Epithelioid angiomyolipoma: a pathological entity discovered in Verona with the endorsement of Doctor Rosai.

In this manuscript, we summarize the main features of angiomyolipoma highlighting the recognition of epithelioid angiomyolipoma and the discovery of immunohistochemical expression of HMB45 in a group of tumors that now are referred to as as PEComas. In this scenario, Dr. Rosai believed in our intuition, demonstrating his intellectual honesty and motivated us with his experience ("when a tumor seems malignant it is malignant") and enthusiasm for the new entities ("in Verona, you use HMB45 instead of H&E"). He really pushed the improvement of the knowledge in this field.

Angiomyolipoma of the kidney: from simple hamartoma to complex tumour.

Angiomyolipoma is the most common mesenchymal tumour of the kidney, even if for a long time it has been viewed as a hamartoma rather than a neoplasm. It belongs to a family of neoplasms, named PEComa, characterised by the constant presence of perivascular epithelioid cells that co-express smooth muscle and melanogenesis markers. Angiomyolipoma can occur in patients with tuberous sclerosis, a hereditary syndrome due to the alteration of TSC1 or TSC2 genes, or sporadically. Angiomyolipoma and its variants are indolent tumours; however, some epithelioid angiomyolipomas/pure epithelioid PEComas are aggressive, and criteria for malignancy have been proposed to identify those cases. Although typical angiomyolipoma is a straightforward diagnosis, pathologists should be aware of the wide morphological spectrum of its variants which could be tricky in routine clinical practice and could require immunohistochemical analysis for resolution. The differential diagnosis may range from an inflammatory process (for instance xanthogranulomatous pyelonephritis) to the most common renal cancers and sarcomas. The immunoexpression of melanogenesis markers (HMB45 and Melan-A) and cathepsin K is extremely helpful in the majority of cases. Recently, a subset of epithelioid angiomyolipoma/pure epithelioid PEComa harbouring TFE3 gene fusions has been described, raising questions about its relationship with the family of perivascular epithelioid cell tumour. The activation of the mTOR pathway due to genetic alterations of tuberous sclerosis complex in TSC1 or TSC2 genes in angiomyolipoma has also been reported as well as the subsequent therapeutic implications.

Subpopulation Treatment Effect Pattern Plot (STEPP) analysis of Ki67 assay according to histology: prognostic relevance for resected early stage 'pure' and 'mixed' lobular breast cancer.

BACKGROUND: The aim of this analysis was to investigate the potential impact of Ki67 assay in a series of patients affected by early stage invasive lobular carcinoma (ILC) undergone surgery. METHODS: Clinical-pathological data were correlated with disease-free and overall survival (DFS/OS). The maximally selected Log-Rank statistics analysis was applied to the Ki67 continuous variable to estimate appropriate cut-offs. The Subpopulation Treatment Effect Pattern Plot (STEPP) analysis was performed to assess the interaction between 'pure' or 'mixed' histology ILC and Ki67. RESULTS: At a median follow-up of 67 months, 10-years DFS and OS of 405 patients were 67.8 and 79.8%, respectively. Standardized Log-Rank statistics identified 2 optimal cut-offs (6 and 21%); 10-years DFS and OS were 75.1, 66.5, and 30.2% (p = 0.01) and 84.3, 76.4 and 59% (p = 0.003), for patients with a Ki67 < 6%, between 6 and 21%, and >21%, respectively. Ki67 and lymph-node status were independent predictor for longer DFS and OS at the multivariate analysis, with radiotherapy (for DFS) and age (for OS). Ki67 highly replicated at the internal cross-validation analysis (DFS 85%, OS 100%). The STEPP analysis showed that DFS rate decreases as Ki67 increases and those patients with 'pure' ILC performed worse than 'mixed' histology. CONCLUSIONS: Despite the retrospective and exploratory nature of the study, Ki67 was able to significantly discriminate the prognosis of patients with ILC, and the effect was more pronounced for patients with 'pure' ILC.

Ultrasound-guided percutaneous fine-needle aspiration of solid pancreatic neoplasms: 10-year experience with more than 2,000 cases and a review of the literature.

OBJECTIVES: To evaluate the diagnostic accuracy and complication rate of percutaneous ultrasound-guided fine-needle aspiration (US-FNA) of solid pancreatic neoplasms through the analysis of 10-year experiences of two centres. METHODS: Clinical, radiological and pathologic data of 2,024 patients with solid pancreatic masses who underwent US-FNAs were retrospectively evaluated. Indications for aspiration were: unresectable lesions before neo-adjuvant therapy; doubtful imaging findings; and suspicion of uncommon neoplasms with prognostic or therapeutic implications such as metastases or lymphoma. US-FNAs were performed using aspiration needles with a cytopathologist present in centre 1. In centre 2, cytologic samples were collected with Chiba needles and separately evaluated by a cytopathologist. RESULTS: US-FNA had a diagnostic sample rate of 92.2 % (centre 1: 95.9 %; centre 2: 87.2 %). US-FNA repetition after non-diagnostic samples provided a diagnosis in 86.3 % of cases. Sensitivity, specificity, positive and negative predictive values, and accuracy were 98.7 %, 100 %, 100 %, 75.5 %, and 98.7 %, respectively. The complication rate was 0.8 %. CONCLUSIONS: Percutaneous US-FNA is a sensitive, accurate and safe method for the invasive diagnosis of solid pancreatic neoplasms. The use of aspiration needles and the on-site presence of a cytopathologist may lead to a high rate of diagnostic samples, thus reducing the need for US-FNA repetition. KEY POINTS: • Percutaneous ultrasound-guided fine-needle aspiration of pancreatic neoplasms is sensitive and accurate. • The short-term complication rate of percutaneous ultrasound-guided fine-needle aspiration is low. • Technical aspects may influence the rate of diagnostic samples.

Monosomy of chromosome 17 in breast cancer during interpretation of HER2 gene amplification.

Monosomy of chromosome 17 may affect the assessment of HER2 amplification. Notably, the prevalence ranges from 1% up to 49% due to lack of consensus in recognition. We sought to investigate the impact of monosomy of chromosome 17 to interpretation of HER2 gene status. 201 breast carcinoma were reviewed for HER2 gene amplification and chromosome 17 status. FISH analysis was performed by using double probes (LSI/CEP). Absolute gene copy number was also scored per each probe. HER2 FISH test was repeated on serial tissue sections, ranging in thickness from 3 to 20 µm. Ratio was scored and subsequently corrected by monosomy after gold control test using the aCGH method to overcome false interpretation due to artefactual nuclear truncation. HER2 immunotests was performed on all cases. 26/201 cases were amplified (13%). Single signals per CEP17 were revealed in 7/201 (3.5%) cases. Five out of 7 cases appeared monosomic with aCGH (overall, 5/201, 2.5%) and evidenced single signals in >60% of nuclei after second-look on FISH when matching both techniques. Among 5, one case showed amplification with a pattern 7/1 (HER2/CEP17>2) of copies (3+ at immunotest); three cases revealed single signals per both probes (LSI/CEP=1) and one case revealed a 3:1 ratio; all last 4 cases showed 0/1+ immunoscore. We concluded that: 1) monosomy of chromosome 17 may be observed in 2.5% of breast carcinoma; 2) monosomy of chromosome 17 due to biological reasons rather than nuclear truncation was observed when using the cut-off of 60% of nuclei harboring single signals; 3) the skewing of the ratio due to single centromeric 17 probe may lead to false positive evaluation; 4) breast carcinomas showing a 3:1 ratio (HER2/CEP17) usually show negative 0/1+ immunoscore and <6 gene copy number at FISH.

Systems biology analysis reveals NFAT5 as a novel biomarker and master regulator of inflammatory breast cancer.

BACKGROUND: Inflammatory breast cancer (IBC) is the most rare and aggressive variant of breast cancer (BC); however, only a limited number of specific gene signatures with low generalization abilities are available and few reliable biomarkers are helpful to improve IBC classification into a molecularly distinct phenotype. We applied a network-based strategy to gain insight into master regulators (MRs) linked to IBC pathogenesis. METHODS: In-silico modeling and Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) on IBC/non-IBC (nIBC) gene expression data (n = 197) was employed to identify novel master regulators connected to the IBC phenotype. Pathway enrichment analysis was used to characterize predicted targets of candidate genes. The expression pattern of the most significant MRs was then evaluated by immunohistochemistry (IHC) in two independent cohorts of IBCs (n = 39) and nIBCs (n = 82) and normal breast tissues (n = 15) spotted on tissue microarrays. The staining pattern of non-neoplastic mammary epithelial cells was used as a normal control. RESULTS: Using in-silico modeling of network-based strategy, we identified three top enriched MRs (NFAT5, CTNNB1 or ß-catenin, and MGA) strongly linked to the IBC phenotype. By IHC assays, we found that IBC patients displayed a higher number of NFAT5-positive cases than nIBC (69.2% vs. 19.5%; p-value = 2.79 10(-7)). Accordingly, the majority of NFAT5-positive IBC samples revealed an aberrant nuclear expression in comparison with nIBC samples (70% vs. 12.5%; p-value = 0.000797). NFAT5 nuclear accumulation occurs regardless of WNT/ß-catenin activated signaling in a substantial portion of IBCs, suggesting that NFAT5 pathway activation may have a relevant role in IBC pathogenesis. Accordingly, cytoplasmic NFAT5 and membranous ß-catenin expression were preferentially linked to nIBC, accounting for the better prognosis of this phenotype. CONCLUSIONS: We provide evidence that NFAT-signaling pathway activation could help to identify aggressive forms of BC and potentially be a guide to assignment of phenotype-specific therapeutic agents. The NFAT5 transcription factor might be developed into routine clinical practice as a putative biomarker of IBC phenotype.

PEComas of the kidney and of the genitourinary tract.

PEComas are mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells that are characterized by the coexpression of muscle and melanogenetic markers. This group of lesions includes angiomyolipoma, clear cell "sugar" tumor of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, and rare clear cell tumors of other anatomical sites. In the genitourinary tract, PEComas have been described in the kidney, bladder, prostate, testis, and urethra. Although most PEComas behave as benign tumors, some are potentially malignant, and criteria for malignancy have been suggested for both and renal and extrarenal lesions. Recently, the expression of cathepsin K has been demonstrated in a large number of PEComas and has been proposed as a relatively specific marker to distinguish these proliferations from the majority of human cancers. In addition, a distinctive subset of PEComas harboring TFE3 gene fusions has been reported, giving rise to a possible relationship between them and MiTF/TFE family translocation renal cell carcinomas. The genetic alterations of tuberous sclerosis complex that promote activation of the mTOR pathway have been identified in PEComas. Therapy with mTORC1 inhibitors has been shown to be effective in some cases.

Human epidermal growth factor receptor 2-positive breast cancer: heat shock protein 90 overexpression, Ki67 proliferative index, and topoisomerase II-α co-amplification as predictors of pathologic complete response to neoadjuvant chemotherapy with trastuzumab and docetaxel.

BACKGROUND: The combination of trastuzumab and chemotherapy is currently considered the standard of care for patients with locally advanced/operable human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The potential correlation between the pathologic complete response (pCR) and the overexpression of heat shock protein 90 (Hsp90), Ki67, and the amplification of topoisomerase II-α (TOPO2A) was investigated in a series of patients who received neoadjuvant treatment. METHODS: HER2-amplified patients who received neoadjuvant trastuzumab-docetaxel were gathered. Baseline and postsurgical Hsp90 immunoscore, Ki67 proliferation index, and TOPO2A amplification were determined together with classic clinical-pathologic predictors and correlated with pCR and imaging data. RESULTS: A total of 24 patients were evaluated for response; pCR, clinical, and radiologic response were found in 4 patients (16.7%; 95% confidence interval [CI], 1.7-31.5), 9 patients (37.5%; 95% CI, 18.1-56.8), and 6 patients (25.0%; 95% CI, 7.6-42.3) patients, respectively. pCR was significantly higher in premenopausal (60.0% vs. 5.3%, P = .02) and negative hormonal receptor patients (50.0% vs. 5.6%, P = .03). A trend for patients with high Ki67 and TOPO2A/HER2 co-amplification was found (21.1% vs. none, P = .54; 50.0% vs. 12%, P = .16). pCR was significantly higher in patients with Hsp90 score 3+, in comparison with score 2+ and score 1+ (50.0% vs. 14.3% vs. none, P = .05). After treatment, a statistically significant lower Ki67 staining (30.0% vs. 17.5%, P = .005) and a trend for the decreased expression of high (score 3+) and moderate (score 2+) Hsp90 immunostaining (McNemar P = .25, Wilcoxon-Mann-Whitney P = .08) were found. CONCLUSIONS: Although underpowered, our data suggest that patients with HER2-positive breast cancer overexpressing Hsp90 should be investigated as a "newer" molecular subtype with a significantly higher chance of pCR when receiving anti-Her2 agents.

Comparison between invasive breast cancer with extensive peritumoral vascular invasion and inflammatory breast carcinoma: a clinicopathologic study of 161 cases.

OBJECTIVES: Extensive peritumoral neoplastic lymphovascular invasion (ePVI) is a marker of aggressiveness in invasive breast carcinoma (BC). METHODS: We explored the impact of ePVI on different BC subtypes. In a total of 2,116 BCs, 91 ePVI-BCs, 70 inflammatory breast carcinomas (IBCs), and 114 casual BCs as a control group (CG-BC) were recruited. RESULTS: Patients affected by ePVI-BC were younger, had larger tumors, higher histologic grade, elevated Ki-67 score, Her2/neu overexpressed, and more lymph node metastases compared with CG-BC (P < .001). Interestingly, only younger mean age at diagnosis differentiated patients with ePVI-BC from patients affected by IBC. ePVI-BC showed a clinical outcome intermediate between the prognoses of IBC and CG-BC. CONCLUSIONS: Results suggest that ePVI-BC and IBC may share some pathologic processes, providing a novel perspective on the heterogeneity of BC. Epidemiologic data and molecular studies on gene expression features are needed to rationally classify these tumors into their identified subtypes.

HER2/neu gene determination in women screened for breast carcinoma: how screening programs reduce the skyrocketing cost of targeted therapy.

Few data on Human Epidermal Growth Factor Receptor 2 (HER2)-positive breast carcinomas have been reported for screen-detected breast carcinoma. Assessing the impact of a targeted intervention with anti-HER2 inhibitors on costs is required in order to plan for better strategies in screening programs. A total of 54,472 women were screened and 323 cases were found to be invasive cancer. We performed immunophenotypical-fluorescent in situ hybridization (FISH) analysis. Among 153 evaluable breast carcinomas, tumours displayed a 3+ scoring status 3+ in 16 (10%), 2+ in 12 (8%), 1+ in 29 (19%) and 0 in 96 (63%) of cases, respectively. All 3+ HER2+ cases and 2/12 2+ (17%) cases exhibited HER2/neu gene amplification, the remaining cases did not. In contrast to the higher incidence reported at the population level, 20-30% HER2-positive cases for metastatic carcinomas, and only 11% of the screen-detected breast carcinomas displayed HER2/neu gene amplification. Breast cancer detection by screening programs hijacks the skyrocketing cost of the use of targeted therapy in HER2-positive carcinoma.

The identification of a small but significant subset of patients still targetable with anti-HER2 inhibitors when affected by triple negative breast carcinoma.

PURPOSE: Triple (ER-, PR-, HER2-) negative breast carcinoma lack targeted therapies, making this group of tumors difficult to treat. By definition, the lack of HER2 expression means a case scoring 0 or 1+ after immunophenotypical analysis and makes the patients avoiding therapeutical chances with anti-HER2 inhibitors. We sought to recruit from a group of triple negative breast carcinoma, patients eligible for effective personalized targeted therapy with anti-HER therapies on the basis of their HER2 gene status. METHODS: 135 patients diagnosed with IHC triple negative breast carcinoma were studied. Whole tissue sections were used for in situ hybridization analysis. RESULTS: 8/100 (8 %) of ductal-type triple negative breast carcinoma presented Her-2/neu gene amplification versus 2/35 (5.7 %) non-ductal triple negative breast carcinoma. Three cases showed a ratio 2.5. One case showed Her-2/neu heterogeneous gene amplification, ratio 2.3. The other six showed from 7 to 8 absolute Her-2/neu gene copy number. Two cases staged pT1c, and eight cases staged pT2. Eight cases graded G3 and two cases G2. CONCLUSION: (1) Eight percentage of ductal and 5.7 % non-ductal-type triple negative breast carcinoma present Her-2/neu gene amplification, (2) the standard diagnostic flowchart "do not FISH in 0-1+ (HER2-) breast carcinoma" should be replaced by "do FISH in triple (ER-, PR-, HER2-) negative breast carcinoma," to avoid loss of therapeutical chances in a cohort of such a patients, (3) we demonstrated the identification of a small but significant subset of patients targetable with anti-HER2 inhibitors, giving patients affected by (ex)triple negative breast carcinoma new personalized therapeutical chances.

Breast ultrasound in 22,131 asymptomatic women with negative mammography.

PURPOSE: To evaluate increment cancer detection rate generated by ultrasound (US). MATERIALS AND METHODS: US only detected cancers were assessed for 22,131 self-referring asymptomatic women with negative mammography and subgroups by age, previous cancer, breast density. Invasive assessment and surgical biopsy rate were evaluated. RESULTS: The overall US detection was 1.85 per thousand (41/22,131). In the subgroups it was: 1.95 per thousand (22/11,274) in women <50 years vs 1.75 per thousand (19/10,857) in women ≥ 50 years (p = 0.42), 5.49 per thousand (12/2183) in women with previous cancer vs 1.45 per thousand (29/19,948) in women without cancer history (p = 0.0004), 2.21 per thousand (22/9960) in dense breasts (p = 0.17) vs 1.56 per thousand (19/12,171) in fatty breasts. The US generated invasive assessment was 1.9% (422/22,131). The benign to malignant open surgical biopsy ratio was 0.17 (7/41). CONCLUSION: Adding US to negative mammography allowed for substantial incremental cancer detection rate (1.85 per thousand), particularly at age <50 years, in women with previous breast cancer and in dense breasts.

FGFR-1 amplification in metastatic lymph-nodal and haematogenous lobular breast carcinoma.

BACKGROUND: Lobular breast carcinoma usually shows poor responsiveness to chemotherapies and often lacks targeted therapies. Since FGFR1 expression has been shown to play pivotal roles in primary breast cancer tumorigenesis, we sought to analyze the status of FGFR1 gene in a metastatic setting of lobular breast carcinoma, since promising FGFR1 inhibitors has been recently developed. METHODS: Fifteen tissue metastases from lobular breast carcinomas with matched primary infiltrative lobular breast carcinoma were recruited. Eleven cases showed loco-regional lymph-nodal and four haematogenous metastases.FGFR-1 gene (8p12) amplification was evaluated by chromogenic in situ hybridization (CISH) analysis. Her-2/neu and topoisomerase-IIα gene status was assessed. E-cadherin and Hercept Test were also performed. We distinguished amplification (>6 or cluster of signals) versus gains (3-6 signals) of the locus specific FGFR-1 gene. RESULTS: Three (20%) primary lobular breast carcinomas showed >6 or cluster of FGFR1 signals (amplification), six cases (40%) had a mean of three (range 3-6) chromogenic signals (gains) whereas in 6 (40%) was not observed any abnormality. Three of 15 metastasis (20%) were amplified, 2/15 (13,4%) did not. The ten remaining cases (66,6%) showed three chromogenic signals.The three cases with FGFR-1 amplification matched with those primary breast carcinomas showing FGFR-1 amplification. The six cases showing FGFR-1 gains in the primary tumour again showed FGFR-1 gains in the metastases. Four cases showed gains of FGFR-1 gene signals in the metastases and not in the primary tumours. Her-2/neu gene amplification was not observed in all cases but one (6%) case. Topoisomerase-IIα was not amplified in all cases. CONCLUSIONS: 1) a subset of metastatic lobular breast carcinoma harbors FGFR-1 gene amplification or gains of chromogenic signals; 2) a minor heterogeneity has been observed after matching primary and metastatic carcinomas; 3) in the era of tailored therapies, patients affected by the lobular subtype of breast carcinoma with FGFR1 amplification could be approached to the new target biological therapy such as emerging FGFR-1 inhibitors.

Classical lobular breast carcinoma consistently lacks topoisomerase-IIα gene amplification: implications for the tailored use of anthracycline-based chemotherapies.

AIMS: There is consistent lack of data focusing the topoisomerase-IIα gene status in lobular breast carcinoma, a subtype that usually shows poor responsiveness to chemotherapies including those using anthracycline drugs. METHODS AND RESULTS: Forty-six infiltrative lobular carcinomas, 13 with matched metastases, were used. Topoisomerase-IIα gene amplification was evaluated by chromogenic in situ hybridization (CISH) and fluorescence in situ hybridization (FISH). We also assessed Her2/neu status by CISH, FISH and silver in situ hybridization (SISH). HER2 immunoexpression was assessed by the HercepTest. Forty-four of 46 (95%) cases revealed no topoisomerase-IIα amplification, whereas two of 46 (5%) cases were amplified by all three techniques. Eleven of the 13 metastatic sites showed no amplification either in the primary or in the metastases (85%); the remaining two were amplified (15%). Her2/neu was not amplified in 44 of 46 (95%) cases nor was it amplified in 11 of 13 (95%) metastatic tissues. The two cases showing Her2/neu and topoisomerase-IIα amplification scored 3+; the remaining non-amplified cases scored 0 or 1+ in 40 and 2+ in four cases. CONCLUSIONS: In the era of personalized and tailored therapies, we suggest that patients affected by the classical lobular subtype of breast carcinoma constantly lack the ad hoc predictive rationale for receiving common chemotherapy that includes anthracyclines.

Cathepsin K expression in the spectrum of perivascular epithelioid cell (PEC) lesions of the kidney.

The perivascular epithelioid cell (PEC) is a unique cell type coexpressing contractile proteins (mainly α-smooth muscle actin), melanocytic markers, including microphthalmia-associated transcription factor (MITF), and estrogen and progesterone receptors. It is constantly present in a group of tumors called PEComas. Renal PEComas include the common angiomyolipoma as well as less common lesions such as microscopic angiomyolipoma, intraglomerular lesions, angiomyolipoma with epithelial cysts, epithelioid angiomyolipoma, oncocytoma-like angiomyolipoma and lymphangioleiomyomatosis of the renal sinus. It has been demonstrated that most of these lesions are determined by mutations affecting genes of the tuberous sclerosis complex, tuberous sclerosis 1 (TSC1) and tuberous sclerosis 2 (TSC2), with eventual deregulation of the RHEB/MTOR/RPS6KB2 pathway, and it has been observed that some PEComas regressed during sirolimus therapy, an MTOR inhibitor. Recently, overexpression of MITF has been related to the expression of the papain-like cysteine protease cathepsin K in osteoclasts where it has inhibited MTOR. The aim of this study is to evaluate cathepsin K immunohistochemically in the entire spectrum of PEComa lesions in the kidney. The study population consisted of 84 renal PEComa lesions, including 5 composed predominantly of fat (lipoma-like angiomyolipoma), 15 almost exclusively composed of spindle-shaped smooth muscle cells (leiomyoma-like angiomyolipoma) and 31 common angiomyolipomas composed of a mixture of fat, spindle and epithelioid smooth muscle cells, and abnormal thick-walled blood vessels, 15 microscopic angiomyolipomas, 5 intraglomerular lesions, 2 oncocytoma-like angiomyolipomas, 8 epithelioid angiomyolipomas, 2 angiomyolipomas with epithelial cysts and 1 example of lymphangioleiomyomatosis of the renal sinus. In all of the renal PEComas, cathepsin K was found to be constantly and strongly expressed and seems to be a more powerful marker than other commonly used markers for their identification, especially to confirm the diagnosis on needle biopsies.

Differential expression of cathepsin K in neoplasms harboring TFE3 gene fusions.

Cathepsin K is a protease whose expression is driven by microphthalmia transcription factor (MITF) in osteoclasts. TFE3 and TFEB are members of the same transcription factor subfamily as MITF and all three have overlapping transcriptional targets. We have shown that all t(6;11) renal cell carcinomas, which harbor an Alpha-TFEB gene fusion, as well as a subset of the Xp11 translocation renal carcinomas, which harbor various TFE3 gene fusions, express cathepsin K, while no other common renal carcinoma does. We have hypothesized that overexpression of TFEB or certain TFE3 fusion proteins function like MITF in these neoplasms, and thus activate cathepsin K expression. However, the expression of cathepsin K in specific genetic subtypes of Xp11 translocation carcinomas, as well as alveolar soft part sarcoma, which harbors the same ASPSCR1-TFE3 gene fusion as some Xp11 translocation carcinomas, has not been addressed. We performed immunohistochemistry for cathepsin K on 14 genetically confirmed t(X;1)(p11;q21) carcinomas, harboring the PRCC-TFE3 gene fusion; eight genetically confirmed t(X;17)(p11;q25) carcinomas, harboring the ASPSCR1-TFE3 gene fusion; and 18 alveolar soft part sarcomas (12 genetically confirmed), harboring the identical ASPSCR1-TFE3 gene fusion. All 18 alveolar soft part sarcomas expressed cathepsin K. In contrast, all eight ASPSCR1-TFE3 carcinomas were completely negative for cathepsin K. However, 12 of 14 PRCC-TFE3 carcinomas expressed cathepsin K. Expression of cathepsin K distinguishes alveolar soft part sarcoma from the ASPSCR1-TFE3 carcinoma, harboring the same gene fusion. The latter can be useful diagnostically, especially when alveolar soft part sarcoma presents in an unusual site (such as bone) or with clear cell morphology, which raises the differential diagnosis of metastatic ASPSCR1-TFE3 renal cell carcinoma. The difference in expression of cathepsin K between the PRCC-TFE3 and ASPSCR1-TFE3 carcinomas, together with the observed clinical differences between these subtypes of Xp11 translocation carcinomas, suggests the possibility of functional differences between these two related fusion proteins.

Pure epithelioid PEComas (so-called epithelioid angiomyolipoma) of the kidney: A clinicopathologic study of 41 cases: detailed assessment of morphology and risk stratification.

Epithelioid angiomyolipomas (perivascular epithelioid cell tumors) of the kidney are defined as potentially malignant mesenchymal lesions that are closely related to classic angiomyolipoma. Although approximately 120 cases are published, mostly as case reports with variably used diagnostic criteria, the pathologic prognostic predictors of outcome are unknown. We analyzed the clinicopathologic parameters in a large series of 41 cases of pure epithelioid angiomyolipomas of the kidney, which we designate as pure (monotypic) epithelioid PEComas to contrast them from classic angiomyolipomas that are regarded by some as PEComas. We use the terminology "pure" to separate these cases from those that may have variable epithelioid components. The mean age of the patients was 40.7 years (range, 14 to 68 y). The male-to-female ratio was 1:1. Seventy-nine percent of patients were symptomatic at presentation with metastatic disease at onset in 12 cases. Follow-up and/or disease progression information were available for 33 of 41 cases (mean, 44.5 mo and median, 24.5 mo; range, 4 to 240); 9 patients had a history of associated tuberous sclerosis. Recurrence and metastasis were seen in 17% and 49% of patients; 33% of patients died of disease. Lymph node involvement was seen in 24% of patients; the liver (63%), lung (25%), and mesentery (18.8%) were the most common metastatic sites. Clinicopathologic parameters associated with disease progression (recurrence, metastasis, or death due to disease) in univariate analysis included associated tuberous sclerosis complex or concurrent angiomyolipoma (any metastasis, P=0.046), necrosis (metastasis at diagnosis, P=0.012), tumor size >7 cm (progression, P=0.021), extrarenal extension and/or renal vein involvement (progression, P=0.023), and carcinoma-like growth pattern (progression, P=0.040) (the 5 adverse prognostic parameters for pure epithelioid PEComas). Tumors with <2 adverse prognostic parameters (13 cases) were considered to be low risk for progression tumor, with 15% having disease progression. Tumors with 2 to 3 adverse prognostic parameters (14 cases) were considered to be "intermediate risk," with 64% having disease progression. Tumors with more than 4 or more adverse prognostic parameters (6 cases) were considered to be high risk, with all patients having disease progression. Of tumors with 3 or more adverse prognostic parameters, 80% had disease progression. An exact logistic regression analytic model showed that only carcinoma-like growth pattern and extrarenal extension and/or renal vein involvement were significant predictors of outcome (P=0.009 and 0.033, respectively). Our data of a large series with uniform definitional criteria confirm the malignant potential for pure epithelioid PEComas and provide adverse prognostic parameters for risk stratification in these patients.

Molecular pathology of lymphangioleiomyomatosis and other perivascular epithelioid cell tumors.

CONTEXT: Lymphangioleiomyomatosis (LAM) is a cystic lung disease that can be included in the wide group of proliferative lesions named PEComas (perivascular epithelioid cell tumors). These proliferative tumors are characterized by the coexpression of myogenic and melanogenesis-related markers. In all these lesions, genetic alterations related to the tuberous sclerosis complex (TSC) have been demonstrated. Striking improvements in the understanding of the genetic basis of this autosomal dominant genetic disease are coupled to the understanding of the mechanisms that link the loss of TSC1 (9q34) or TSC2 (16p13.3) genes with the regulation of the Rheb/m-TOR/p70S6K pathway. These data have opened a new era in the comprehension of the pathogenesis of LAM and have also suggested new therapeutic strategies for this potentially lethal disease. OBJECTIVE: To present and discuss the pathologic and molecular features of LAM within the spectrum of PEComas, providing a rational approach to their diagnosis. DATA SOURCES: The published literature and personal experience. CONCLUSIONS: The inclusion of LAM within the PEComa category is supported by a variety of biologic data and can significantly help in providing a comprehensive view of this interesting and clinically relevant group of lesions. The demonstration of molecular alterations of the mTOR pathway in LAM and other PEComas represents a rational basis for innovative therapeutic approaches with inhibitors of mTOR signaling.

Cancer size, histotype, and cellular grade may limit the success of fine-needle aspiration cytology for screen-detected breast carcinoma.

BACKGROUND: Fine-needle aspiration cytology (FNAC) was adopted as the first-line method to assess breast lesions in the Verona Breast Cancer Screening Program. The radiological and pathological factors relating to the success of FNAC in breast cancer series were evaluated. METHODS: Between July 1999 and June 2004, 418 breast cancers were submitted to FNAC in the Verona Breast Cancer Screening Program. The results of FNAC diagnoses were compared with final histology. The FNAC sensitivity rate, underestimation of malignancy rate, and inadequacy rate were correlated with histotype, size, grading, and radiologic imaging. RESULTS: Of the 418 cancers, 95 were in situ, and 323 were invasive. The sensitivity rate was higher in invasive cancers (P < .001), and the underestimation of malignancy rate was greater in in situ cancers (P = .002). Lobular type cancers had a lower sensitivity rate in invasive and in situ cancers. The sensitivity rate was 100% in medullary, mucinous, and papillary cancers, and no case had inadequate sampling. The underestimation of malignancy rate was higher in tubular carcinoma (18.2%); lobular carcinoma showed a higher inadequacy rate (10.4%). The sensitivity rate was lower and the underestimation of malignancy rate was higher in low-grade carcinomas and in lesions <1 cm (P < .001). The performance of FNAC was not significantly influenced by mammographic imaging of lesions. CONCLUSIONS: Low-grade cancer histotype, cancer size <1 cm, and lobular and tubular histotypes limit the possibility of obtaining positive results by FNAC. Operator experience and multidisciplinary consultation may help in overcoming these limitations. Pathologists must be aware of the limits of FNAC; results must be critically evaluated in light of the triple assessment.