CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Evaluation of breast amyloidosis finds AL type most prevalent
Amyloidosis is a disorder characterized by extracellular deposition of proteins in an abnormal fibrillar configuration. Amyloidosis can be localized or systemic and may affect any organ. Breast involvement by amyloidosis has rarely been reported. The authors conducted a study in which they described the characteristics of 40 cases of breast amyloidosis that were reviewed in the division of anatomic pathology at the Mayo Clinic from 1995 to 2011. The cohort included 39 women and one man who were a mean age of 60 years. The type of amyloidosis, determined by immunohistochemistry or mass spectrometry-based proteomics in 26 patients, was immunoglobulin-associated in all cases (AL-kappa type in 15 [58 percent], AL-lambda in 10 [38 percent], and mixed heavy and light chains in one [four percent]). Mass spectrometry-based proteomics was able to determine the type of amyloidosis in 95 percent of cases tested compared with 69 percent of cases by immunohistochemistry. In addition to amyloidosis, the breast biopsy showed a hematologic disorder in 55 percent of cases, most commonly mucosa-associated lymphoid tissue (MALT) lymphoma. One patient had concurrent intraductal carcinoma, but none had invasive carcinoma. Of the 15 patients seen at this institution, 53 percent had localized amyloidosis and 47 percent had extramammary amyloid involvement, which was diagnosed before breast amyloidosis in most patients. M-spike was detected in the blood in 62 percent. After a median followup of 33.5 months in 12 patients, five died, mostly from complications of lymphoma or leukemia. The authors concluded that these findings indicate that breast amyloidosis is of the AL type in the vast majority of patients and is usually kappa. It is associated with systemic amyloidosis in close to half of patients and with hematologic malignancy in the breast in more than half of patients. Therefore, further work-up to rule out hematologic malignancy or systemic amyloidosis, or both, is recommended. Mass spectrometry-based proteomics is superior to immunohistochemistry for the typing of breast amyloidosis.
Said SM, Reynolds C, Jimenez RE, et al. Amyloidosis of the breast: predominantly AL type and over half have concurrent breast hematologic disorders. Mod Pathol. 2013;26:232–238.
Correspondence: Dr. J. M. Lee at said.samar@mayo.edu
Outside case review of surgical pathology for referred patients: impact on patient care
Pathologists at the Mayo Clinic review externally acquired surgical pathology materials from a referred patient prior to that patient’s clinical evaluation and treatment. The authors conducted a study to identify the rate of major disagreements between Mayo’s findings and those of other institutions and to characterize the nature and impact of discordant diagnoses on patient care. The authors identified and reviewed all surgical pathology cases, except for medical liver, medical renal, and cardiac pathology cases, from Jan. 1, 2005 to Dec. 31, 2010 to determine the overall frequency of major disagreements, defined as any change in diagnosis having a substantial impact on patient management. The authors’ review of 71,811 cases identified 457 (0.6 percent) major disagreements. The most frequent areas of disagreement were gastrointestinal (80 cases; 17.5 percent), lymph node (73; 16 percent), bone/soft tissue (47; 10.3 percent), and genitourinary (43; 9.4 percent). For a subset of 166 cases reviewed between July 1, 2009 and Dec. 31, 2010, followup data were available for 140 (84.3 percent). Treatment was affected by a changed diagnosis in 126 cases (90 percent), and prognosis was affected in 129 cases (92.1 percent). For 86 (51.8 percent) of the 166 cases, additional tissue was obtained. Revised diagnoses concurred with followup tissue diagnosis in 84.9 percent (73 cases) and differed from followup tissue diagnosis in 15.1 percent (13 cases). The authors concluded that outside case review of pathology materials for referred patients is valuable, and they suggest that it decreases the likelihood of diagnostic errors and provides better protection for patients.
Swapp RE, Aubry MC, Salomao DR, et al. Outside case review of surgical pathology for referred patients: the impact on patient care. Arch Pathol Lab Med. 2013;137:233–240.
Correspondence: Dr. John Cheville at cheville.john@mayo.edu
Reporting trends for right-sided hyperplastic and sessile serrated polyps
An audit of serrated polyps diagnosed over the four-year period of 2009 to 2012 was undertaken to ascertain the reporting trends for such polyps. All right-sided hyperplastic polyps proximal to the splenic flexure and all polyps designated as sessile serrated polyps (SSPs) were retrieved for the study period. Three pathologists blinded to the original diagnosis re-examined the slides. Recent American College of Gastroenterology guidelines for diagnosing SSP were used. No cases of SSP were diagnosed in 2009. In 2010, 32 right-sided cases were diagnosed, while 83 were confirmed in 2011 and 134 in 2012. The vast majority of these were right-sided. Twenty of 66 right-sided hyperplastic polyps were reclassified as SSP in 2009 (30 percent), 58 of 91 in 2010 (64 percent), 42 of 106 (40 percent) in 2011, and 69 of 206 in 2012 (33 percent). The authors concluded that an almost exponential increase in the diagnosis of SSP occurred over a four-year period. Reclassification of 30 percent to 64 percent of right-sided hyperplastic polyps as SSP over the four-year period suggests that greater awareness of the diagnostic criteria for SSP is required. Sessile serrated polyps are an important precursor lesion in the serrated pathway of colorectal cancer. Recognizing them is important for purposes of surveillance and determining therapeutic strategies.
Gill P, Wang LM, Bailey A, et al. Reporting trends of right-sided hyperplastic and sessile serrated polyps in a large teaching hospital over a 4-year period (2009–2012). J Clin Pathol. 2013; 66(8):655–658.
Correspondence: Runjan Chetty at runjan.chetty@gmail.com
Atypical leiomyomas of the uterus: a clinicopathologic study of 51 cases
Atypical leiomyoma is a well-described smooth muscle neoplasm of the uterus. Only one study has addressed long-term clinical followup in a large series, and little is known about the adequacy of treatment by myomectomy. For this study, the surgical pathology archives were searched for consecutive cases of uterine atypical leiomyoma from 1992 to 2003. Glass slides were reviewed to confirm diagnoses, and patient age, treatment modality, and clinical followup data were recorded. Fifty-one atypical leiomyomas with available glass slides and clinical followup data were identified. Thirty tumors exhibited diffuse, moderately to severely atypical cells; 21 showed atypical cells in a more focal or patchy distribution. Twelve had ischemic-type necrosis. By the highest count method, 37 cases were found to have no more than one mitotic figure per 10 high-power fields; 13 showed one to three mitotic figures per 10 high-power fields; and one was nearly entirely necrotic, precluding mitotic assessment. Among the 46 cases in which adjacent non-neoplastic tissue was well visualized, all were found to have pushing margins. The average tumor size was 6.8 cm (median, 6.5 cm; range, 0.7–14 cm). The average patient age was 42.5 years (median, 42 years; range, 21–72 years). In all cases, the initial diagnostic procedure was hysterectomy (34) or myomectomy (17). Average followup was 42 months (range, 0.3–121.8 months). Of those treated with hysterectomy, one had recurrent atypical leiomyoma in the retroperitoneum at 87.5 months, one died of other causes, and the remaining 32 (94 percent) were free of disease. Of the myomectomy group, 82 percent had no evidence of recurrent disease on followup; two had residual atypical leiomyoma in the subsequent hysterectomy specimen; and one underwent second myomectomy for atypical leiomyoma with two subsequent successful pregnancies. The authors concluded that atypical leiomyoma has a low rate of extrauterine, intra-abdominal recurrence (less than two percent), with a negligible risk for distant metastasis. Patients may be treated by myomectomy alone with successful pregnancy but should be monitored for local intrauterine residual/recurrent disease.
Ly A, Mills AM, McKenney JK, et al. Atypical leiomyomas of the uterus: a clinicopathologic study of 51 cases. Am J Surg Pathol. 2013;37(5):643–649.
Correspondence information not available.
Pathological diagnostic criterion of blood and lymphatic vessel invasion in colorectal cancer
The authors conducted a study with the intent of creating an objective pathological diagnostic system for blood and lymphatic vessel invasion. They reviewed 1,450 surgically resected colorectal cancer specimens from eight hospitals. The first phase of the study involved comparing the current practice of pathology assessment among eight hospitals. Then eight pathologists from these hospitals assessed hematoxylin-and-eosin–stained slides with or without histochemical/immunohistochemical staining, and concordance of blood and lymphatic vessel invasion (BLI) diagnosis was checked. Histological findings associated with BLI having good concordance were also reviewed. Based on these results, a framework for developing a diagnostic criterion was developed using the Delphi method. The new criterion was evaluated using 40 colorectal cancer specimens. The frequency of BLI diagnoses and the number of blocks obtained and stained to assess BLI varied among the eight hospitals. Concordance was low for BLI diagnosis and did not improve when histochemical/immunohistochemical staining was provided. All histological findings associated with BLI from hematoxylin-and-eosin staining had poor agreement. However, observation of elastica-stained internal elastic membrane covering more than half the circumference of the tumor cluster as well as the presence of D2-40–stained endothelial cells covering more than half the circumference of the tumor cluster showed high concordance. Based on this observation, the authors developed a framework for a pathological diagnostic criterion using the Delphi method. This criterion was found to be useful in improving concordance of BLI diagnoses. It may serve as the basis for creating a standardized procedure for pathological diagnosis.
Kojima M, Shimazaki H, Iwaya K, et al. Pathological diagnostic criterion of blood and lymphatic vessel invasion in colorectal cancer: a framework for developing an objective pathological diagnostic system using the Delphi method, from the Pathology Working Group of the Japanese Society for Cancer of the Colon and Rectum. J Clin Pathol. 2013;66(7):551–558.
Correspondence: Atsushi Ochiai at aochiai@east.ncc.go.jpn