, peritoneum, and skin


MACROSCOPIC FEATURES


General Features



  • Most tumors are encountered in transurethral resection of prostate (TURP) specimens for obstructive urinary symptoms


  • Large gray-white to yellow-tan with prominent necrosis, hemorrhage, and infiltrative growth


  • Tumors extend extraparenchymally into periprostatic soft tissues or adjacent organs, such as seminal vesicles and urinary bladder


MICROSCOPIC PATHOLOGY


Histologic Features

Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Sarcomatoid Carcinoma, Prostate

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