Incidental Prostatic Stromal Tumor of Uncertain Malignant Potential (STUMP): Histopathological and Immunohistochemical Findings

Abstract

D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y D e p a r t m e n t o f U r o l o g y , S a p i e n z a R o m e U n i v e r s i t y , R o m e -I t a l y

Clinical and Pathological Features of Prostatic Stromal Tumor of Uncertain Malignant Potential: A Retrospective Study of 23 Chinese Cases

“…In patients with PSS, staining for myogenic antibodies, such as SMA, desmin, muscle, and MyoD1, was positive [11, 12]. Other parameters, such as cellular characteristics, mitotic activity, necrosis, and expansion into the surrounding organs, can also be used to distinguish the 2 diseases [13]. In T2-weighted imaging, PSS often presents as solid lesions with heterogeneous signals [14].…”

“…STUMP showed a mixed or high signal in T2-weighted imaging, while prostate adenocarcinoma showed a low signal in T2-weighted imaging [14]. In rare cases, STUMP may also be concurrent with prostate adenocarcinoma [13]. In addition, STUMP coexisting with PSS also needs to be differentiated from synovial sarcoma, rhabdomyosarcoma, and other sarcomas [15].…”

“…Serum PSA, as a specific marker of prostate adenocarcinoma, is in the normal range or slightly elevated in STUMP patients. This might be because prostatic stromal tumors have no significant effect on prostatic epithelial cells (which produce PSA) or only cause a slight increase in PSA by tissue compression [13]. STUMP showed a mixed or high signal in T2-weighted imaging, while prostate adenocarcinoma showed a low signal in T2-weighted imaging [14].…”

Stromal Tumor of Uncertain Malignant Potential of the Prostate

“…Parameters used to differentiate these 2 processes include cellularity, mitotic activity, necrosis, and extension into surrounding organs. 4 The etiology and pathogenesis of STUMP is unknown, and no confirmed risk factors have been identified. A small number of cases are diagnosed in the setting of a concurrent prostatic adenocarcinoma.…”

“…A small number of cases are diagnosed in the setting of a concurrent prostatic adenocarcinoma. 4 Owing to the rarity of these tumors, the classification, expected clinical course, and treatment recommendations are still a matter of debate.…”