Laparoscopy-assisted transanal pull-through at the time of suction rectal biopsy: a new approach to treating selected cases of Hirschsprung disease

Aim

We present a new approach to treating selected cases of Hirschsprung disease (HD) where suction rectal biopsy (SRBx) is performed in an operating room, and rapid acetylcholinesterase staining (RAST) is used to identify histopathology within 20 minutes, allowing primary laparoscopy-assisted transanal pull-through (PLTPT) to be commenced “immediately” (n = 7).

Materials and Methods

All subjects had an obvious caliber change in the rectum/sigmoid colon on barium enema and were strongly suspected of having HD.

Results

Rapid acetylcholinesterase staining clearly demonstrated acetylcholinesterase-positive hypertrophic nerve trunks and absence of ganglion cells in all SRBx specimens, indicating that all 7 patients had HD. All 7 proceeded to uneventful PLTPT. By taking this approach, SRBx results were available extremely quickly, and hospital stay was reduced by 2 to 4 days.

Discussion

Our approach enhanced the treatment of selected cases of HD by proceeding immediately to PLTPT after SRBx specimens were examined using RAST.     

Anorectal sleeve micromanometry for the diagnosis of Hirschsprung's disease in newborns

Background/Purpose

An accurate diagnosis is mandatory for surgery in newborns with Hirschsprung's disease (HD). Acetylcholinesterase staining of rectal suction biopsy specimens is widely performed in the diagnosis of HD, but results are sometimes incorrect or atypical in newborns. We report the usefulness of our method of anorectal manometry using a specially designed sleeve microassembly for the diagnosis of neonatal HD.

Methods

Anorectal manometry was conducted without sedation in 41 newborns, aged 2 to 30 days (19 newborns were within the first week of life), with abdominal distension. A silastic assembly with a 2-cm-long sleeve sensor and 5 side holes arrayed along the sleeve was designed to reduce the effects of displacement of pressure sensors relative to the anal sphincter. Rectoanal inhibitory reflex (RAIR) was examined with rectal balloon distension.

Results

Thirty-two subjects who showed falls of anal sphincter pressure fulfilling the criteria for RAIR were diagnosed to be without HD. Nine patients without an appropriate RAIR were subsequently confirmed to have HD based on operative pathologic findings. Parameters of anal sphincter function did not differ significantly between the subjects with and without RAIR.

Conclusions

An anorectal sleeve micromanometric technique is useful in the diagnostic workup of newborns suspected of having HD.     

Predictive utility of cyclo-oxygenase-2 expression by colon and rectal cancer

Background

Cyclo-oxygenase-2 (COX-2), an inducible enzyme expressed in areas of inflammation, is a target of interest for colorectal cancer therapy. Currently, the predictive significance of COX-2 in colorectal cancer remains unclear.

Methods

Tissue microarrays were constructed using 118 colon cancer and 85 rectal cancer specimens; 44 synchronous metastatic colon cancer and 22 rectal cancer lymph nodes were also evaluated. COX-2 expression was assessed by immunohistochemistry. Univariate analysis was used to determine the predictive significance of clinicopathologic variables. Overall survival, disease-specific survival, and disease-free survival were the main outcomes examined.

Results

COX-2 was found to be expressed in 93% of colon cancers and 87% of rectal cancers. Decreased COX-2 expression was related to decreased disease-specific survival (P = .016) and decreased disease-free survival (P = .019) in the rectal cancer cohort but not in the colon cancer cohort.

Conclusions

COX-2 expression has predictive utility for management of rectal but not colon cancer.     

Aberrant expression of laminin γ2 correlates with poor prognosis and promotes invasion in extrahepatic cholangiocarcinoma

Background

To investigate the potential role of laminin γ2 and its correlation with prognosis in patients with extrahepatic cholangiocarcinoma (CCA).

Materials and methods

Laminin γ2 expression was evaluated by immunohistochemistry in 72 extrahepatic CCA patients after surgical resection. Knockdown of laminin γ2 was achieved via small interfering RNA transfection in the extrahepatic CCA cell line QBC939.

Results

Thirty-six of 72 extrahepatic CCAs (50%) stained positive for laminin γ2 in two types of patterns: stromal staining (28/72, 39%) and cytoplasmic staining (24/72, 33%). All 16 paracancerous tissue samples showed negative staining. Both stromal and cytoplasmic laminin γ2 expressions correlated with lymph node metastasis. Kaplan-Meier analysis showed that aberrant expression of laminin γ2 correlated with poor overall survival and early recurrence. Cox regression analysis further demonstrated that laminin γ2 expression was a significant independent predictor of poor overall survival and early recurrence. Immunofluorescence staining revealed cytoplasmic expression of laminin γ2 in QBC939 cells. Knockdown of laminin γ2 significantly reduced QBC939 cell invasion and migration.

Conclusions

Aberrant expression of laminin γ2 correlates with poor prognosis and promotes invasion in extrahepatic CCA.     

p27 expression in post-treatment rectal cancer: a potential novel approach for predicting residual nodal disease

Background

Expression profiles of p21, p27, p53, Ki-67, and thymidylate synthase may be associated with response to neoadjuvant chemoradiation. The relationship between post-treatment protein expression and regional lymph node involvement has not been fully explored.

Methods

Tumor cores from 126 rectal cancer patients underwent immunohistochemical analysis for the aforementioned proteins. Staining indices (SIs) using percentage of stained cells and staining intensity were calculated for 10 tumor cores per patient. SI for each marker was compared between node negative and node positive patients.

Results

Twenty-six (20.6%) cancer patients had a pathologic complete response and 37 had inadequate tissue or cancer cells, leaving 63 for analysis. Thirty-seven (58.7%) cancer patients were node negative and 26 (41.3%) were node positive. There was an association between increased p27 SI and nodal positivity (P = .04).

Conclusion

Increased p27 expression in post-treatment rectal cancer is associated with nodal positivity and may determine which patients are suitable for local excision.     

High TFAP2C/low CD44 expression is associated with an increased rate of pathologic complete response following neoadjuvant chemotherapy in breast cancer

Background

In luminal breast cancer cell lines, TFAP2C regulates expression of key genes in the estrogen receptor–associated cluster and represses basal-associated genes including CD44. We examined the effect of TFAP2C overexpression in a basal cell line and characterized the expression of TFAP2C and CD44 in breast cancer specimens to determine if expression was associated with clinical response.

Methods

MDA-MB-231 breast cancer cells were treated with a TFAP2C-containing plasmid and evaluated for effects on CD44 expression. Pretreatment biopsy cores from patients receiving neoadjuvant chemotherapy for breast cancer were evaluated for TFAP2A, p53, TFAP2C, and CD44 expression by immunohistochemistry.

Results

Overexpression of TFAP2C in MDA-MB-231 cells resulted in decreased expression of CD44 mRNA and protein, P < 0.05. A pathologic complete response (pCR) following neoadjuvant chemotherapy was achieved in 17% of patients (4/23). Average expression for TFAP2C by immunohistochemistry in patients with a pCR was 93%, compared with 46% in patients with residual disease, P = 0.016; and in tumors that stained at ≥80% for TFAP2C, 4 of 9 (44%) achieved pCR, compared with 0 of 14 below 80%, P = 0.01. Additionally, in tumors that stained ≤80% for CD44, 4 of 10 (40%) achieved pCR, compared with 0 of 13 >80%, P = 0.02. In tumors that stained high for TFAP2C (≥80%) and low for CD44 (≤80%), 4 of 7 (57%) achieved pCR, compared with 0 of 16 in all other groups (P = 0.004).

Conclusions

TFAP2C repressed CD44 expression in basal-derived breast cancer. In primary breast cancer specimens, high TFAP2C and low CD44 expression were associated with pCR after neoadjuvant chemotherapy and could be predictive of tumors that have improved response to neoadjuvant chemotherapy.     

The prevalence of Hirschsprung disease in premature infants after suction rectal biopsy

Background

The prevalence of Hirschsprung disease (HD) in the premature infant population is not well documented. However, delayed passage of stool is common in premature infants, and suction rectal biopsy (SRB) is often used to evaluate for HD in this population. The use of SRB is unknown. Therefore, we evaluated the role of SRB in premature infants with abnormal stooling patterns.

Methods

After Institutional Review Board approval, a retrospective study was conducted on all infants having an SRB performed to exclude HD from January 2000 to December 2010. Infants were divided into two groups according to gestational age (premature < 37 wk; term ≥ 37 wk). Demographics, diagnosis, treatments, and outcomes were collected. A subset analysis was performed on patients diagnosed with HD.

Results

Two hundred sixty-nine infants were identified (113 premature and 156 term). Six premature infants (5.3%) and 79 term infants (50.6%) were found to have HD (P < 0.01). As expected, gestational age was significantly different between groups (31.7 versus 38.9 wk, P < 0.01) (Table 1). Premature infants were less likely to have prenatal care (35% versus 55%, P < 0.01) and had longer lengths of hospital stay (45.6 versus 17.6 d, P < 0.01). The most common location of aganglionosis was rectosigmoid in both groups (group 1, 50%; group 2, 33%, P = 0.7).

Conclusions

HD occurs significantly less often in premature infants than in term infants. Alternative diagnoses should be investigated in this population when delayed stooling patterns are encountered. SRB should be used more selectively in this group.     

Lovastatin prevents discography-associated degeneration and maintains the functional morphology of intervertebral discs

Background context

Discography is an important diagnostic approach to identify the painful discs. However, the benefit of discography, a procedure involving needle puncture and injection of the diagnostic agent into the intervertebral disc, is controversial and has been reported to be associated with accelerated degeneration.

Purpose

To investigate the effect of lovastatin on the prevention of degeneration caused by a discography simulation procedure in rat caudal discs.

Study design

In vivo study using rat caudal discs.

Methods

A single flexible 27-gauge needle puncture into rat caudal discs was performed under fluoroscopic monitoring. Different concentrations (0.1, 1, 5, and 10 μM) of lovastatin were prepared and injected into randomly chosen caudal discs. RNA expression of selected genes, histologic, and immunohistochemical staining were performed to evaluate the phenotypic effects of lovastatin on rat caudal discs.

Results

Simulation of the discography procedure by puncturing the rat caudal discs with a 27-gauge needle and injection of saline solution induced degenerative changes in the nucleus pulposus with minimal damage to the annulus fibrosus. Aggrecan, Type II collagen, and SOX9 expressions were upregulated, whereas Type I collagen expression was significantly suppressed in discs treated with 5 and 10 μM lovastatin. Discs treated with 5 and 10 μM lovastatin were subjected to alcian blue staining and immunohistochemistry that revealed higher levels of glycosaminoglycans and an increase in the number of cells producing S-100 proteins, Type II collagen, and bone morphogenetic protein-2 (BMP-2), respectively. The most effective phenotypic repair was observed in discs treated with 10 μM lovastatin.

Conclusions

Intradiscal administration of lovastatin solution upregulated the expressions of BMP-2 and SOX9 and promoted chondrogenesis of rat caudal discs after needle puncture and substance injection. Therefore, we suggest that lovastatin promotes disc repair and can be used as a potential therapeutic agent for biological repair of disc degeneration after the diagnostic discography procedure.     

Systematic Review of Complications of Prostate Biopsy

Context

Prostate biopsy is commonly performed for cancer detection and management. The benefits and risks of prostate biopsy are germane to ongoing debates about prostate cancer screening and treatment.

Objective

To perform a systematic review of complications from prostate biopsy.

Evidence acquisition

A literature search was performed using PubMed and Embase, supplemented with additional references. Articles were reviewed for data on the following complications: hematuria, rectal bleeding, hematospermia, infection, pain, lower urinary tract symptoms (LUTS), urinary retention, erectile dysfunction, and mortality.

Evidence synthesis

After biopsy, hematuria and hematospermia are common but typically mild and self-limiting. Severe rectal bleeding is uncommon. Despite antimicrobial prophylaxis, infectious complications are increasing over time and are the most common reason for hospitalization after biopsy. Pain may occur at several stages of prostate biopsy and can be mitigated by anesthetic agents and anxiety-reduction techniques. Up to 25% of men have transient LUTS after biopsy, and <2% have frank urinary retention, with slightly higher rates reported after transperineal template biopsy. Biopsy-related mortality is rare.

Conclusions

Preparation for biopsy should include antimicrobial prophylaxis and pain management. Prostate biopsy is frequently associated with minor bleeding and urinary symptoms that usually do not require intervention. Infectious complications can be serious, requiring prompt management and continued work into preventative strategies.     

Modified transanal rectosigmoidectomy for Hirschsprung's disease: clinical and manometric results in the initial 20 cases

Purpose

The authors describe a modified technique of primary transanal rectosigmoidectomy for Hirschsprung’s disease (HD), using a Swenson like procedure to perform the anastomosis between the colon and the rectum, and the preliminary results from this in children.

Methods

Twenty children, of whom, 90% were boys and 10% girls, 50% white and 50% nonwhite, aged 15 days to 10 years and with HD proven via biopsy, underwent a transanal pull-through procedure over a 29-month period. Postoperative follow-up ranged from 29 to 5 months. The proximal cut edge of the mucosal and submucosal cuff was tagged with multiple polypropylene 4-0 sutures, which were used for traction of the intestinal layers outside. The rectal mucosa was incised circumferentially using cautery, to perform rectal dissection approximately 1.5 cm from the dentate line, except in newborn case, in which the proximal cut edge was 0.5 cm from the dentate line. The dissection extended in an upward direction around the entire rectal circumference as far as the opening of the peritoneal reflection. The full thickness of rectum and sigmoid were mobilized outside through the anus, with division and coagulation of the rectal and sigmoid vessels using cautery or ligatures with cotton 4-0. The dissected colon then was divided above the transition zone, which was confirmed via full-thickness biopsy sections and with frozen section confirmation of ganglion cell presence. The authors performed a modified Swenson anastomosis technique, using a seromuscular polyglactin 4-0 separate-stitch suture. No drains were used.

Results

Normal bowel movements were displayed by all patients at the follow-up. All patients underwent a defecogram and anorectal computerized manometry at 3 months after surgery that showed an absence of stenosis and good anorectal sphincter muscle complex function. The incidence of complications in our series was 10%.

Conclusions

During the follow-up period of 29 months, all patients had normal bowel movements and normal anorectal manometric pressure profiles.     

Long-Term Endoscopic Follow-up in Small Bowel Transplant Recipients: Single-Center Series

Background

The reliability of endoscopic findings after adult intestinal transplantation on short-term follow-up has been shown. The aim of this study was to evaluate in a long-term follow-up the diagnostic value of endoscopies compared with the biopsy value.

Methods

We evaluated 52 endoscopies over a period of 2 years (2 in each patient in 2010 and 1 in each patient in 2011, plus 1 endoscopy for suspected post-transplant lymphoproliferative disease [PTLD]) on 17 recipients transplanted between the years 2000 and 2006 (more than 5 years of follow-up).

Results

All the 52 endoscopic findings were comparable to biopsy definitive results: only 1 case of mild enteritis and 1 case of Epstein-Barr virus (EBV) chronic infection at biopsy were not diagnosed by endoscopy. One case of rectal PTLD and 1 of EBV-related enteritis were diagnosed by use of both procedures. Specificity was 98%: we did not calculate sensitivity because no episodes of rejection were diagnosed because recipients were stable in long-term follow-up.

Conclusions

Endoscopy is a reliable procedure even on a long-term follow-up after intestinal transplantation, allowing a support to biopsy for diagnosis on adult recipients, especially for EBV infections and PTLD surveillance.     

Fast evaluation of intraoperative biopsies for ganglia in Hirschsprung's disease

Purpose

The most important diagnostic features of Hirschsprung's disease (HD) are the combination of aganglionosis and hypertrophic nerve bundles. Acetylcholinesterase staining is widely used for diagnosis of HD as it identifies hypertrophic nerves in both diagnostic and intraoperative biopsies. The main drawback of this method is in the identification of ganglia. It has been suggested that the combination of this method together with another histochemical marker would be a superior diagnostic tool. Hematoxylin and eosin is still the diagnostic measure of choice for identifying ganglia in many centers, although it presents a persistent diagnostic challenge for pathologists trying to rapidly and accurately interpret the frozen biopsies that guide intraoperative decision making.

Methods

Therefore, we sought to develop a fast, intraoperative immunohistochemical protocol for visualization of ganglia and nerves in HD specimens that can be used in conjunction with these other tools.

Results

With the use of acetone fixation and immunofluorescence staining with antibodies to neurofilament 68 and tubulin, ganglia in sections of full thickness and suction biopsies could be visualized in only 10 minutes. This protocol facilitated the identification of ganglia in hematoxylin and eosin-stained adjacent sections and also identified hypertrophic nerve trunks.

Conclusion

This method should significantly enable the identification of ganglia in suction and full thickness biopsies.     

Induction of chemokine (C-C motif) ligand 2 by sphingosine-1-phosphate signaling in neuroblastoma

Background/purpose

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood. Preliminary data derived from a human angiogenesis array in NB showed that the bioactive lipid sphingosine-1-phosphate (S1P) induced the secretion of several angiogenesis-related proteins including the important inflammatory factor chemokine (C-C motif) ligand 2 (CCL2). In the present study, we investigated the mechanism of S1P-induced CCL2 expression in NB.

Methods

Quantitative real-time PCR and CCL2 ELISA were conducted to detect the mRNA expression and protein secretion of CCL2 in NB cells. Gain and loss of function studies were performed by using specific S1PR antagonists, adenoviral transduction and siRNA transfection. Macrophage F4/80 receptor in NB xenografts was detected by quantitative real-time PCR and immunohistochemistry staining.

Results

S1P induced CCL2 mRNA expression and protein secretion in a time- and concentration-dependent manner in NB cells. Blockade of S1P₂ signaling using the selective S1P₂ antagonist JTE-013 inhibited S1P-induced CCL2 expression. Overexpression of S1P₂ by adenoviral transduction increased CCL2 secretion while knockdown of S1P₂ by siRNA transfection decreased S1P-induced CCL2 secretion in NB cells. Macrophage infiltration, as detected by F4/80 staining, was significantly decreased in JTE-013-treated NB xenografts.

Conclusions

Taken together, our data for the first time demonstrate that S1P induced the macrophage-recruiting factor CCL2 expression in NB cells via S1P₂, providing new insights into the complicated functions of S1P₂ in cancer.     

Hemorrhoidal laser procedure: short- and long-term results from a prospective study

Background

We report the results of 2-year regular use of the hemorrhoidal laser procedure (HeLP) in 97 patients with symptomatic second- to third-grade hemorrhoids with minimal or moderate internal mucosal prolapse.

Methods

Data on duration of the procedure, perioperative complications, postoperative pain, downgrading of hemorrhoids, resolution or persistency, and recurrence of hemorrhoidal disease (HD) were prospectively collected.

Results

No significant intraoperative complications occurred. The median follow-up was 15 months. Postoperative pain was null in most patients. There were no cases of rectal tenesmus or alteration of defecation habits. Symptoms and HD downgrading reached a “plateau” at 3 to 6 months after the HeLP. At this evaluation, frequency of bleeding, pain, itching, and hemorrhoidal acute syndrome decreased by 76% to 79%. HD grade showed a significant reduction. HD recurrence rate was 5% at 2 years.

Conclusions

Our study demonstrates that the HeLP is a safe, effective, and painless technique for the treatment of symptomatic second- to third-grade hemorrhoids with minimal or moderate mucosal prolapse, ideally suitable as ambulatory treatment.     

Inflammatory Protein Serum Amyloid A1 Marks a Subset of Conventional Renal Cell Carcinomas with Fatal Outcome

Background

Conventional renal cell carcinoma (RCC) is the most common renal cancer. As the metastatic conventional RCC is practically incurable, there is a need for markers to estimate the tumour aggressiveness.

Objective

To identify and characterise new marker(s) associated with the poor prognosis of conventional RCC.

Design, Setting, and Participants

RNA from 24 conventional RCCs was analysed for global gene expression by Affymetrix U133 Plus 2.0 arrays. Tissue microarrays containing 224 renal tumours including 87 conventional RCCs were used for immunohistochemistry. Cell lines HD2, HD48, HA344 and HA465 established in our laboratory were used for invasion assay and zymography.

Measurements

Serum amyloid A 1 (SAA1) was found to be upregulated in conventional RCCs and it has been analysed by quantitative RT-PCR and immunohistochemistry on TMAs to establish the correlation between SAA1 protein expression and patient survival by uni and multivariate analysis. The effect of SAA1 on tumour cell behaviour in vitro has also been examined by invasion assay and zymography.

Results and Limitations

SAA1 RNA is expressed in conventional RCC samples of patients with poor prognosis. Immunohistochemistry of 72 conventional RCCs with a 5 yr follow up showed a correlation between SAA1 expression and the clinical outcome of disease. Stimulation of conventional RCC cell lines with recombinant SAA1 increased the expression of metalloproteinase (MMP)-9 and the invasive potential of tumour cells. Limitation of the study is a relatively small number (72) of patients having follow up.

Conclusion

SAA1 seems to be a useful marker to estimate the prognosis of conventional RCCs.     

Down-regulation of MeCP2 in Hirschsprung's disease

Background/Purpose

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of intramural ganglion cells which are highly associated with impaired proliferation and migration of neural crest cells. Whether methyl CpG binding protein 2 (MeCP2) is related with HSCR still remains unknown. This study investigates the involvement of MeCP2 in HSCR.

Methods

Quantitative real time PCR and western blot were used to detect the expression level of MeCP2 both in the aganglionic/diseased segment and the ganglionic/normal segment. In vitro assays we used siRNAs to knock-down the expression of MeCP2 in SH-SY5Y cell lines, and furthermore, MTT and transwell assays were used to detect the proliferation and migration ability, respectively. In addition, bisulfite sequencing (BSP) and miRNA analysis were used to examine why MeCP2 is decreased in HSCR samples.

Results

MeCP2 exhibited a lower expression level in tissues of HSCR patients compared with the controls. The down-regulation may also suppress the proliferative ability of the cells. However, there was no significant difference in the MeCP2 methylation level between cases and controls. Similarly, there was no difference between cases and controls in miRNA-34b (miR-34b) which is predicted to regulate MeCP2 through complementary binding to the 3′-untranslated region of MeCP2.

Conclusion

Our results indicated that an aberrant decreased level of MeCP2 may play an important role in the pathogenesis of HSCR.     

Overexpression of ELAV-like protein HuR is associated with increased COX-2 expression in atrophy, high-grade prostatic intraepithelial neoplasia, and incidental prostate cancer in cystoprostatectomies

Background

The human ELAV-like protein HuR regulates the stability of several mRNA targets, including that of cyclooygenase-2 (COX-2). Their expression in prostatic carcinogenesis is uncertain.

Objective

To analyze HuR and COX-2 expression in cystoprostatectomies (CyPs) with incidental prostate cancer and compare their expression with those in radical prostatectomies (RPs) with clinically detected cancer.

Design, setting, and participants

HuR and COX-2 were immunohistochemically evaluated in normal-looking epithelium (NEp), atrophy, high-grade prostatic intraepithelial neoplasia (HGPIN), and prostate carcinoma (PCa) in 20 CyPs and 20 RPs, both types of specimens with pT2a Gleason score 6 PCa.

Measurements

At least 1000 cells were counted in contiguous 400X microscopic fields in each case, separately for NEp, atrophy, HGPIN, and PCa.

Results and limitations

There was an increase in the percentage of secretory cells with cytoplasmic HuR staining from NEp to atrophy, HGPIN, and PCa. The mean percentages in NEp, atrophy, and HGPIN adjacent to PCa were greater than away from cancer, both in the CyP and RPs. There was a trend towards a reduced nuclear HuR expression in atrophy, HGPIN, and PCa, compared to NEp. COX-2 staining was seen in the cytoplasm of the basal and secretory cells. There was a reduction in the mean proportion of positive basal cells and progressive increase in the percentage of positive secretory cells from atrophy to HGPIN and PCa, compared to NEp. Cytoplasmic HuR overexpression was correlated with COX-2 expression. There was no difference in HuR and COX-2 expression between cancers with tumour volume <0.5 ccm or >0.5 ccm.The limitations of this study were the small number of cases investigated and lack of a control group without cancer.

Conclusions

The secretory cells showed shift in HuR staining from nuclear in NEp to cytoplasmic in PCa. This is associated with a parallel shift in COX-2 expression from basal to secretory cells.     

Rationale for percutaneous biopsy and histologic characterisation of renal tumours

Context

The use of percutaneous biopsy of renal tumours has been traditionally reserved for selected cases because of uncertainties regarding its safety, accuracy, and clinical utility. With the adoption of modern biopsy techniques and increasing expertise in interpreting biopsy specimens, renal tumour biopsy today has limited morbidity and allows histologic diagnosis in the majority of cases in centres with expertise.

Objective

To review the current rationale, indications, and outcomes of percutaneous biopsies and histologic characterisation of renal tumours.

Evidence acquisition

We conducted a systematic review of English-language articles on percutaneous biopsies of renal tumours published between January 1999 and December 2011 using the Medline, Embase, and Web of Science databases. One hundred twelve articles were selected with the consensus of all authors and analysed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria.

Evidence synthesis

In recent years, the increasing incidence of incidental small renal masses (SRMs), the development of conservative and minimally invasive treatments for low-risk renal cell carcinoma (RCC), and the discovery of novel targeted treatments for metastatic disease have provided the rationale for expanding the indications for renal tumour biopsy. Percutaneous biopsy for diagnostic assessment of SRMs can avoid unnecessary surgeries and support treatment decisions, especially in patients at high surgical risk. Biopsies can confirm histologic success after thermal ablation of SRMs and support the selection of the appropriate systemic therapy for metastatic RCC. There is increasing evidence that further diagnostic and prognostic information can be obtained from renal tumour biopsies with the use of immunohistochemistry, cytogenetic and molecular analysis, and high-throughput gene expression profiling.

Conclusions

Percutaneous biopsies have increasing indications and can significantly contribute to clinical management of renal tumours but are still underutilised in clinical practice. Further research is needed to define optimal and standardised patterns of biopsy and improve the accuracy of biopsies to determine tumour histology. Molecular and genetic analysis of biopsy specimens can provide additional information to support patient counselling and treatment decision making.