Editor: Mahmut Akgul (

2022-23/June 13

Contributors: Parnaz Daneshpajounejad, Casey Morrison, Paul Zhang, Kumarasen Cooper, Priti Lal, and Reba E. Daniel

Man in his 30s, non-smoker, initially presented with hematuria, dysuria, and constipation was diagnosed with urothelial carcinoma of bladder on transurethral resection of bladder tumor (TURBT) at an outside hospital. Upon transferring care, patient underwent a subsequent radiology work up which revealed a large vascular mass involving prostate and pushing against bladder base. He underwent systematic prostate needle biopsies. The TURBT from outside hospital was also obtained and reviewed.



a) Paraganglioma

b) Alveolar rhabdomyosarcoma

c) Alveolar soft part sarcoma

d) Metastatic adenocarcinoma

e) Granular cell tumor

Alveolar soft part sarcoma

The patient with a diagnosis of urothelial carcinoma of bladder made at an outside institution, was transferred to our hospital for further care. In-house imaging revealed a large prostate mass impinging on the bladder. Systematic prostate needle biopsies performed in-house revealed moderately differentiated vascular malignant epithelioid neoplasm with cord like and nested growth pattern. The tumor was composed of eosinophilic cells with abundant cytoplasm, mild to moderate pleomorphism, and low mitotic activity.

A differential diagnosis of carcinoma, paraganglioma, and sarcoma was considered. Accordingly, a wide panel of immunohistochemical stains were performed. The tumor cells were negative for all keratin stains including PANCK, CAM5.2, HMWK and AE1/3. Furthermore, the tumor was negative for NKX3.1, PSA, SALL4, GATA 3, HMB45, Melan A, SOX 10, S100, chromogranin, and synaptophysin. The rich vasculature was highlighted by ERG and CD31, however the tumor cells were negative.

Subsequently, a differential diagnosis of sarcoma was included and a workup was performed. The tumor was positive for SMA, while negative for Desmin and Myogenin. TFE3 break apart fluorescence in situ hybridization (FISH) was positive. Further molecular work up revealed presence of an ASPSRC1 gene rearrangement and a final diagnosis of alveolar soft part sarcoma was made. The patient was later diagnosed with bilateral lung metastases. At last follow up, the patient was started on pazopanib and was being followed closely for possible brain metastasis.

Primary alveolar soft-part sarcoma (ASPS) of prostate is an extremely rare entity. To the best knowledge, only two other case reports are in the English literature.

1. Wang JR, Rao Q, Li H, Wang YH, Sun Y, Si HP, Shen LS, Liu CY, Zhang YF. Alveolar soft-part sarcoma of the prostate: a case report and review of the literature. Int J Clin Exp Pathol. 2018 Oct 1;11(10):5126-5132.

2. Chen J, Chen X, Wang Y, Chen H, Wang Z. Imaging Findings and Histologic Appearances of Alveolar Soft Part Sarcoma in the Prostate: A Case Report and Review of the Literature. Clin Genitourin Cancer. 2015 Aug;13(4):e315-e319.

3. Wang XT, Xia QY, Ni H, Wang ZY, Ye SB, Li R, Wang X, Lv JH, Shi SS, Ma HH, Lu ZF, Shen Q, Zhou XJ, Rao Q. Xp11 neoplasm with melanocytic differentiation of the prostate harbouring the novel NONO-TFE3 gene fusion: report of a unique case expanding the gene fusion spectrum. Histopathology. 2016 Sep;69(3):450-8.

4. Spector RA, Travis LW, Smith J. Alveolar soft part sarcoma of the head and neck. Laryngoscope. 1979 Aug;89(8):1301-6.

Parnaz Daneshpajouhnejad, Casey Morrison, Paul Zhang, Kumarasen Cooper,Priti Lal, Reba E. Daniel
University of Pennsylvania Department of Pathology


ASPS, Alveolar soft-part sarcoma, prostate, TFE 3, ASPSRC1