Large Nodular Fasciitis of the Shoulder Presenting as Soft Tissue Sarcoma: A Case Report.

CASE: This case report describes a patient who presented with clinical and radiographic features of a soft tissue sarcoma of the shoulder. Despite having a painless and relatively large mass, a biopsy and resection revealed nodular fasciitis (NF). CONCLUSION: This is an unusual case of a painless 10 cm mass that histopathologically was diagnosed as NF in the upper extremity with proximity to the axillary nerve and posterior humeral circumflex vessels. The USP6 rearrangement was helpful in confirming the diagnosis. Careful clinical, radiographic, and pathologic correlation is necessary in diagnosing these relatively rare tumors. In cases where there are discordant findings, molecular markers can be very helpful.

"Collecting duct carcinoma of the kidney: diagnosis and implications for management".

Collecting duct carcinoma of the kidney is a rare and aggressive subtype of renal cell carcinoma (RCC) arising from the distal convoluted tubules. At the time of diagnosis, patients are more frequently symptomatic, with advanced locoregional stage, and have metastatic disease. The 2016 WHO Classification of Tumours of the Urinary System defined diagnostic criteria for this entity. However, the diagnostic features continue to evolve, with typical, but not entirely specific, histologic and immunophenotypic characteristics. In addition, the lack of consistent molecular alterations makes collecting duct carcinoma a diagnosis of exclusion, with historical cases being re-classified as fumarate hydratase deficient RCC, ALK rearranged RCC, renal medullary carcinoma or high-grade urothelial carcinoma. The rarity and poor prognosis of the tumor makes it difficult to reach consensus guidelines to guide therapy. In this manuscript we review the clinicopathologic features of collecting duct carcinoma including pathologic diagnostic criteria, molecular characteristics and differential diagnosis, and their possible implications for management.

Utility of GATA-3 and Cytokeratin 5/6 Immunostains in Separating Condyloma Acuminatum Arising in the Urinary Tract From Non-Invasive Papillary Urothelial Carcinoma.

Background Condyloma acuminatum is a squamous epithelial lesion which uncommonly involves the urinary tract. In this location, non-invasive papillary urothelial carcinoma constitutes one of the main differential diagnoses with significant prognostic and therapeutic implications. To date, no ancillary immunohistochemical stain has been described to differentiate these two entities. We assess the utility of cytokeratin 5/6 (CK5/6) and GATA-3 immunohistochemistry in distinguishing condyloma acuminatum from non-invasive papillary urothelial carcinoma. Design We reviewed 9 condylomata acuminata involving the urinary tract, 12 low-grade and 8 high-grade non-invasive papillary urothelial carcinomas. CK5/6 immunostaining was performed in all cases. GATA-3 immunostaining and low-risk human papilloma virus (HPV) chromogenic in situ hybridization was performed in all condyloma cases and 2 urothelial carcinomas with squamous differentiation. Results 8/9 condylomata acuminata were positive for low-risk HPV. All condylomata acuminata exhibited strong full-thickness cytoplasmic staining for CK5/6. In 10 of 12 low-grade non-invasive papillary urothelial carcinomas, CK5/6 expression was continuous and limited to the basal cell layer, while it was patchy and limited to the basal cell layer in all 8 high-grade non-invasive papillary urothelial carcinomas. Two low-grade non-invasive papillary urothelial carcinomas showed focal full-thickness CK5/6 expression in the areas of squamous differentiation. These 2 cases were negative for low-risk HPV. GATA-3 immunostaining was positive in all condylomata acuminata. Conclusions CK5/6 immunostaining is a useful and simple tool that can help separate low-grade and high-grade non-invasive papillary urothelial carcinomas from condyloma acuminatum involving the urothelium-lined organs. GATA-3 has no discriminatory role between condyloma acuminatum and papillary urothelial carcinomas.

Novel fusion genes in spindle cell rhabdomyosarcoma: The spectrum broadens.

Rhabdomyosarcoma (RMS) encompasses a heterogeneous group of tumors with striated muscle differentiation. RMSs are classified as alveolar, embryonal, spindle cell/sclerosing, and pleomorphic types and molecular analysis of these tumors has identified aberrations that are useful in their further subclassification. Spindle cell rhabdomyosarcoma (SpRMS) is uncommon and has been described with VGLL2 fusions, EWSR1/FUS-TFCP2 rearrangements, and myoD1 mutations-the mutations are associated with significantly different prognoses. In addition, the NCOA2-MEIS1 fusion gene was recently described in two primary intraosseous RMS that contained spindle cell components. Herein, we report three cases of SpRMS harboring different novel fusion genes, one possessing EP300-VGLL3, a second with NCOA2-MEIS1 and CAV1-MET, and the third case had HMGA2-NEGR1 and multiple amplified genes.

Prostate biopsy and radical prostatectomy Gleason score correlation in heterogenous tumors: proposal for a composite Gleason score.

When prostate biopsy cores are separately identified in multiple containers, current recommendations are to grade each specimen individually. For treatment algorithms, the highest Gleason score (HGS) is typically used as the overall score, even if a lower score predominates. This practice has the potential to misrepresent the overall cancer in the entire gland for some patients and place them in a higher-grade group. We compare a novel composite Gleason score (CGS), integrating grade patterns from contiguous positive biopsy sites, with HGS to determine correlation with the radical prostatectomy (RP) Gleason score (GS). One hundred needle biopsy cases from 2008 to 2012 with >2 GSs in a biopsy set (eg, 3+3=6, 3+4=7, and 4+3=7) or more than a 1-step difference in GS (eg, 3+4=7 and 4+4=8 without 4+3=7) were analyzed. Grades were assigned using both methods (HGS and CGS) and compared with RPGS. Grade groups I to V were used to define downgrade and upgrade. Comparing HGS with RPGS, 31% remained the same and 69% had a change in GS (87% downgraded and 13% upgraded). Comparing CGS with RPGS, 59% remained the same and 41% had a change in GS (10% downgraded and 90% upgraded). Of the 2 methods, the CGS showed better overall correlation with RP (P<0.001) and was less likely to be downgraded compared with HGS. CGS correlates better with RPGS than HGS when >2 grades are present in a biopsy set. CGS has a significantly lower rate of downgrade and predicts the RPGS more accurately than HGS.

Does discontinuous involvement of a prostatic needle biopsy core by adenocarcinoma correlate with a large tumor focus at radical prostatectomy?

When prostate needle biopsies are involved discontinuously by tumor, no consensus remains on the optimal method of tumor quantification. We investigated whether discontinuous biopsy involvement usually results from a large tumor focus or multiple small foci. Prostate needle biopsies with discontinuous tumor and corresponding whole-mounted radical prostatectomies from 2008 to 2013 were analyzed. Linear length and percentage of biopsy involvement were measured both including and subtracting the benign intervening tissue. The corresponding region of the prostatectomy specimen was evaluated for tumor size and multifocality. From over 800 biopsy sets and 400 prostatectomies performed annually, 40 patients met inclusion criteria. Excluding benign tissue, length and percentage of biopsy involvement ranged from 1 to 7 mm and 5% to 66% (median 2.5 mm, 20%), whereas including intervening tissue yielded 4 to 15.5 mm and 25% to 100%, (median 7 mm, 70%), respectively. Benign intervening tissue measured from 2 to 10.5 mm (median 3.5 mm). In 31 patients (78%), a single tumor focus was present in the corresponding region of the prostate (the dominant tumor in 25/31). In 9 patients, multiple small foci were present. Eleven patients could have been excluded from active surveillance eligibility by measuring tumor from end to end (>50% involvement), of whom only 1 met criteria for clinically insignificant cancer at prostatectomy. Discontinuous tumor in a prostate biopsy often results from a single tumor focus in the corresponding region of the prostate (78%). Therefore, we recommend that an end-to-end measurement be provided, with accompanying diagnostic comment that this often correlates with the size of a single tumor focus.