Salivary duct carcinoma with squamous differentiation: histomorphological and immunophenotypical analysis of six cases.

BACKGROUND AND AIMS: Salivary duct carcinoma (SDC) is an aggressive salivary malignancy with multiple morphological subtypes. Primary salivary squamous cell carcinoma (SCC) requires exclusion of high-grade salivary malignancies and metastatic disease and is considered exceptionally rare. We report six cases of SDC with resemblance to SCC on account of variable, but often extensive, squamous differentiation. METHODS AND RESULTS: A retrospective review (2009-2023) at two institutions of SDC with histological and immunophenotypical evidence of squamous differentiation identified six cases. Medical charts and available glass slides were reviewed. There were five males and one female with a median age of 63 years, with tumours involving the parotid (five of six) and submandibular (one of six) glands. All six tumours showed a conventional SDC component comprising < 5-90% of viable tumour. Squamous differentiation comprised 10-95%+ (> 75% in three of six cases) of total viable tumour, and demonstrated CK5/6, p63 and/or p40 immunoexpression in all cases. A sarcomatoid component, comprising 10-60% of viable tumour, was present in three of six (50%) cases. All tumours were androgen receptor (AR)-positive, but only two of six (33.3%) retained AR immunoreactivity in the squamous component. Metastatic SDC to regional lymph nodes exhibited exclusive squamous differentiation in two of six (33.3%) cases. CONCLUSION: Squamous differentiation, histologically and immunophenotypically, can be extensive in SDC. AR expression may be lost in the squamous component and metastases may demonstrate only squamous differentiation. These findings cast further doubt on the existence of primary salivary SCC. SDC should be considered whenever encountering a carcinoma with squamous differentiation in major salivary glands or within cervical lymph nodes in the setting of a salivary mass.

Salivary Ductal Carcinoma: A Case Report.

ABSTRACT: Salivary ductal carcinoma is an extremely rare tumor located in the parotid gland. This case details a salivary ductal carcinoma within the parotid gland of a 59-year-old man and its management.

Squamoid Eccrine Ductal Carcinoma: Treatment and Outcomes.

BACKGROUND: Squamoid eccrine ductal carcinoma (SEDC) represents a subtype of eccrine carcinomas that are diagnostically challenging for both clinicians and dermatopathologists. OBJECTIVE: To provide an updated review of SEDC and examine patient outcomes with different treatment modalities. METHODS: A review of Ovid MEDLINE was performed to review the English language medical literature of SEDC. RESULTS: A comprehensive review of clinical presentation, histologic findings, rates of lymphovascular and metastatic disease, treatment modalities and recurrence rates are reviewed. LIMITATIONS: There is a limitation on available data because of the rare incidence. CONCLUSIONS: SEDC is a rare adnexal neoplasm with a relatively high rate of local recurrence, lymphovascular invasion, perineural invasion, and metastases. Clinicians should be aware of this entity as close follow-up is essential to detect recurrence and metastatic disease. Mohs micrographic surgery seems to result in superior patient outcomes.

PIN-like ductal carcinoma of the prostate has frequent activating RAS/RAF mutations.

AIMS: Prostatic intraepithelial neoplasia-like (PIN-like) ductal carcinoma is a rare tumour characterised by often cystically dilated glands architecturally resembling high-grade PIN, but lacking basal cells. These tumours are frequently accompanied by grade group 1 acinar cancer and behave relatively indolently. In contrast, conventional ductal adenocarcinoma of the prostate is an aggressive variant comparable to grade group 4 acinar cancer. Here, we used targeted next-generation sequencing to molecularly profile PIN-like ductal carcinoma cases at radical prostatectomy. METHODS AND RESULTS: Five PIN-like ductal carcinoma samples at radical prostatectomy with sufficient tumour tissue available were analysed for genomic alterations by targeted next-generation sequencing using the Johns Hopkins University (JHU) solid tumour panel. DNA was captured using SureSelect for 640 genes and sequenced on the Illumina HiSeq platform. Three of five (60%) of the PIN-like ductal carcinomas showed activating mutations in the RAS/RAF pathways, which are extraordinarily rare in conventional primary prostate carcinoma (<3% of cases), including an activating hot-spot BRAF mutation (p.K601E), an activating hot-spot mutation in HRAS (p.Q61K) and an in-frame activating deletion in BRAF (p.T488_Q493delinsK). An additional two cases lacked BRAF or HRAS mutations, but harboured in-frame insertions of uncertain significance in MAP2K4 and MAP3K6. One case had sufficient acinar tumour for sequencing, and showed a similar molecular profile as the concurrent PIN-like ductal carcinoma, suggesting a clonal relationship between the two components. CONCLUSIONS: PIN-like ductal carcinoma represents a molecularly unique tumour, enriched for potentially targetable oncogenic driver mutations in the RAS/RAF/MAPK pathway. This molecular profile contrasts with that of conventional ductal adenocarcinoma, which is typically enriched for pathogenic mutations in the mismatch repair (MMR) and homologous recombination (HR) DNA repair pathways.

Oncocytic intraductal carcinoma of salivary glands: a distinct variant with TRIM33-RET fusions and BRAF V600E mutations.

AIMS: Salivary gland intraductal carcinoma (IDC) is a complex ductal neoplasm surrounded by a layer of myoepithelial cells. Recent insights have shown that there are three different types: intercalated duct-like, with frequent NCOA4-RET fusions; apocrine, with salivary duct carcinoma-like mutations; and mixed intercalated duct-like/apocrine, with RET fusions, including TRIM27-RET. In addition, an oncocytic IDC has been described, but it remains unclear whether it represents a fourth variant or simply oncocytic metaplasia of another IDC type. Our aim was to more completely characterize oncocytic IDC. METHODS AND RESULTS: Six IDCs with oncocytic changes were retrieved from the authors' archives, from three men and three women ranging in age from 45 to 75 years (mean, 63 years). Five arose in the parotid gland, with one in an accessory parotid gland. Four patients with follow-up were free of disease after 1-23 months. Several immunostains (S100, mammaglobin, androgen receptor, and p63/p40) and molecular tools (RNA sequencing, RET fluorescence in-situ hybridisation, BRAF V600E VE1 immunohistochemistry, and Sanger sequencing) were applied. Histologically, the tumours were variably cystic with solid intracystic nodules often difficult to recognise as intraductal. In all, tumour ducts were positive for S100 and mammaglobin, negative for androgen receptor, and completely surrounded by myoepithelial cells positive for p63/p40. Molecular analysis revealed TRIM33-RET in two of six cases, NCOA4-RET in one of six cases, and BRAF V600E in two of six cases. One case had no identifiable alterations. CONCLUSIONS: Oncocytic IDC shares similarities with intercalated duct-like IDC. Although additional verification is needed, the oncocytic variant appears to be sufficiently unique to be now regarded as the fourth distinct subtype of IDC. Because of its indolent nature, oncocytic IDC should be distinguished from histological mimics.

The significance of tyrosine kinase receptor B and brain-derived neurotrophic factor expression in salivary duct carcinoma.

Salivary duct carcinoma (SDC) is a high-grade salivary gland neoplasm. It may occur de novo or secondarily from pleomorphic adenoma (ex-PA), with secondary development accounting for more than 50% of the cases. In recent years, the expression of tyrosine kinase receptor B (TrkB), which is in the same family as HER2, has been confirmed in various types of carcinomas. However, there are a few studies on SDC. In order to examine the expression and role of TrkB in SDC, we investigated it. Immunohistochemistry was used to detect the expression of TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) in 20 patients with SDC. The mRNA levels of TrkB, BDNF, and NT-4 were analyzed using quantitative polymerase chain reaction. TrkB was negative in 10 cases and positive in 10 cases, BDNF was negative in 11 cases and positive in 9 cases, and NT-4 was positive in all cases. There was a high number of TrkB-positive cases in the pT4 group and The H-score of TrkB was also significantly higher in the stage III and IV groups. There was a high number of BDNF-positive cases in the ex-PA group and Histo-score of BDNF had a trend of high expression in ex-PA. There were no significant differences or correlations in mRNA expression. Our results suggest that TrkB may be involved in SDC tumor growth.

Primary De novo ductal adenocarcinoma of the lacrimal gland.

BACKGROUND: Primary ductal adenocarcinoma of the lacrimal gland is a rare and aggressive malignant epithelial lacrimal gland neoplasm, morphologically and phenotypically resembles salivary duct carcinoma, and both strongly resemble infiltrating ductal carcinoma of breast. METHOD: Retrospective Chart review of cases of malignant lacrimal gland tumors from 2013 July to 2020 July. Authors describe the clinico radiological, morphological and immunohistochemical features of primary ductal adenocarcinoma (PDA) of lacrimal gland. Extensive review of literature of PDA of lacrimal gland and salivary gland ductal carcinoma has been performed. RESULTS: Retrospective chart review of the last 7 years yielded 22 malignant lacrimal gland neoplasms of which 4 cases demonstrated features of primary ductal adenocarcinoma of lacrimal gland, 2/4 cases showed an evidence of a pre existing pleomorphic adenoma and 2 were found to be de novo ductal adenocarcinomas. PDA of lacrimal gland showed expression of CK7, CK19, AR, HER2, cyclin D1 and were negative for CK5/14, CK 20, ER, PR, PSA, TTF-1, S-100 and SMA. Expression of GCDFP-15 was noted in one case. The presence of multiple events of loco-regional recurrences and/or distant metastasis necessitated a multidisciplinary approach. CONCLUSIONS: Authors have expressed the need of clinical correlation; thorough tissue sampling and extensive immunohistochemical work up in identification of de novo PDA's and their molecular subtypes. A multi-institutional study might help in formulating the diagnostic criteria, identification of actionable targets, and thus study the role of targeted therapy in this rare and aggressive tumor which may result in better patient outcomes.

Patterns of metastases of prostatic ductal adenocarcinoma.

BACKGROUND: The current study was conducted to investigate the patterns of metastases in men with metastatic prostatic ductal adenocarcinoma (DAC) and recurrence patterns after therapy. METHODS: All patients with a new diagnosis of DAC with de novo metastases and those with localized disease who developed metastases after treatment and were treated at the study institution from January 2005 to November 2018 were included. All patient and tumor characteristics and outcome data were collected. RESULTS: A total of 164 patients (37.7%) had metastatic DAC, including 112 with de novo metastases and 52 who developed metastases after treatment. Men with de novo metastases were found to have a significantly higher median prostate-specific antigen level and International Society of Urological Pathology grade but a lower cT3 and/or T4 classification compared with those with metastases that developed after treatment (all P < .05). Approximately 87% of men with de novo metastases progressed despite multiple systemic therapies, 37.6% required intervention for the palliation of symptoms, and 10.1% responded to systemic therapy and underwent treatment of the primary tumor. Men with de novo metastatic DAC and those who developed metastases after treatment had multiple metastatic sites (including bone and viscera), with higher rates of lung metastases noted in the posttreatment group (23.2% vs 44.2%; P = .01). A total of 45 patients who were treated with curative intent developed metastases at a median of 22 months (range, 0.9-74.8 months) after treatment, at low prostate-specific antigen levels (median, 4.4 ng/mL [interquartile range, 1.7-11.1 ng/mL]). CONCLUSIONS: The current study described the metastatic patterns of DAC in both patients with de novo metastatic disease and those who later progress to metastases. Men receiving treatment for DAC with curative intent require stringent long-term follow-up with imaging modalities, including chest imaging given the predilection toward lung metastases noted among these patients.

Elastin and collagen IV double staining: A refined method to detect blood vessel invasion in breast cancer.

Blood vessel invasion (BVI) is a prognostic indicator in various cancers. Elastic stain, which highlights blood vessel walls, is commonly used to detect BVI. In the breast, however, its diagnostic usefulness is limited because it also highlights some intraductal carcinoma components, which often mimic BVI. In this study, we aimed to improve BVI detection in breast cancer and developed a double staining: Victoria blue for elastin and immunohistochemistry for collagen IV. Collagen IV fibers were retained along the basement membranes of intraductal carcinoma components, whereas they were rearranged or lost in BVI. From these observations, we defined BVI as the presence of tumor cells inside an elastic ring with a rearrangement or loss of collagen IV fibers. Using these criteria, we found BVI in 148 cases (49%) among 304 cases of primary operable invasive breast carcinoma, and the presence of BVI correlated significantly with poor prognosis. By contrast, we detected BVI in 94 cases (31%) or 14 cases (5%) by elastic van Gieson or CD31 immunostaining among the same cases, respectively, with no statistically significant association with prognosis. Thus, elastin and collagen IV double staining facilitates the detection of BVI in breast cancer and is useful to predict prognosis.

Histologic diagnosis of a case of anal duct carcinoma with cytological correlation and differential diagnoses.

Anal duct carcinoma is an uncommon malignancy of the glands of the anal duct. This entity poses a diagnostic challenge, both clinically and histologically. This article describes histopathologic findings in a case of anal duct carcinoma, including the initial diagnosis on biopsy and subsequent cytology specimens. Additionally, differential diagnoses of this neoplasm are discussed. With a high index of suspicion, and attention to histological and immunohistochemical features, anal duct carcinoma can be accurately diagnosed both on biopsy and on cytology.

Concordance of biopsy and prostatectomy diagnosis of intraductal and cribriform carcinoma in a prospectively collected data set.

AIMS: Intraductal and cribriform carcinoma of the prostate are increasingly recognised as independent prognosticators of poor outcome, both in prostate biopsies and surgical specimens. We studied the concordance of biopsy and prostatectomy diagnosis for these two subpathologies in relationship with pathological stage. METHODS AND RESULTS: Mandatory synoptic reporting of intraductal and cribriform carcinoma in prostate biopsies and prostatectomy specimens was adopted by two academic institutions in November 2015. Synoptic reports of 245 biopsy and corresponding prostatectomy specimens were interrogated to determine the prevalence of intraductal and cribriform carcinoma. Sensitivity and specificity were determined, with prostatectomy diagnosis as the gold standard. Associations with pathological stage as primary outcome parameter were determined using univariable and multivariable logistic regression analysis. Prevalence of the combination of intraductal and cribriform carcinoma was 26.9% in biopsies and 51.8% in prostatectomy specimens. Sensitivity and specificity at biopsy were 47.2% and 94.9%, respectively. Intraductal and cribriform carcinoma at biopsy were associated with advanced pathological stage independent of grade (P = 0.013). Among patients with grade group 2 prostate cancer at biopsy, the more advanced pathological stage distribution was similar for those with a false negative and a true positive biopsy diagnosis of intraductal and cribriform carcinoma (P = 0.29). CONCLUSION: In spite of low sensitivity, intraductal and cribriform carcinoma at biopsy was associated strongly with advanced stage at radical prostatectomy. As a false negative biopsy diagnosis was equally associated with advanced pathological stage, efforts should be undertaken to improve the sensitivity of biopsy diagnosis for intraductal and cribriform carcinoma.

Apparent diffusion coefficient cannot predict molecular subtype and lymph node metastases in invasive breast cancer: a multicenter analysis.

BACKGROUND: Radiological imaging plays a central role in the diagnosis of breast cancer (BC). Some studies suggest MRI techniques like diffusion weighted imaging (DWI) may provide further prognostic value by discriminating between tumors with different biologic characteristics including receptor status and molecular subtype. However, there is much contradictory reported data regarding such associations in the literature. The purpose of the present study was to provide evident data regarding relationships between quantitative apparent diffusion coefficient (ADC) values on DWI and pathologic prognostic factors in BC. METHODS: Data from 5 centers (661 female patients, mean age, 51.4 ± 10.5 years) were acquired. Invasive ductal carcinoma (IDC) was diagnosed in 625 patients (94.6%) and invasive lobular carcinoma in 36 cases (5.4%). Luminal A carcinomas were diagnosed in 177 patients (28.0%), luminal B carcinomas in 279 patients (44.1%), HER 2+ carcinomas in 66 cases (10.4%), and triple negative carcinomas in 111 patients (17.5%). The identified lesions were staged as T1 in 51.3%, T2 in 43.0%, T3 in 4.2%, and as T4 in 1.5% of the cases. N0 was found in 61.3%, N1 in 33.1%, N2 in 2.9%, and N3 in 2.7%. ADC values between different groups were compared using the Mann-Whitney U test and by the Kruskal-Wallis H test. The association between ADC and Ki 67 values was calculated by Spearman's rank correlation coefficient. RESULTS: ADC values of different tumor subtypes overlapped significantly. Luminal B carcinomas had statistically significant lower ADC values compared with luminal A (p = 0.003) and HER 2+ (p = 0.007) lesions. No significant differences of ADC values were observed between luminal A, HER 2+ and triple negative tumors. There were no statistically significant differences of ADC values between different T or N stages of the tumors. Weak statistically significant correlation between ADC and Ki 67 was observed in luminal B carcinoma (r = - 0.130, p = 0.03). In luminal A, HER 2+ and triple negative tumors there were no significant correlations between ADC and Ki 67. CONCLUSION: ADC was not able to discriminate molecular subtypes of BC, and cannot be used as a surrogate marker for disease stage or proliferation activity.

Prognostic Values of CD38+CD101+PD1+CD8+ T Cells in Pancreatic Cancer.

Programmed death-1 (PD-1), a key immune checkpoint molecule, has been developed as an oncotherapy target for various carcinomas. However, treatment with anti-PD-1 elicited only a minimal effect in pancreatic ductal adenocarcinoma (PDAC). Subsequent studies revealed the existence of a subset of PD-1+ T cells coexpressing CD38 and CD101, representing a fixed dysfunctional subpopulation that are not able to be rescued by anti-PD-1 immunotherapy. However, whether this subpopulation of PD-1 expressing CD8+ T cells could be useful in predicting PDAC stage or prognosing survival is unknown. In this study, we used flow cytometry and immunofluorescence assay to analyze the expression of CD38 and CD101 in 183 clinical PDAC samples, including 84 of peripheral blood and 99 of surgical tissues. High coexpression of CD38/CD101 on peripheral PD-1+CD8+ T cells or tumor-infiltrating lymphocytes (TILs) was found to be most significantly correlated with Tumor/Node/Metastasis (T/N/M) classification and clinical stage, in contrast PD-1+CD8+ T cells could not correlate with T classification. CD38/CD101 co-repression on TILs also correlated with the poor survival in these PDAC patient samples. Our data suggest that CD38/CD101 might represent a more helpful biomarker than PD-1 alone for diagnosis and prognosis of PDAC.

Squamoid Eccrine Ductal Carcinoma: An Aggressive Mimicker of Squamous Cell Carcinoma.

Squamoid eccrine ductal carcinoma (SEDC) is an uncommon cutaneous adnexal malignancy that has the potential for an aggressive clinical course. The authors present a case of SEDC that resulted in widespread metastases and death. The clinical, histological, and immunohistochemical features of SEDC and several entities on the differential diagnosis are reviewed.

Adenomatous ductal proliferation/hyperplasia in the parotid gland associated without any other pathological lesions; a report and survey of the literatures.

Adenomatous ductal proliferation/hyperplasia (ADP/H) is a rare hyperplastic condition of the salivary gland. It is mostly associated with other salivary gland pathologies such as tumors and inflammations, and is incidentally found in tissue sections during histopathological examinations of those diseases. Herein, we report a case of ADP/H in the parotid gland not associated with any other pathological lesions, and present a review of the literature on this condition. A 60-year-old Japanese female complained of swelling on the left side of parotid region. Clinical examination revealed a swelling on the lower lobe of the left parotid gland. The lesion was firm but non-tender and was not attached to adjacent structures. A clinical diagnosis of benign salivary gland tumor was reached, and surgical excision was performed under general anesthesia. Histopathological examination revealed an intact parotid gland capsule with isomorphic and basaloid cells within scanty cytoplasm. In addition, an admixture of hyperplasia and proliferation of the intercalated ducts, the presence of zymogen granules, the absence of solid nests, and a peripheral palisaded arrangement of the cells were observed. Based on these findings, a diagnosis of ADP/H was confirmed. ADP/H is a non-tumorous lesion; therefore, tumor involvement should be ruled out before the diagnosis is reached.

Case Report: Intraductal Papillary Mucinous Neoplasms of the Biliary Tract.

The present case report describes intraductal papillary mucinous neoplasms of the biliary tract (IPMN-BT), a rare neoplasm of the biliary tract that is described as the biliary counterpart of intraductal papillary mucinous neoplasms of the pancreas (IPMN-P). The importance of appropriate diagnosis and awareness of the clinical manifestations is highlighted. IPMN-BT has a more favorable prognosis and is easier to resect than other forms of intrahepatic cholangiocarcinomas; therefore, early and accurate diagnosis is required for planning of the best treatment strategies for this neoplasm.

Ductal adenocarcinoma of the prostate: Clinical and biological profiles.

BACKGROUND: Ductal adenocarcinoma (DAC) is a rare and aggressive subtype of prostate cancer (PCa). In the present study, we analyzed the clinical and biological characteristics of DAC, in comparison with high grade conventional acinar PCa. METHODS: Samples and data were retrospectively collected from seven institutions and centrally reviewed. Immunohistochemistry was performed on tissue microarrays to assess the expression of candidate proteins, based on the molecular classification of PCa, including ERG, PTEN, and SPINK1. SPOP mutations were investigated from tumor DNA by Sanger sequencing. Relationships with outcome were analyzed using log-rank analysis and multivariable Cox regression. RESULTS: Among 56 reviewed prostatectomy specimens, 45 cases of DAC were finally confirmed. The pathological stage was pT3 in more than 66% of cases. ERG was expressed in 42% of DAC, SPINK1 in 9% (all ERG-negative), and two cases (ERG-negative) harbored a SPOP mutation. Compared to high grade conventional PCa matched for the pathological stage, cell proliferation was higher (P = 0.04) in DAC, and complete PTEN loss more frequent (P = 0.023). In multivariate analysis, SPINK1 overexpression (P = 0.017) and loss of PSA immunostaining (P = 0.02) were significantly associated with biochemical recurrence. CONCLUSION: these results suggest that, despite biological differences that highlighted DAC aggressiveness, the molecular classification recently proposed in conventional PCa could also be applied in DAC.

Specimen Identification Errors in Breast Biopsies: Age Matters. Report of Two Near-Miss Events and Review of the Literature.

The consequences of patient identification errors due to specimen mislabeling can be deleterious. We describe two near-miss events involving mislabeled breast specimens from two patients who sought treatment at our institution. In both cases, microscopic review of the slides identified inconsistencies between the histologic findings and patient age, unveiling specimen identification errors. By correlating the clinical information with the microscopic findings, we identified mistakes that had occurred at the time of specimen accessioning at the original laboratories. In both cases, thanks to a timely reassignment of the specimens, the patients suffered no harm. These cases highlight the importance of routine clinical and pathologic correlation as a critical component of quality assurance and patient safety. A review of possible specimen identification errors in the anatomic pathology setting is presented.

Biopsy undergrading in men with Gleason score 6 and fatal prostate cancer in the European Randomized study of Screening for Prostate Cancer Rotterdam.

OBJECTIVES: A total of 15 men who died of prostate cancer had cT1/2 biopsy Gleason score ≤6 prostate cancer at prevalence screening in the European Randomized study of Screening for Prostate Cancer Rotterdam. Our objective was to explain (part of) these prostate cancer deaths by undergrading with the classical Gleason score. METHODS: Biopsy specimens of 98 men with classical Gleason score ≤6 or 3 + 4 = 7 at prevalence screening in the European Randomized study of Screening for Prostate Cancer Rotterdam were retrospectively reviewed by two pathologists using the International Society of Urological Pathology 2014 modified Gleason score. These 98 men included 15 men with cT1/2 classical Gleason score ≤6 who died of prostate cancer (cases) and 83 randomly selected men with classical Gleason score ≤6 or 3 + 4 = 7 (controls). The primary outcome was the reclassification rate from classical Gleason score ≤6 to modified classical Gleason score 3 + 4 = 7 (grade group 2) stratified for prostate cancer death. The secondary outcome was the rate of cribriform/intraductal carcinoma in Gleason score-reclassified men stratified for prostate cancer death. RESULTS: A total of 79 out of 98 men had classical Gleason score ≤6 prostate cancer. A total of eight out of 15 (53%) prostate cancer deaths with classical Gleason score ≤6 were reclassified to modified Gleason score 3 + 4 = 7, compared with 16 out of 64 (25%) men with non-fatal prostate cancer (P = 0.017). A total of five out of eight (63%) Gleason score-reclassified men with fatal prostate cancer had cribriform/intraductal carcinoma, compared with two out of 16 (13%) Gleason score-reclassified men with non-fatal prostate cancer (P = 0.011). CONCLUSIONS: Part of the prostate cancer deaths with Gleason score ≤6 at prevalence screening in the European Randomized study of Screening for Prostate Cancer Rotterdam could be explained by biopsy undergrading. The present study confirms that the International Society of Urological Pathology 2014 modified Gleason score is more accurate for prognostic assessment based on prostate biopsy than the classical Gleason score.

Subsets of salivary duct carcinoma defined by morphologic evidence of pleomorphic adenoma, PLAG1 or HMGA2 rearrangements, and common genetic alterations.

BACKGROUND: The authors hypothesized that histogenetic classification of salivary duct carcinoma (SDC) could account for de novo tumors and those with morphologic or molecular evidence (pleomorphic adenoma gene 1 [PLAG1], high-mobility group AT hook 2 [HMGA2] rearrangement, amplification) of pleomorphic adenoma (PA). METHODS: SDCs (n = 66) were reviewed for morphologic evidence of PA. PLAG1 and HMGA2 alterations were detected by fluorescence in situ hybridization (FISH). PLAG1-positive tumors were tested by FISH for fibroblast growth factor receptor 1 (FGFR1) rearrangement. Thirty-nine tumors were analyzed using a commercial panel for mutations and copy number variations in 50 cancer-related genes. RESULTS: On the basis of combined morphologic and molecular evidence of PA, 4 subsets of SDC emerged: 1) carcinomas with morphologic evidence of PA but intact PLAG1 and HMGA2 (n = 22); 2) carcinomas with PLAG1 alteration (n = 18) or 3) HMGA2 alteration (n = 12); and 4) de novo carcinomas, without morphologic or molecular evidence of PA (n = 14). The median disease-free survival was 37 months (95% confidence interval, 28.4-45.6 months). Disease-free survival and other clinicopathologic parameters did not differ for the subsets defined above. Combined Harvey rat sarcoma viral oncogene homolog/phosphatidylinositol-4,5-biphosphate 3-kinase, catalytic subunit α (HRAS/PIK3CA) mutations were observed predominantly in de novo carcinomas (5 of 8 vs 2 of 31 tumors; P = .035). Erb-B2 receptor tyrosine kinase 2 (ERBB2) copy number gain was not observed in de novo carcinomas (0 of 8 vs 12 of 31 tumors; P = .08). Tumor protein 53 (TP53) mutations were more common in SDC ex pleomorphic adenomas than in de novo carcinomas (17 of 31 vs 1 of 8 tumors; P = .033). CONCLUSIONS: The genetic profile of SDC varies with the absence or presence of pre-existing PA and its cytogenetic signature. Most de novo SDCs harbor combined HRAS/PIK3CA mutations and no ERBB2 amplification. Cancer 2016;122:3136-44. © 2016 American Cancer Society.