Anatomic Abstracts
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March 2012 Editors:
It has been proposed that an adequate lymph node dissection for cases of endometrial carcinoma should contain a determined number of pelvic or para-aortic lymph nodes, or both. Consequently, the surgeons at the authors’ institution have expectations regarding the number of pelvic and para-aortic lymph nodes reported per case. Failure to meet these expectations has posed a challenge. In an attempt to solve this problem, the authors set out to ascertain whether a pathology factor, such as disregarding small lymph nodes not detected on gross examination, was responsible for any discrepancy between expected and reported lymph node counts. The authors evaluated the impact of microscopic examination of residual adipose tissue after routine processing of lymph node dissections performed as part of the staging procedure for patients with endometrial carcinoma (endometrioid, serous, and clear cell carcinoma) on the lymph node counts and statuses for hysterectomies performed between 2006 and the time of their study. The authors also assessed whether other factors, such as surgical procedure type, operating surgeon, histologic subtype of carcinoma, depth of myometrial invasion, or body mass index, had an impact on the number of lymph nodes obtained. The number of pelvic and para-aortic lymph nodes were recorded for the study. All lymph node specimens were processed by dissecting the nodes from the surrounding adipose tissue. The number of lymph nodes submitted per cassette was recorded in the section code. In cases in which residual adipose tissue was submitted, hematoxylin-and-eosin–stained slides of the additional tissue were reviewed to determine the number and size of any additional lymph nodes and their status. The authors found that 258 patients had a median of 11 pelvic lymph nodes (range, one to 38) and six para-aortic nodes (range, one to 25). Fifty of 78 cases (64 percent) in which residual adipose tissue was submitted had additional lymph nodes (median size, 4.0 mm): median, two pelvic and three para-aortic nodes. There was no significant association between the number of lymph nodes obtained and whether the residual adipose tissue was submitted (pelvic lymph node, P=0.2; para-aortic lymph node, P=0.78). There were no cases in which metastatic endometrial carcinoma was present exclusively in the additional lymph nodes. Compared with open hysterectomy, lymphadenectomy specimens obtained laparoscopically and robotically had an average of three and 0.8 more para-aortic lymph nodes, respectively (P=0.002). No similar association was found for pelvic or total lymph nodes. The authors observed evidence for some difference in lymph node counts between surgeons. They did not identify any evidence of an association between body mass index, histologic subtype of endometrial carcinoma, or depth of myometrial invasion and lymph node count. In the authors’ experience, the standard processing of lymphadenectomy specimens reflects the number of lymph nodes obtained in cases of endometrial carcinoma. Submitting the residual adipose tissue does not increase the number of reported lymph nodes nor the detection of positive nodes. The authors concluded that additional studies are required to determine the number of pelvic and para-aortic lymph nodes present and to determine whether it is necessary to revise the number of lymph nodes required to consider a lymphadenectomy to be adequate. Euscher ED, Bassett R, Malpica A. Lymph node counts in endometrial cancer: expectations versus reality. Am J Surg Pathol. 2011;35(6):913–918. Correspondence: Elizabeth D. Euscher at edeusche@mdanderson.org
New editions of the TNM staging system for colorectal cancer have been subject to extensive criticism. The authors conducted a study in which they evaluated each edition of the TNM (tumor-node-metastasis) system and analyzed stage migration caused by the different versions. The evaluation focused on two independent test populations: participants derived from a randomized surgical trial in the United Kingdom (n=455) and patients from a population-based series in Sweden (n=505). The authors reviewed all slides from these patient cases, paying particular attention to finding tumor deposits. Tumor deposits were classified according to the fifth, sixth, and seventh editions of TNM and correlated with prognosis. The authors found that every change in edition of TNM led to a stage migration of 33 percent to 64 percent in patients with tumor deposits. Reproducibility was best in the fifth edition of TNM. The prognostic value of the seventh edition was best only when all tumor deposits, irrespective of size or contour, were included as lymph nodes. The prognostic value of the fifth edition was better than that of the sixth. The authors demonstrated that there is a place for tumor deposits in the staging of patients with colorectal cancer. However, many questions still surround their definition and the reproducibility and use of this category in special situations, such as after neoadjuvant treatment. The authors concluded that tumor deposits should undergo additional research before being used as a factor in TNM staging. Nagtegaal ID, Tot T, Jayne DG, et al. Lymph nodes, tumor deposits, and TNM: Are we getting better? J Clin Oncol. 2011;29(18):2487–2492. Correspondence: Dr. Iris D. Nagtegaal at i.nagtegaal@pathol.umcn.nl
Percutaneous radio-frequency ablation is increasingly used for curative treatment of primary cancers of the kidney. The authors reviewed their experience with percutaneous sampling performed under computed tomographic guidance with fine-needle aspiration biopsy (FNAB) and core biopsy. They reported on the complementary roles of these two techniques in a series of 351 consecutive patients undergoing radio-frequency ablation for renal neoplasms. Both FNAB and core biopsy were obtained in 290 cases, of which 156 patients (54 percent) were positive for neoplasm in both specimens and 27 (nine percent) were negative for tumor in both specimens. In 58 (20 percent) patients, the FNABs were positive but the core biopsies were negative, and the reverse occurred in 11 patients (four percent). When suspicious interpretations by FNAB and core biopsy were included as positives in the calculations, both their complementary nature and the relative higher diagnostic yield of FNAB persisted. In 25 cases with FNABs positive for neoplasm, the core biopsy allowed a more specific tumor classification. The 19 cases of FNAB which were read as negative/benign had corresponding core biopsies that were also negative/benign in 13 cases. Yet six cases were diagnostic of renal cell carcinoma not otherwise specified (one case), renal cell carcinoma clear cell/conventional (four cases), and non-Hodgkin lymphoma (one case). The authors concluded that these results and additional findings illustrate the complementary value of the combination of the two biopsy methods for a reliable pretherapy morphologic confirmation of specific renal neoplasms. FNAB has relatively greater sensitivity and utility for on-site evaluation, whereas core biopsy provides an additional sample for more specific subclassification and additional studies. Parks GE, Perkins LA, Zagoria RJ, et al. Benefits of a combined approach to sampling of renal neoplasms as demonstrated in a series of 351 cases. Am J Surg Pathol. 2011;35(6):827–835. Correspondence: Dr. Graham E. Parks at geparks@wfubmc.edu
Mucocele-like lesions of the breast are ruptured ducts that discharge their contents into the stroma. They constitute a spectrum that ranges from benign to atypical to malignant. The current management of these lesions, diagnosed on core biopsy, is excision. The authors conducted a study to evaluate the necessity of this practice for benign mucocele-like lesions. Retrospective review of a pathology database from Jan. 1, 2000 to June 1, 2008 identified 61 cases, with followup information available for 50 of them. Clinical, radiological, and pathological information was correlated. Core biopsies were reviewed to confirm the diagnosis and verify previous biopsy site. Forty-five of the patients underwent surgery, whereas five patients were followed for more than one year and remained stable. Patients ranged from 44 to 76 years old. Most benign mucoceles were diagnosed stereotactically while targeting calcifications (93.3 percent). The lesion was rarely a mass detected sonographically. Eighty-two percent (37 of 45) of excisions had no residual mucocele. In seven cases (15.6 percent), atypical duct hyperplasia was present. Three had residual mucocele. In one case, the residual mucocele showed a continuum from florid to atypical duct hyperplasia at the core biopsy site. The other six cases showed atypical duct hyperplasia adjacent to but not directly at the core biopsy site. The sizes of the benign mucoceles ranged from incipient to 0.6 cm, with all but one, which was incidental, containing calcifications. Radiological-pathological correlation was concordant in all cases except one with suspicious calcification, which was ductal carcinoma in situ on excision. In this series, which was the largest of its kind, the upstage rate of benign mucoceles diagnosed on core biopsy was 17.8 percent. With the exception of the ductal carcinoma in situ case, no radiological or morphological features were predictive of atypia. Therefore, because of associated atypical duct hyperplasia, sampling reasons, and intralesional heterogeneity, the authors continue to recommend excision of benign mucocele-like lesions diagnosed on core biopsy. Jaffer S, Bleiweiss IJ, Nagi CS. Benign mucocele-like lesions of the breast: revisited. Mod Pathol. 2011;24:683–687. Correspondence: Dr. S. Jaffer at shabnam.jaffer@msnyuhealth.org Anatomic pathology abstracts editors: Michael Cibull, MD, professor and vice chair, Department of Pathology and Laboratory Medicine, University of Kentucky College of Medicine, Lexington; Rouzan Karabakhtsian, MD, assistant professor of pathology and laboratory medicine, University of Kentucky College of Medicine; and Thomas Cibull, MD, dermatopathologist, Evanston Hospital, NorthShore University HealthSystem, Evanston, Ill. |
