HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sohaib, S. A. A. Articles by Reznek, R. H. Search for Related Content PubMed PubMed Citation Articles by Sohaib, S. A. A. Articles by Reznek, R. H. Social Bookmarking                      What's this?

MR Imaging of Carcinoma of the Vulva

¹ Department of Diagnostic Imaging, St. Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, United Kingdom.
² Present address: Academic Department of Diagnostic Radiology, Royal Marsden Hospital, Downs Rd., Sutton Surrey SM2 5PT, United Kingdom.
³ Department of Gynaecological Oncology, St. Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, United Kingdom.

Received May 7, 2001; accepted after revision August 20, 2001.

 
S. A. Sohaib was supported in part by a grant from the Joint Research Board, St. Bartholomew's Hospital.

Address correspondence to S. A. A. Sohaib.

Abstract

Top Abstract Introduction Materials and Methods Results Discussion References

 
OBJECTIVE. The aim of this study was to describe the MR imaging features of cancer of the vulva and to determine the accuracy of MR imaging in staging the disease.

MATERIALS AND METHODS. We reviewed the MR images of 22 patients (range, 21-85 years; median, 74 years) with cancer of the vulva who were treated at our institution between 1995 and 2000. Note was made of the primary tumor size, site, signal characteristics, enhancement, and local extension and of lymph node number, size, and position. The MR imaging features were correlated with surgical and pathologic findings.

RESULTS. The tumors were isointense to muscle on T1-weighted images and showed intermediate-to-high signal intensity on T2-weighted scans. After IV gadolinium was administered to four patients, tumor enhancement was seen in two (50%). MR imaging correctly staged the primary site in 14 (70%) of the 20 patients. If superficial inguinal nodes 10 mm or greater in short-axis diameter are considered abnormal, then the sensitivity for detection of malignant nodes was 40% and the specificity, 97%. If deep inguinal nodes 8 mm or greater in short-axis diameter are considered abnormal, then the sensitivity for detection of malignant nodes was 50% and the specificity, 100%.

CONCLUSION. MR imaging is highly specific for the detection of nodal involvement in patients with cancer of the vulva but correlates only moderately with clinicopathologic staging of the primary tumor.

Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

 
Cancer of the vulva accounts for 3-5% of primary gynecologic malignancies [1,2,3]. Most patients are staged clinically using the International Federation of Gynecology and Obstetrics staging system [4]. The single most important prognostic factor, assuming adequate clearance of the primary site, is the presence or absence of nodal metastases [1, 5]. Preoperative assessment for nodal disease is performed clinically and often includes CT of the pelvis to detect nodal progression. However, clinical examination of inguinal nodes is unreliable in predicting groin metastases [6, 7]. Furthermore, cancer of the vulva, which is usually treated by radical vulvectomy and inguinal node dissection, is associated with considerable morbidity [1, 8, 9]. An accurate method for staging inguinal nodes in cancer of the vulva might reduce the need for such radical surgery and may also have an impact on the planning of radiotherapy.

MR imaging is being used more often in the treatment of gynecologic malignancy because MR imaging offers an opportunity to stage both the primary tumor and the regional lymph nodes. The role of MR imaging in cancer of the vulva has not been investigated previously, and the aim of this study was to describe the MR imaging features and to determine the accuracy of MR imaging in staging cancer of the vulva.

Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

 
We retrospectively reviewed the imaging, surgical, and pathologic findings in all patients with invasive squamous cell cancer of the vulva who had undergone MR imaging examination at our institution between 1995 and 2000. The diagnosis was confirmed at surgery and histopathology. Twenty-two patients were included, with an age range of 21-85 years (median, 74 years). In two cases, the patient had already undergone excision biopsy of the primary tumor, and MR imaging was performed before any further surgery.

MR imaging was performed on a Signa Horizon 1.5-T MR unit (General Electric Medical Systems, Milwaukee, WI). All patients underwent spin-echo T1-weighted (TR range/ TE range, 400-600/14-16) and fast spin-echo T2-weighted MR imaging (TR range/effective TE range, 5000-6500/95-120; echo-train length, 8-16) in the axial plane using a phased array multicoil. A field of view of 32-35 cm was used with a matrix size of 256 x 192-256 and 2-3 excitations. Fat-saturated spin-echo T1-weighted sequences before and after administration of 0.1mL/kg of gadodiamide dimeglumine (Omniscan; Nycomed, Amersham, United Kingdom) were also performed in four of the 22 patients.

MR images were reviewed in conference by two radiologists who were aware of the diagnosis but not of the surgical and pathologic findings. Size, site, signal characteristics, enhancement, and local extension of the primary tumor were assessed. The primary tumors were staged using the T category of the TNM classification, which is the same as in the International Federation of Gynecology and Obstetrics staging system [4]. T1 tumors are 2 cm or less in the greatest dimension, and T2 tumors are more than 2 cm in the greatest dimension and confined to the vulva or perineum. T3 tumors extend beyond the vulva to invade the lower urethra, vagina, or anus, and T4 tumors have invasion into the upper urethra, bladder mucosa, rectal mucosa, and pelvic bone [4]. Tumor size was determined by the greatest measurable diameter, and lesions not seen on MR imaging were classified as stage T1. Tumor site was classified as left, right, central, or bilateral. Signal characteristics were defined as low or high with respect to the signal intensity of skeletal muscle. An adjacent structure was considered involved if direct tumor invasion was shown or if a clear surrounding fat plane could not be seen on all images.

Tumor spread to the groin lymph nodes was assessed. Lymph nodes adjacent to the femoral vessels were classified as deep (femoral) nodes, and all other nodes were considered superficial (inguinal) nodes. Lymph node size was assessed using the short-axis diameters of the nodes. Surgical and pathologic findings were compared with MR imaging features, and staging by MR imaging was evaluated against clinicopathologic staging. Analysis of the lymph node status (i.e., benign or malignant) was performed on a groin-by-groin basis for the superficial inguinal and deep femoral node groups rather than on a node by node or patient by patient basis.

Statistical analysis was performed using SPSS (version 6.1.3) software (Statistical Package for the Social Sciences, Chicago, IL), with significance taken as p < 0.05. The Mann Whitney test was used to compare the size and total number of lymph nodes in diseased and disease-free groins.

Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
The primary lesion was seen on MR imaging in 10 of the 20 patients who underwent MR imaging before excision of the primary cancer of the vulva. In the patients in whom the primary lesion was not seen on MR imaging, tumors were 1 cm or less in thickness at histopathology. These 10 cases were, therefore, classified on MR imaging as stage T1. Of the T1 tumors at histopathology, five were not seen on MR imaging, and one patient had a 2 x 1 cm lesion. MR imaging overstaged one of the pathologically defined T1 tumors as a T2 lesion. This tumor measured 2.5 cm in length on MR imaging but less than 2 cm at histopathology. Five of the 13 stage T2 tumors were not identified on MR imaging (Fig. 1) and, therefore, were incorrectly classified as stage T1. Eight (62%) of the 13 T2 tumors were correctly identified on MR imaging (Fig. 2). None of the T2 tumors were overstaged. In four cases, clitoral involvement was correctly identified on MR imaging (Fig. 3). No patient had involvement of the vagina or anus. Overall MR imaging correctly staged the primary site in 14 (70%) of the 20 patients.

View larger version (160K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 1. —75-year-old woman with carcinoma of vulva that measured 3 x 2 cm with less than 2-mm depth of invasion that was not visualized on MR imaging. Axial T2-weighted fast spin-echo MR image fails to show tumor.

View larger version (104K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 2. —21-year-old woman with carcinoma of vulva. Axial T2-weighted fast spin-echo MR image shows 3-cm tumor (arrow) arising from right labia.

View larger version (100K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 3. —75-year-old woman with large central carcinoma of vulva (straight arrow) involving clitoris (curved arrow). Axial T2-weighted fast spin-echo MR image shows intermediate-signal-intensity tumor extending to involve clitoris.

When the tumor could be identified on MR imaging, the site of the tumor was correctly identified in all patients. Seven of these patients had central or bilateral involvement (Fig. 3), and three had unilateral disease (Fig. 2). The tumors were isointense to muscle on T1-weighted and showed intermediate-to-high signal on T2-weighted sequences. The tumors were seen better on T2-weighted images compared with T1-weighted images or contrast-enhanced images. IV gadolinium was given in four patients, of whom two (50%) showed tumor enhancement and enhancement of the perineum.

Lymph node dissection was performed in 40 groins of 21 patients. Malignant nodes were found in nine groins in seven patients, being detected in the superficial (inguinal) group of nodes in five patients (Fig. 4) and the deep (femoral) group in four (Fig. 5). The malignant nodes were larger compared with benign nodes in both the inguinal (median, 9 mm vs 5 mm; p = 0.006, Mann Whitney test) and femoral (median, 7 mm vs 0 mm; p = 0.003, Mann Whitney test) group of nodes; however, there was considerable overlap (Fig. 6).

View larger version (136K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 4. —75-year-old woman with carcinoma of vulva with left superficial inguinal lymph node metastases. Axial T2-weighted fast spin-echo MR image shows enlarged left superficial inguinal lymph node (arrow).

View larger version (134K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 5. —58-year-old woman with carcinoma of vulva and bilateral femoral node metastases. Axial T2-weighted fast spin-echo MR image shows bilateral 8-mm femoral lymph nodes (arrows).

View larger version (7K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 6. —Scatter diagram shows relationship between size of lymph nodes (short-axis diameter) in benign and malignant nodes for inguinal and femoral groups of nodes. Note that although malignant nodes are larger, there is considerable overlap in size between benign and malignant lymph nodes.

The sensitivity and specificity for malignant nodes at various size thresholds are shown on the receiver operator characteristic curve (Fig. 7). If superficial inguinal nodes 10 mm or greater in short axis are considered abnormal, then the sensitivity for detection of malignant nodes is 40% and specificity is 97%. If femoral nodes 8 mm or greater in short-axis are considered abnormal, then the sensitivity for detection of malignant nodes is 50% and the specificity is 100%.

View larger version (10K): [in this window] [in a new window] [as a PowerPoint slide]   Fig. 7. —Receiver operating characteristic curve shows relationship between sensitivity and specificity for deep (femoral, ) and superficial (inguinal, •) nodes at different size (short-axis diameter) threshold criteria. Note that using size as criterion for malignant nodes results in high specificity but poor sensitivity.

Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

 
Our study has shown that primary cancer of the vulva can be identified on MR imaging. Most tumors show a characteristic signal-intensity pattern of low signal intensity on T1-weighted images and moderate-to-high signal intensity on T2-weighted images. In the few cases in which an IV contrast medium was administered, we did not find these patterns helpful in the identification of the primary lesion. When the tumor could be seen on MR imaging, its extent could be outlined. However, small primary tumors and tumors that were not thick (i.e., more plaque-like lesions) were not seen. This difference may have been due to imaging parameters not being optimal for the identification of small primary lesions in this retrospective study. Using high-resolution imaging with a small field of view and thinner sections may have identified more primary lesions.

The inguinal lymph nodes were easily detected on MR imaging, and individual groups of nodes were identified. The number and size of lymph nodes vary considerably in the normal population; this variation may explain the low sensitivity of MR imaging in detecting malignant adenopathy [10]. The low sensitivity on MR imaging means that the false-negative rate is high; therefore, at present, it may not be possible to avoid block dissection. However, because MR imaging is highly specific with these criteria, there are few false-positive findings; therefore, if a node is enlarged, the surgeon would have a high degree of confidence that the lymph node was involved. If the patient was a poor risk for surgery, then nonsurgical therapy could be used or limited node dissection considered.

Many techniques have been used to evaluate inguinal nodes in cancer of the vulva. Palpation is of limited use in the detection of abnormal inguinal lymph nodes, with a sensitivity of only 57% and a specificity of 62% [7]. Fine-needle aspiration cytology of inguinal lymph nodes without imaging guidance has a specificity of 100% but a sensitivity of only 58% due to the high false-negative rate from sampling errors [11]. Fine-needle aspiration cytology combined with sonography may be more accurate, with a reported accuracy of up to 89% [12]. Recently, interest has been shown in the use of lymphoscintigraphy both to show the path of lymphatic drainage and for intraoperative sentinel node mapping after peritumoral injection of a radiolabeled tracer [13,14,15]. The role of MR imaging in these different imaging modalities remains to be determined.

Our study has a number of limitations. There is a selection bias in the patients who underwent MR imaging examination. The retrospective nature of the study limits close correlation between the lymph nodes at imaging and at surgery. The imaging sequences were not optimized for the evaluation of small primary tumors.

In summary, in cancer of the vulva, MR imaging correlates moderately with the clinicopathologic staging of the primary disease but is highly specific for nodal metastases. MR imaging is likely to be of limited use in the assessment of small primary lesions that can be readily assessed clinically. MR imaging is likely to be of more benefit in the assessment of more locally advanced disease. With optimal MR imaging techniques, deep extension of the primary tumor and assessment of adjacent pelvic structures (e.g., anal sphincters) may be better assessed on MR imaging than at clinical examination. A further potential and important role for MR imaging may lie in the assessment of tumor spread to the inguinal lymph nodes. The cross-sectional imaging allows precise anatomic identification of pathologic nodes and, thus, aids in surgical planning. Also, MR imaging can accurately determine the depth of nodes from the skin surface, which varies markedly with patient body habitus [10], and this information could be invaluable in planning external beam radiotherapy [10, 16]. Furthermore, newer MR imaging contrast agents may improve the sensitivity and specificity of detecting lymph node involvement [17, 18].

References

Top Abstract Introduction Materials and Methods Results Discussion References

 

1. Homesley HD. Management of vulvar cancer. Cancer 1995;76:2159 -2170[Medline]
2. Joura EA, Losch A, Haider-Angeler MG, Breitenecker G, Leodolter S. Trends in vulvar neoplasia: increasing incidence of vulvar intraepithelial neoplasia and squamous cell carcinoma of the vulva in young women. J Reprod Med 2000;45:613 -615[Medline]
3. Crum CP. Carcinoma of the vulva: epidemiology and pathogenesis. Obstet Gynecol 1992;79:448 -454[Medline]
4. Sobin LH, Wittekind CH (International Union Against Cancer [UICC]), eds. TNM classification of malignant tumours, 5th ed. New York: Wiley-Liss, 1997
5. Homesley HD. Lymph node findings and outcome in squamous cell carcinoma of the vulva. Cancer 1994;74:2399 -2402[Medline]
6. Soutter WP, Lambert H, McIndoe AJ. Carcinoma of the vulva and its putative precursors. In: Peckham M, Pinedo H, Veronesi U, eds. Oxford textbook of oncology. Oxford: Oxford Univ. Press, 1995:1383 -1394
7. Piura B, Rabinovich A, Cohen Y, Friger M, Glezerman M. Squamous cell carcinoma of the vulva in the south of Israel: a study of 50 cases. J Surg Oncol 1998;67:174 -181[Medline]
8. Hacker NF, Leuchter RS, Berek JS, Castaldo TW, Lagasse LD. Radical vulvectomy and bilateral inguinal lymphadenectomy through separate groin incisions. Obstet Gynecol 1981;58:574 -579[Abstract/Free Full Text]
9. Podratz KC, Symmonds RE, Taylor WF, Williams TJ. Carcinoma of the vulva: analysis of treatment and survival. Obstet Gynecol 1983;61:63 -74[Abstract/Free Full Text]
10. Grey AC, Carrington BM, Hulse PA, Swindell R, Yates W. Magnetic resonance appearance of normal inguinal nodes. Clin Radiol 2000;55:124 -130[Medline]
11. Moskovic EC, Shepherd JH, Barton DP, Trott PA, Nasiri N, Thomas JM. The role of high resolution ultrasound with guided cytology of groin lymph nodes in the management of squamous cell carcinoma of the vulva: a pilot study. Br J Obstet Gynaecol 1999;106:863 -867[Medline]
12. Abang MDK, Uberoi R, de B Lopes A, Monaghan JM. Inguinal node status by ultrasound in vulva cancer. Gynecol Oncol 2000;77:93 -96[Medline]
13. de Hullu JA, Doting E, Piers DA, et al. Sentinel lymph node identification with technetium-99m-labeled nanocolloid in squamous cell cancer of the vulva. J Nucl Med 1998;39:1381 -1385[Abstract/Free Full Text]
14. De Cicco C, Sideri M, Bartolomei M, et al. Sentinel node biopsy in early vulvar cancer. Br J Cancer 2000;82:295 -299[Medline]
15. Barton DP, Berman C, Cavanagh D, et al. Lymphoscintigraphy in vulvar cancer: a pilot study. Gynecol Oncol 1992;46:341 -344[Medline]
16. McCall AR, Olson MC, Potkul RK. The variation of inguinal lymph node depth in adult women and its importance in planning elective irradiation for vulvar cancer. Cancer 1995;75:2286 -2288[Medline]
17. Bellin MF, Roy C, Kinkel K, et al. Lymph node metastases: safety and effectiveness of MR imaging with ultrasmall superparamagnetic iron oxide particles—initial clinical experience. Radiology 1998;207:799 -808[Abstract/Free Full Text]
18. Harisinghani MG, Saini S, Weissleder R, et al. MR lymphangiography using ultrasmall superparamagnetic iron oxide in patients with primary abdominal and pelvic malignancies: radiographic—pathologic correlation. AJR 1999;172:1347 -1351[Abstract/Free Full Text]

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				S Vessal and M Balogun Imaging of vulval carcinoma Imaging, August 1, 2006; 18(1): 28 - 34. [Abstract] [Full Text] [PDF]

				M. G. Harisinghani, W. T. Dixon, M. A. Saksena, E. Brachtel, D. J. Blezek, P. J. Dhawale, M. Torabi, and P. F. Hahn MR Lymphangiography: Imaging Strategies to Optimize the Imaging of Lymph Nodes with Ferumoxtran-10 RadioGraphics, May 1, 2004; 24(3): 867 - 878. [Abstract] [Full Text] [PDF]

This Article Abstract Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sohaib, S. A. A. Articles by Reznek, R. H. Search for Related Content PubMed PubMed Citation Articles by Sohaib, S. A. A. Articles by Reznek, R. H. Social Bookmarking                      What's this?