Faculty Bibliography

Papillary thyroid carcinoma (PTC) is a common malignancy with multiple variants, some of which are rarely encountered in routine surgical pathology practice. PTC with exuberant nodular fasciitis-like stroma (PTC-NFS) or PTC with fibromatosis-like stroma (PTC-FMS) is one such variant. We report a case of PTC-NFS, a tumor characterized by an abundant stromal component with an intervening epithelial component with the typical morphologic features of conventional PTC. We review the literature on this rare variant, discuss the importance of a thorough search for epithelial components within any fibroproliferative lesion of the thyroid, and address the diagnostic difficulties created by the tumor's extensive stromal component.

INTRODUCTION: The purpose of the study was to determine predictors of recurrence for patients treated with neoadjuvant chemotherapy (NAC) and mastectomy according to the use of postmastectomy radiation therapy (PMRT). PATIENTS AND METHODS: An analysis of 161 clinically staged T1 to T3/N0 to N3 patients treated with NAC and mastectomy with and without PMRT at our institution from 2003 to 2010 was conducted. The Kaplan-Meier product limit method was used to estimate survival and time to recurrence rates and the log-rank test was used to compare groups. A Cox proportional hazard regression analysis was carried out for time to recurrence, radiation therapy, and their interaction in the model. RESULTS: The median follow-up period was 48 months and 18 patients developed a recurrence. The 5-year recurrence rate and overall survival was 16.1% (95% confidence interval [CI], 9.6%-26.3%) and 93.6% (95% CI, 88.2%-97.0%), respectively. Patients who underwent PMRT had a decreased risk of recurrence compared with patients who did not (hazard ratio [HR], 0.25; 95% CI, 0.097-0.661; P < .005). The 5-year disease-free survival (DFS) rate for those who received PMRT was 91.3% (95% CI, 82.8%-95.7%) and 64.8% (95% CI, 37.8%-82.4%) for those who did not (P = .0126). Among all clinicopathologic factors examined, pathologic T stage (ypT) and pathological N stage (ypN) significantly correlated with the risk of recurrence (P < .05). Patients with any pathological nodal disease had an increased risk of recurrence compared with patients who were pathologically node-negative (HR, 7.196; 95% CI, 2.05-25.264; P < .002). CONCLUSION: Patients treated with NAC and mastectomy, but without PMRT had a higher risk recurrence with increasing ypT and ypN stages. PMRT might increase DFS.

AIMS/OBJECTIVE:Atypical ductal hyperplasia (ADH) rarely arises in gynaecomastia. We set out to understand more clearly the clinical, histological and immunohistochemical features of ADH in this setting. METHODS AND RESULTS/RESULTS:Twenty-five cases of ADH arising in gynaecomastia, nine cases of ductal carcinoma in situ (DCIS) and 36 cases of gynaecomastia with usual ductal hyperplasia (UDH) were studied. Reviews of clinical, morphological and immunohistochemical findings were performed. The extent of cytokeratin 5/6 (CK5/6) luminal epithelial cell staining was assessed (0% = 0, < 10% = 1, 10-50% = 2 and > 50% = 3). Oestrogen receptor (ER) was evaluated using the H-scoring system. The average age of ADH patients was 35 years (range 14-78). ADH was bilateral in 20% and less frequent in active gynaecomastia (24%). ADH often showed a cribriform pattern (72%), with less nuclear variation/size and similar frequency of mitoses than UDH cells. CK5/6 luminal epithelial staining was decreased in ADH (68%) versus UDH (11%). ADH showed high ER expression compared to UDH (H score > 270 in 88% and 14%, respectively). CONCLUSIONS:ADH in gynaecomastia can be distinguished from UDH by morphological and immunohistochemical features. We also identified a subset of young patients (< 25 years) with extensive bilateral ADH. More studies are needed to characterize this patient subset more clearly.

Pleomorphic adenoma occurs commonly in the major salivary glands but is uncommonly encountered in the breast. In both of these locations, the tumor is typically grossly circumscribed and has a "mixed" histological appearance, being composed of myoepithelial and epithelial components amid a myxochondroid matrix. Herein, we report a case of pleomorphic adenoma of the breast which was preoperatively thought to represent a fibroadenoma on clinical and radiological grounds. It is the rarity of the tumor in the breast, rather than its histological appearance, that causes diagnostic difficulty.

BACKGROUND: Tumor microenvironment of metastasis (TMEM), consisting of direct contact between a macrophage, an endothelial cell, and a tumor cell, has been associated with metastasis in both rodent mammary tumors and human breast cancer. We prospectively examined the association between TMEM score and risk of distant metastasis and compared risk associated with TMEM score with that associated with IHC4. METHODS: We conducted a case-control study nested within a cohort of 3760 patients with invasive ductal breast carcinoma diagnosed between 1980 and 2000 and followed through 2010. Case patients were women who developed a subsequent distant metastasis; control subjects were matched (1:1) on age at and calendar year of primary diagnosis. TMEM was assessed by triple immunostain and IHC4 by standard methods; slides were read by pathologists blinded to outcome. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, adjusted for clinical variables. A Receiver Operating Characteristic analysis was performed, and the area under the curve was estimated. All statistical tests were two-sided. RESULTS: TMEM score was associated with increased risk of distant metastasis in estrogen receptor (ER)(+)/human epidermal growth factor receptor (HER2)(-) tumors (multivariable OR high vs low tertile = 2.70; 95% CI = 1.39 to 5.26; P trend = .004), whereas IHC4 score had a borderline positive association (OR10 unit increase = 1.06; 95% CI = 1.00 to 1.13); the association for TMEM score persisted after adjustment for IHC4 score. The area under the curve for TMEM, adjusted for clinical variables, was 0.78. Neither TMEM score nor IHC4 score was independently associated with metastatic risk overall or in the triple negative or HER2(+) subgroups. CONCLUSIONS: TMEM score predicted risk of distant metastasis in ER(+)/HER2(-) breast cancer independently of IHC4 score and classical clinicopathologic features.

The abdominal mesenteries are important peritoneal structures that give rise to a wide spectrum of abnormalities, including solid mesenteric masses. Despite similarities in appearance, solid masses in the mesentery may have diverse etiologies, ranging from benign to highly malignant. While metastases are the most common cause of solid masses in the mesentery, other less common conditions are also important diagnostic considerations. This article reviews four pathologic entities (sclerosing mesenteritis, carcinoid tumors, desmoids tumors, and gastrointestinal stromal tumors) that may be manifested on abdominal imaging examinations by one or more mesenteric masses. These four pathologic entities are used to present a systematic approach to the radiographic characterization of solid mesenteric masses based on the morphology of the lesions, locoregional effects, and distant findings on various abdominal imaging examinations.