Effect of Formalin Fixation on Surgical Margins in Patients With Oral Squamous Cell Carcinoma

Surgical Management of Equine Neoplasia

Equine neoplasia poses challenges in surgical management owing to their diverse locations and potential for aggressive behavior. Surgical interventions aim for complete excision while minimizing cosmetic and functional impairments. Techniques such as laser ablation and electrochemotherapy offer minimally invasive options for accessible tumors. For deeper or larger masses, surgical excision with adequate margins remains the gold standard. Preoperative biopsy and imaging guides surgical planning, ensuring complete tumor removal while preserving vital structures. Close adherence to a strict surgical protocol to prevent seeding of tumor cells, and, where possible, appropriate skin reconstruction techniques will improve cosmesis and outcome.

Cutaneous tissue samples show significant shrinkage during histopathological work-up: a real-world study

BACKGROUND

Excision and histological examination of cutaneous neoplasms are very common diagnostic and therapeutic procedures in dermatological practice. There are often discrepancies between tissue seize in vivo and after histopathological work-up. This may raise questions according to tumor sizes or safety margins.

METHODS

To investigate the effect of excision and histological processing on the properties of cutaneous neoplasms in real-life 401 specimens in 324 patients were prospectively investigated. Delineated excision margins of cutaneous neoplasms were documented prior to (T0) and post excision (T1). Length, width and thickness were measured after ≥48 h of formalin fixation (T2) and after sectioning (T3) on final histological slices. Accompanying parameters such as patient age, gender, anatomical site, and tumor entity were evaluated.

RESULTS

All post-processed tissue exhibited a significant (P<0.001) median (interquartile range) reduction in length, width and thickness of 21.0% (9.5-30.0), 30.7% (20.0-40.0), and 28.0% (4.8-46.7), respectively, irrespective of site, patient age or tumor entity. Maximum median (IQR) reduction for the length and the width was observed right after excision (17.0% [4.3-25.0] and 14.0% [11.1-28.6] reduction). No significant median (IQR) tissue changes between T1 and T2 were observed (length: 4.8% (-4.3-13.3); width: 0% (-17.6-11.1); thickness 0% (-32.0-20.0). Subgroup analyses showed significantly greater tissue shrinkage in younger patients and for tissue sample sites (trunk or lower extremities).

CONCLUSIONS

Most relevant shrinkage of cutaneous samples occurs right after excision. Age- and site-depended tissue contractility can influence these effects. Formalin fixation does not affect tissue shrinkage. Smaller tissue sizes on histopathological reports are to be expected.

Value of radiological depth of invasion in non-pT4 Oral tongue squamous cell carcinoma: implication for preoperative MR T-staging

OBJECTIVE

The prognostic stratification for oral tongue squamous cell carcinoma (OTSCC) is heavily based on postoperative pathological depth of invasion (pDOI). This study aims to propose a preoperative MR T-staging system based on tumor size for non-pT4 OTSCC.

METHODS

Retrospectively, 280 patients with biopsy-confirmed, non-metastatic, pT1-3 OTSCC, treated between January 2010 and December 2017, were evaluated. Multiple MR sequences, including axial T2-weighted imaging (WI), unenhanced T1WI, and axial, fat-suppressed coronal, and sagittal contrast-enhanced (CE) T1WI, were utilized to measure radiological depth of invasion (rDOI), tumor thickness, and largest diameter. Intra-class correlation (ICC) and univariate and multivariate analyses were used to evaluate measurement reproducibility, and factors' significance, respectively. Cutoff values were established using an exhaustive method.

RESULTS

Intra-observer (ICC = 0.81-0.94) and inter-observer (ICC = 0.79-0.90) reliability were excellent for rDOI measurements, and all measurements were significantly associated with overall survival (OS) (all p < .001). Measuring the rDOI on axial CE-T1WI with cutoffs of 8 mm and 12 mm yielded an optimal MR T-staging system for rT1-3 disease (5-year OS of rT1 vs rT2 vs rT3: 94.0% vs 72.8% vs 57.5%). Using multivariate analyses, the proposed T-staging exhibited increasingly worse OS (hazard ratio of rT2 and rT3 versus rT1, 3.56 [1.35-9.6], p = .011; 4.33 [1.59-11.74], p = .004; respectively), which outperformed pathological T-staging based on nonoverlapping Kaplan-Meier curves and improved C-index (0.682 vs. 0.639, p < .001).

CONCLUSIONS

rDOI is a critical predictor of OTSCC mortality and facilitates preoperative prognostic stratification, which should be considered in future oral subsite MR T-staging.

CLINICAL RELEVANCE STATEMENT

Utilizing axial CE-T1WI, an MR T-staging system for non-pT4 OTSCC was developed by employing rDOI measurement with optimal thresholds of 8 mm and 12 mm, which is comparable with pathological staging and merits consideration in future preoperative oral subsite planning.

KEY POINTS

• Tumor morphology, measuring sequences, and observers could impact MR-derived measurements and compromise the consistency with histology. • MR-derived measurements, including radiological depth of invasion (rDOI), tumor thickness, and largest diameter, have a prognostic impact on OS (all p < .001). • rDOI with cutoffs of 8 mm and 12 mm on axial CE-T1WI is an optimal predictor of OS and could facilitate risk stratification in non-pT4 OTSCC disease.

Oral cavity cancer and its pre-treatment radiological evaluation: A pictorial overview

PURPOSE

Oral cavity cancer, primarily squamous cell carcinoma (SCC), is a prevalent malignancy globally, necessitating accurate clinical assessment and staging to enable effective treatment planning. Diagnosis requires biopsy and is followed by surgical resection and reconstruction as the primary therapeutic modality. Imaging plays a pivotal role during this process, aiding in the evaluation of tumour extent, nodal involvement and distant metastases. However, despite its value, both radiologists and clinicians must recognise its inherent limitations.

METHODS

This pictorial review article aims to illustrate the application of various imaging modalities in the pre-treatment evaluation of oral cavity SCC and highlights potential pitfalls. It underscores the importance of understanding the anatomical subsites of the oral cavity, the diverse patterns of spread tumours exhibit at each site, alongside the role of imaging in facilitating informed management strategies, while also acknowledging its limitations.

RESULTS

The review delves into fundamentals of current staging including nodal involvement, while, emphasising imaging strategies and potential limitations. Finally, it touches on the potential of novel radiomic techniques in characterising tumours and predicting treatment response.

CONCLUSIONS

Pre-treatment oral cavity cancer staging reflects an ongoing quest for enhanced diagnostic accuracy and prognostic prediction. Recognising the value of imaging alongside its limitations fosters a multidisciplinary approach to treatment planning, ultimately improving patient outcomes.

Intraoral Ultrasound versus MRI for Depth of Invasion Measurement in Oral Tongue Squamous Cell Carcinoma: A Prospective Diagnostic Accuracy Study

Oral squamous cell carcinoma (OSCC) of the tongue is the most common type of oral cavity cancer, and tumor depth of invasion (DOI) is an important prognostic factor. In this study, we investigated the accuracy of intraoral ultrasound and magnetic resonance imaging (MRI) for assessing DOI in patients with OSCC. Histopathological measurement of DOI was used as a reference standard. We conducted a prospective study including patients planned for surgical treatment of OSCC in the tongue. The DOI was measured in an outpatient setting by intraoral ultrasound and MRI, and was compared to the histopathological DOI measurements. Bland-Altman analysis compared the mean difference and 95% limits of agreement (LOA) for ultrasound and MRI, and the Wilcoxon signed-rank test was used to test for significance. The correlation was evaluated using Pearson's correlation coefficient. We included 30 patients: 26 with T1 or T2 tumors, and 4 with T3 tumors. The mean difference from histopathology DOI was significantly lower for ultrasound compared to MRI (0.95 mm [95% LOA -4.15 mm to 6.06 mm] vs. 1.90 mm [95% LOA -9.02 mm and 12.81 mm], p = 0.023). Ultrasound also led to significantly more correct T-stage classifications in 86.7% (26) of patients compared to 56.7% (17) for MRI, p = 0.015. The Pearson correlation between MRI and histopathology was 0.57 (p < 0.001) and the correlation between ultrasound and histopathology was 0.86 (p < 0.001). This prospective study found that intraoral ultrasound is more accurate than MRI in assessing DOI and for the T-staging of oral tongue cancers. Clinical practice and guidelines should implement intraoral ultrasound accordingly.

Efficacy of radiological depth of invasion measurements on magnetic resonance images acquired at different magnetic field strengths and imaging sequences in predicting cervical lymph node metastasis and other outcomes in tongue cancer

OBJECTIVES

We investigated the correlation between magnetic resonance imaging (MRI) parameters and tumor pathological depth of invasion (pDOI), between pDOI and radiological DOI (rDOI), between rDOI and duration between biopsy and MRI, and between rDOI and duration between MRI and surgery to determine the efficacy of rDOI in identifying small lesions and other conditions.

STUDY DESIGN

We examined 36 adult patients who had been diagnosed histopathologically with cancer of the tongue and had undergone a glossectomy. Using 1.5 Tesla (T) and 3.0T MRI, we measured rDOI at the deepest infiltration point on 4 MRI sequences. We calculated the correlations between rDOI and the variables examined by Spearman rho analysis and evaluated the diagnostic performance of rDOI by receiver operating characteristic curve analysis.

RESULTS

Axial T2-weighted images using 1.5T MRI provided the closest approximation of pDOI. Although the correlation between rDOI and pDOI was significant, rDOI showed poor or acceptable discrimination in identifying small lesions and other conditions. There were no significant correlations between rDOI and the time between biopsy and MRI or between MRI and surgery.

CONCLUSIONS

The correlation between rDOI and pDOI is significant, but rDOI is ineffective in predicting malignancy and other conditions. Axial T2-weighted images using 1.5T MRI provide the closest approximation of pDOI.

Prediction Formula for Pathological Depth of Invasion From Clinical Depth of Invasion in Tongue Squamous Cell Carcinoma (SCC) Stage I/II Cases

BACKGROUND

 The depth of invasion (DOI) of tongue squamous cell carcinoma (SCC) is an important prognostic factor. The definition is clear for pathological DOI (pDOI), but the treatment strategy is determined by the preoperative clinical DOI (cDOI). Few studies have investigated the difference between these DOIs. The purpose of this study was to obtain the correlation equation between cDOI and pDOI for Stage I/II tongue SCC and to consider the points to be noted in actual clinical practice.

METHODS

 In this retrospective study, 58 patients with clinical stage I/II tongue SCC were included. Correlations between cDOI and pDOI were obtained for all 58 cases, as well as for 39 cases which excluded superficial and exophytic lesions.

RESULTS

 The overall cDOI and pDOI median values were 8.0 and 5.5 mm, respectively; the 2.5 mm reduction was significant (p < 0.01). The correlation equation was pDOI = 0.81 × cDOI-0.23 (r = 0.73). Furthermore, re-analysis of the 39 cases revealed that pDOI = 0.84 × cDOI-0.37 (r = 0.62). Hence, a derived equation pDOI = 0.84 × (cDOI-0.44) was obtained to predict pDOI from cDOI.

CONCLUSIONS

 This study indicated that it is necessary to consider contraction due to specimen fixation by subtracting the thickness of the mucosal epithelium. Clinical T1 cases with a cDOI of 5 mm or less had a pDOI of 4 mm or less, and it would be expected to have low positive rate of neck lymph node metastasis.

Usefulness of reconstructed images of Gd-enhanced 3D gradient echo sequences with compressed sensing for mandibular cancer diagnosis: comparison with CT images and histopathological findings

OBJECTIVES

To compare the delineation of mandibular cancer by 3D T1 turbo field echo with compressed SENSE (CS-3D-T1TFE) images and MDCT images, and to compare both sets of images with histopathological findings, as the gold standard, to validate the accuracy and clinical usefulness of CS-3D-T1TFE reconstruction.

METHODS

Twenty-four patients with mandibular squamous cell carcinoma (SCC) who underwent MRI including CS-3D-T1TFE and MDCT examinations before surgery were retrospectively included. For both examinations, 0.5-mm-thick coronal plane images and 0.5-mm-thick plane images perpendicular and parallel to the dentition were constructed. Two radiologists rated bone invasion in three categories indexed by cortical bone, cancellous bone, and mandibular canal (MC), and inter-rater agreement was assessed by weighted kappa statistics. In 20 of the 24 patients who underwent surgery, the correlation of bone invasion with the histopathological evaluation by pathologists was assessed using Pearson's correlation coefficient. Soft-tissue invasion was assessed by diagnosing the presence of invasion into the mylohyoid muscle, gingivobuccal fold, and masticator space, and inter-rater agreement was assessed by kappa statistics.

RESULTS

The interobserver agreement for bone invasion assessment was almost perfect with CS-3D-T1TFE and substantial with MDCT. The image evaluations by both observers agreed with the pathological evaluations in 15 of the 20 cases, showing high correlation (r > 0.8). CS-3D-T1TFE also showed higher inter-rater agreement than MDCT for all measures of soft-tissue invasion.

CONCLUSIONS

CS-3D-T1TFE reconstructed images were clinically useful in accurately depicting the extent of mandibular cancer invasion and potentially solving the problem of lesion overestimation associated with conventional MRI.

KEY POINTS

• Reconstructed CS-3D-T1TFE images were useful for the diagnosis of mandibular cancer. • CS-3D-T1TFE images showed higher inter-rater agreement than MDCT and high correlation with pathological findings. • CS-3D-T1TFE images may solve the problem of overestimation of the tumor extent, which has been associated with MRI in the past.

Effect of formalin fixation on tumour size and margins in head and neck cancer specimens

Objectives

To quantify tumour size and margin shrinkage due to formalin fixation in head and neck cancer specimens and determine its effect on tumour staging and margin clearance.

Methods

Tumour specimens were measured immediate post-resection and at 24 hours after fixation. Tumour was measured in 2 dimensions and one margin was measured. Shrinkage was categorised as < 10%, 10-20%, and > 20%. Effect of shrinkage on tumour stage and margin clearance were evaluated.

Results

A total of 50 specimens were analysed. The tumour AP (Anterior Posterior) and SI (Superior Inferior) measurements showed significant shrinkage with a mean difference of 22.93% and 21.69% respectively. > 20% shrinkage was noted in 78% of AP and 58% of SI measurements. Margins showed a mean difference of 25.61%. 84% of margins demonstrated > 20% shrinkage. In all, 46.7% of T3 and 23% of T2 tumours pre-fixation were downstaged to T2 and T1, respectively, post-fixation.

Conclusions

Formalin fixation alone can be responsible for significant shrinkage of tumour and margin dimensions in head and neck specimens. It is suggested that decisions regarding the treatment plan should be made on clinical staging of primary tumour rather than pathological staging. In addition, post-excision pre-fixation margins should be considered for treatment planning.

Review:Surgical Tumour Margins and their Significance in Oral Squamous Cell Carcinoma

There are many prognostic indicators used to predict tumour recurrence and overall prognosis in oral squamous cell carcinoma (OSCC). Most of these biological factors cannot be directly influenced by clinicians managing these heterogeneous group of tumours. Excision margins can potentially be increased at the time of surgery by including more normal tissue than the commonly accepted 1cm resection distance from the macroscopic tumour edge. However, this can lead to poorer quality of life for patients and does not necessarily address microscopic extensions or dicohesive patterns of tumour growth. Surgical margins can be affected by tissue shrinkage immediately following resection, and the choice of instrument used for surgery. Currently most regard a clear resection margin as being >5mm, a close margin as more than 1mm but less than 5mm, and an involved margin less than 1mm. In this article we provide a brief overview of tumour margins in OSCC, including several recently published large meta-analyses. Based upon these and other studies, there is still conflicting data in the literature about the ideal margin for OSCC. There is a growing body of evidence which suggests a clearance of 1mm might be adequate for some cancers. However, adequacy of resection should be considered along with the many other prognostic indicators of OSCC when the multi-disciplinary team considers further treatment for these patients.

MRI before biopsy correlates with depth of invasion corrected for shrinkage rate of the histopathological specimen in tongue carcinoma

The purpose of this study was to evaluate which radiological depth of invasion (r-DOI) measurement is the most concordant to clinical DOI (c-DOI) derived from correction for the shrinkage rate of the histopathological specimens. We retrospectively reviewed 128 patients with tongue carcinoma who had undergone glossectomy between 2006 and 2019. At first, the width shrinkage rate during formalin fixation and preparation process of histopathological specimens was evaluated. From the shrinking rates, a formula to calculate c-DOI from pathological DOI (p-DOI) was developed. The correlation between c-DOI and r-DOI was evaluated. The specimen shrinkage rate during the histopathological specimen preparation process was 10.3%. Based on that, we yielded the correct formula for c-DOI based on p-DOI and preparation shrinkage rate: c-DOI = p-DOI × 100/89.7. The regression equations for the association of c-DOI with r-DOI measured by ultrasound (n = 128), MRI before biopsy (n = 18), and MRI after biopsy (n = 110) were y = 1.12 * x + 0.21, y = 0.89 * x − 0.26, and y = 0.52 * x + 2.63, respectively, while the coefficients of determination were 0.664, 0.891, and 0.422, respectively. In conclusion, r-DOI using MRI before biopsy most strongly correlated with c-DOI.

Assessment of tumor depth in oral tongue squamous cell carcinoma with multiparametric MRI: correlation with pathology

OBJECTIVES

To compare the correlation of depth of invasion (DOI) measured on multiple magnetic resonance imaging (MRI) sequences and pathological DOI, in order to determine the optimal MRI sequence for measurement.

METHODS

A total of 122 oral tongue squamous cell carcinoma (OTSCC) patients were retrospectively analyzed, who had received preoperative MRI and surgical resection. DOIs measured on fat-suppressed T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), dynamic enhanced-T1 high-resolution insotropic volume examination (e-THRIVE), and contrast-enhanced fat-suppressed T1WI (CE-T1WI) were respectively compared to those measured in pathologic specimens. The cutoff value of the best correlated MRI sequence was determined, and the T staging accuracy of MRI-derived DOI was evaluated.

RESULTS

DOI derived from e-THRIVE showed the best correlation (r = 0.936, p < 0.001) with pathological DOI. The area under the curve values of MRI-derived DOI distinguishing T1 stage from T2 stage and distinguishing T2 stage from T3 stage were 0.969 and 0.974, respectively. The T staging criteria of MRI-derived DOI were 6.2 mm and 11.4 mm, with a staging accuracy of 86.9% compared to pathological DOI criteria of 5 mm and 10 mm.

CONCLUSION

E-THRIVE was the optimal MR sequence to measure the MR-derived DOI, and DOI derived from e-THRIVE could serve as a potential cut-off value as a clinical T staging indicator of OTSCC.

KEY POINTS

• Multiparametric MRI helps radiologists to assess the neoplasm invasion in patients with oral tongue squamous cell carcinoma. • Retrospective study indicated that measurement was most accurate on enhanced-T1 high-resolution insotropic volume examination dynamic contrast enhancement images. • T staging of oral tongue squamous cell carcinoma was accurate according to the dynamic contrast enhancement MRI-derived depth of invasion.

Three-Dimensional Presentation of Tumor Histopathology: A Model Using Tongue Squamous Cell Carcinoma

Medical imaging often presents objects in three-dimensional (3D) form to provide better visual understanding. In contrast, histopathology is typically presented as two-dimensional (2D). Our objective was to present the tumor dimensions in 3D by creating a 3D digital model of it and so demonstrate the location of the tumor and the histological slices within the surgical soft tissue resection specimen. We developed a novel method for modeling a tongue squamous cell carcinoma using commonly available instruments. We established our 3D-modeling method by recognizing and solving challenges that concern the selection of the direction of histological slices. Additional steps to standard handling included scanning the specimen prior to grossing and modeling the carcinoma, which required only a table scanner and modeling software. We present challenges and their solutions in modeling the resection specimen and its histological slices. We introduce a finished 3D model of a soft tissue resection specimen and the actual tumor as well as its histopathological grossing sites in 3D digital and printed form. Our novel method provides steps to create a digital model of soft tissue resection specimen and the tumor within. To our knowledge, this is the first attempt to present histopathological margins of a tongue tumor in 3D form, whereas previously, only 2D has been available. The creation of the 3D model does not call for predetermined grossing directions for the pathologist. In addition, it provides a crucial initiative to enhance oncological management. The method allows a better visual understanding of tumor margins, topography, and orientation. It thus provides a tool for an improved postoperative assessment and aids, for example, in the discussion of the need for additional surgery and adjuvant therapy.

Specimen-driven intraoperative assessment of resection margins should be standard of care for oral cancer patients

With an incidence of 350.000 new cases per year, cancer of the oral cavity ranks among the 10 most common solid organ cancers. Most of these cancers are squamous cell carcinomas. Five-year survival is about 50%. It has been shown that clear resection margins (>5 mm healthy tissue surrounding the resected tumor) have a significant positive effect on locoregional control and survival. It is not uncommon that the resection margins of oral tumors are inadequate. However, when providing the surgeon with intraoperative feedback on the resection margin status, it is expected that obtaining adequate resection margins is improved. In this respect, it has been shown that specimen-driven intraoperative assessment of resection margins is superior to defect-driven intraoperative assessment of resection margins. In this concise report, it is described how a specimen-driven approach can increase the rate of adequate resections of oral cavity squamous cell carcinoma as well as that it is discussed how intraoperative assessment can be further improved with regard to the surgical treatment of oral cavity squamous cell carcinoma.

Intraoperative Assessment of the Resection Specimen Facilitates Achievement of Adequate Margins in Oral Carcinoma

Background

Inadequate resection margins in oral cavity squamous cell carcinoma have an adverse effect on patient outcome. Intraoperative assessment provides immediate feedback enabling the surgeon to achieve adequate resection margins. The goal of this study was to evaluate the value of specimen-driven intraoperative assessment by comparing the margin status in the period before and the period after the introduction of specimen-driven assessment as a standard of care (period 2010-2012 vs period 2013-2017).

Methods

A cohort of patients surgically treated for oral squamous cell carcinoma at the Erasmus MC Cancer Institute, Rotterdam, between 2010-2012 was studied retrospectively and compared to results of a prospectively collected cohort between 2013-2017. The frequency, type and results of intraoperative assessment of resection margins were analyzed.

Results

One hundred seventy-four patients were included from 2010-2012, 241 patients were included from 2013-2017. An increase in the frequency of specimen-driven assessment was seen between the two periods, from 5% in 2010-2012 to 34% in 2013-2017. When performing specimen-driven assessment, 16% tumor-positive resection margins were found in 2013-2017, compared to 43% tumor-positive resection margins overall in 2010-2012. We found a significant reduction of inadequate resection margins for specimen-driven intraoperative assessment (p < 0.001). Also, tumor recurrence significantly decreased, and disease-specific survival improved when performing specimen-driven intraoperative assessment.

Conclusions

Specimen-driven intraoperative assessment improves resection margins and consequently, the outcome of oral cancer patients. We advocate this method as standard of care.

The Effect of Diathermy Power Settings on Oral Cavity Mucosal Contraction: A Rat Model

OBJECTIVES/HYPOTHESIS

The effects of different electrocautery power settings on mucosal contraction and margin status in the oral cavity have not been well established. The aim of this study was to examine how different levels of electrocautery energy outputs affect oral mucosal tissue margins.

STUDY DESIGN

Animal model.

METHODS

A model of 23 adult rats was used (two specimens per rat). After anesthetizing the animals, a 6-mm biopsy punch marked the resection margin on the buccal mucosa (one per cheek). The specimens were excised by means of three energy levels, a cold knife, and monopolar diathermy that was set on either 20 W or 30 W cut modes. The specimens were evaluated for extent of contraction.

RESULTS

A total of 45 samples were obtained and measured, including 15 specimens in the cold-knife group, 15 specimens in the 20 W group, and 15 specimens in the 30 W group. The median diameters of the specimens after resection were 4.5 mm for the cold-knife group (interquartile range [IQR] = 4.0-5.0), 3.5 mm for the 20 W group (IQR = 3.5-4.0), and 2.8 mm for the 30 W group (IQR = 2.5-3.0). Specimen contraction was 25.0%, 41.7%, and 53.3%, respectively. The difference in shrinkage between each pair was statistically significant: cold knife versus 20 W, P = .001; cold knife versus 30 W, P < .0001; and 20 W versus 30 W, P < .001.

CONCLUSIONS

Diathermy power settings result in a significant difference of mucosal tissue contraction, with higher outputs resulting in a narrower mucosal margin. It is imperative that the surgical team take into consideration the diathermy settings during initial resection planning. Laryngoscope, 131:E1514-E1518, 2021.

Assessing the magnetic resonance imaging in determining the depth of invasion of tongue cancer

OBJECTIVES

To assess the magnetic resonance imaging (MRI) in predicting tumour's depth of invasion (DOI) of tongue cancer by comparing to pathology and to determine the cut-off value of MRI-derived DOI for lymph node metastasis.

PATIENTS AND METHODS

In a retrospective analysis, 156 patients with newly diagnosed tongue cancer were included. Tumour's DOI was compared between MRI measurement and pathology by Pearson correlation coefficient and paired t test. The accuracy of MRI-derived DOI was compared to the pathological DOI. The relationship between MRI-derived DOI and cervical lymph node metastasis was calculated by receiver operating characteristic curve.

RESULTS

Tumour's DOI was well correlated between MRI measurement and pathology with correlation coefficients of 0.77. MRI-derived DOI was 3.4 mm (28%) larger than pathology. The accuracy of MRI in deciding pathological DOI was 67.9%. The cut-off value of MRI-derived DOI was 10.5 mm for lymph node metastasis of tongue cancer.

CONCLUSION

Magnetic resonance imaging can be used as a reference to determine tumour's DOI of tongue cancer. Tumour with MRI-derived DOI larger than 10.5 mm deserves simultaneous neck dissection at initial surgery.

Surgical and histological boundary of the hepatic hilar plate system: basic study relevant to surgery for hilar cholangiocarcinoma regarding the "true" proximal ductal margin

BACKGROUND

We sought to expand the clinico-anatomical limit of the proximal ductal margin (Limit-PDM) for resectability of hilar cholangiocarcinoma (HCCA).

METHODS

The practical boundary of the hilar plate (PBHP) was defined as the location where the bile duct (BD) could not be isolated by dissection. The distance between PBHP and two well-known clinical landmarks of Limit-PDM, the right edge of the bifurcation of the anterior and posterior branch of the right portal vein (Posterior-Landmark) and the left edge of the umbilical portion of the portal vein (Left-Landmark), and histological features around the PBHP were assessed using 55 adult cadaver livers.

RESULTS

BD was almost always isolatable beyond the traditional clinical landmarks. The median distance was 6.9 mm (interquartile range [IQR] 6.0-8.3 mm) between the PBHP and the Posterior-Landmark, and 8.9 mm (IQR 6.7-10.2 mm) between the PBHP and the Left-Landmark. Histologically, the sheath surrounding the portal triad was loose, thick with few elastic fibers and small arteries near the hepatic hilum. Near the PBHP, the sheath was dense, thin, and abundant with elastic fibers and small arteries.

CONCLUSIONS

Limit-PDM is more peripheral than the traditional clinical landmark-based margin and histological transition near the PBHP was revealed.

Surgical Margins: The Perspective of Pathology

Neoplasms of the head and neck constitute a broad spectrum of benign and malignant entities. When treatment involves resection, assessment of the surgical margins represents an important component of the pathologic examination. Margin status is an important indicator of a complete surgical resection. The ability to generalize conclusions such as 'safe distance' measurements from work performed mSCCa or cutaneous malignancy to other types of neoplasms in the head and neck region seems limited. This article reviews conditions and considerations for reliable margin assessment and interpretation.