Non-sclerosing (T-cell) and sclerosing (B-cell) lymphocytic lobulitis in diagnostic breast biopsies: Clinical, imaging, and pathologic features.

Lymphocytic lobulitis (LL) is characterized by prominent lymphocytic infiltrates centered on lobules. Sclerosing lymphocytic lobulitis (SCLL) associated with diabetes mellitus (DM) or autoimmune disease (AI) was the first type to be described. Subsequently, non-sclerosing LL (NSCLL) was reported as an incidental finding in prophylactic mastectomies due to high risk germline mutations or a family history of breast cancer. The two types of LL were distinguished by stromal features and a predominant population of B-cells in the former and T-cells in the latter. In this study, 8 cases of NSCLL detected clinically or by screening were compared to 44 cases of SCLL. One case of NSCLL presented as a palpable mass, 2 as masses on screening, and 5 as MRI enhancement. In contrast, 80% of SCLL cases presented as palpable masses. Half the cases of NSCLL were associated with a BRCA1 or 2 mutation compared to 1 case of SCLL (2%). Three additional cases of NSCLL were associated with a strong family and/or personal history of breast cancer. Almost half (52%) of SCLL cases were associated with DM or AI, but only 25% of NSCLL. Immunoperoxidase studies confirmed a predominance of T-cells in NSCLL and B-cells in SCLL associated with DM or AI. It is important for pathologists to be aware of this new observation that NSCLL can be detected as a palpable mass or an imaging finding in diagnostic biopsies, as its presence can be indicative of a significant risk for breast cancer.

Identification of Glandular (Acinar)/Tubule Formation in Invasive Carcinoma of the Breast: A Study to Determine Concordance Using the World Health Organization Definition.

CONTEXT.­: The Nottingham Grading System (NGS) developed by Elston and Ellis is used to grade invasive breast cancer (IBC). Glandular (acinar)/tubule formation is a component of NGS. OBJECTIVE.­: To investigate the ability of pathologists to identify individual structures that should be classified as glandular (acinar)/tubule formation. DESIGN.­: A total of 58 hematoxylin-eosin photographic images of IBC with 1 structure circled were classified as tubules (41 cases) or nontubules (17 cases) by Professor Ellis. Images were sent as a PowerPoint (Microsoft) file to breast pathologists, who were provided with the World Health Organization definition of a tubule and asked to determine if a circled structure represented a tubule. RESULTS.­: Among 35 pathologists, the κ statistic for assessing agreement in evaluating the 58 images was 0.324 (95% CI, 0.314-0.335). The median concordance rate between a participating pathologist and Professor Ellis was 94.1% for evaluating 17 nontubule cases and 53.7% for 41 tubule cases. A total of 41% of the tubule cases were classified correctly by less than 50% of pathologists. Structures classified as tubules by Professor Ellis but often not recognized as tubules by pathologists included glands with complex architecture, mucinous carcinoma, and the "inverted tubule" pattern of micropapillary carcinoma. A total of 80% of participants reported that they did not have clarity on what represented a tubule. CONCLUSIONS.­: We identified structures that should be included as tubules but that were not readily identified by pathologists. Greater concordance for identification of tubules might be obtained by providing more detailed images and descriptions of the types of structures included as tubules.

Tumor bed extending to margins in breast cancer specimens after neoadjuvant chemotherapy: Incidence and clinical significance.

BACKGROUND: Pathologic examination of post-neoadjuvant chemotherapy (NAC) breast surgical specimens includes assessment of margins. It has been recommended that tumor bed (TB) changes extending to margins should be documented; however, its' incidence and clinical significance have not yet been established. The aim of our study was to gather prognostic data on this histological finding. DESIGN: We retrospectively identified all cases where TB was reported at margin. Cases where margins were also positive for invasive carcinoma or DCIS were excluded. RESULTS: From 2016 to 2019, 115 cases of NAC treated breast cancers were identified with 21 having at least one margin positive for TB after initial surgery (incidence of 18.3 %). Five cases were estrogen receptor (ER)-/HER2-, 9 were HER2+ and 7 were ER+/HER2-. Nineteen patients underwent partial mastectomy and 2 underwent total mastectomy. Nine patients had a pathological complete response (pCR).Ten cases had more than one positive margin for TB. None of the 21 patients underwent a second surgery for margin re-excision. Twenty patients received adjuvant therapy. With an average follow-up of 28.1 months, there has been one local recurrence. Four other patients developed metastatic disease, one of which died of the disease. The rates of locoregional and distant recurrence and mortality were statistically similar to those from patients whose margins were negative for TB. CONCLUSIONS: Our results suggest low risk of local recurrence when a positive margin for TB is not re-excised. Further data and follow-up will be needed to confirm the adequacy of conservative management in this setting.

Sebaceous Epithelial-Myoepithelial Carcinoma With Aggressive Behavior and Evidence of Preexisting Pleomorphic Adenoma.

Epithelial-myoepithelial carcinoma (EMCA) is a rare low-grade carcinoma of the salivary glands with multiple morphological variants. One such variant, sebaceous EMCA (SEMCA), has been reported in the literature. Distinguishing it from other tumors such as sebaceous carcinoma is crucial, as SEMCA typically behaves more indolently. We present a case of a SEMCA in the right parotid of a 71-year-old man that shows features of aggressive behavior such as facial nerve invasion and extraparenchymal extension. Also, we report evidence of preexisting pleomorphic adenoma within this tumor.