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.

Distinguishing papillary endothelial hyperplasia and angiosarcoma on core needle biopsy of the breast: The importance of clinical and radiologic correlation.

Papillary endothelial hyperplasia (PEH) is a rare non-neoplastic exuberant organizing hematoma that can closely mimic angiosarcoma due to a resemblance to malignant anastomosing blood vessels. It could be particularly difficult to distinguish PEH from angiosarcoma in breast core needle biopsies. We identified all cases of these lesions diagnosed on core needle biopsy in order to identify clinical, radiologic, and pathologic features that could prove helpful to arrive at the correct diagnosis. Four cases of PEH and 4 cases of angiosarcoma were identified. The mean age at diagnosis was 62 for PEH and 33 for primary angiosarcoma. All cases of PEH formed small masses with circumscribed or lobulated margins by imaging (mean size 0.9 cm). In 3 cases, the masses were difficult or impossible to identify after the biopsy. Angiosarcomas presented as larger masses with ill-defined margins (mean size 2.8 cm) that were unchanged in size after biopsy. PEH was surrounded by adipose tissue, whereas angiosarcoma invaded into fibrous stroma and involved lobules. The pseudopapillary structures of PEH were composed mainly of collagen, and thus, additional histologic stains for fibrin were not helpful for diagnosis. The 4 patients with PEH received no further treatment and are alive and disease-free at 2-11 years of follow-up. In contrast, the patients with angiosarcoma underwent mastectomy and chemotherapy or radiation therapy. Two of the patients with angiosarcoma died 3 years after diagnosis and the other 2 patients are alive without disease at 5 and 6 years. Therefore, distinguishing PEH and angiosarcoma is essential for appropriate management. This is the first series to compare these lesions on core needle biopsy and the first to note important clinical, imaging, and histologic differences that aid in making a diagnosis of PEH with confidence on breast core needle biopsy.

Uterine Leiomyoma With Osteoclast-like Giant Cells.

Numerous histologic variants of uterine leiomyomas have been described. The main interest in recognizing these variants is differentiating them from leiomyosarcoma. Osteoclast-like giant cells (OLGC) have been described in association with leiomyosarcoma but to our knowledge, never with leiomyoma. We here report the case of a 58-year-old woman who underwent an elective total hysterectomy with bilateral salpingo-oophorectomy and bilateral pelvic lymphadenectomy for endometrial atypical complex hyperplasia. Multiple typical uterine leiomyoma were identified. One of them showed numerous OLGC admixed with fascicules of bland smooth muscle cells. No atypical features were identified in multiple sections of this otherwise classic uterine leiomyoma. The OLGC showed strong positivity for CD68. The patient, on follow-up, did not show any evidence of recurrent or metastatic disease. This unusual finding expands the morphologic spectrum of uterine leiomyomas. When confronted with a uterine smooth muscle cell tumor with an OLGC component, it is important to search for atypical features diagnostic of leiomyosarcoma.

Transformation of a primitive myxoid mesenchymal tumor of infancy to an undifferentiated sarcoma: a first reported case.

An 8-month-old girl underwent surgical resection of a cervical mass with histologic diagnosis of a primitive myxoid mesenchymal tumor of infancy (PMMTI). More than 5 years after the initial surgical intervention, the tumor recurred locally, with numerous distant metastases. The histologic morphology of this tumor was compatible with a diagnosis of an undifferentiated high-grade sarcoma. PMMTI is a recently described poorly differentiated fibroblastic soft-tissue tumor of infancy, of at least borderline biological behavior, characterized by local recurrence and a potential to metastasize. We present here the first case of a transformation of a PMMTI into an undifferentiated high-grade sarcoma.

Nodular Regenerative Hyperplasia: Expression Pattern of Glutamine Synthetase and a Potential Role for Hepatic Progenitor Cells.

Nodular regenerative hyperplasia (NRH) is one of the most frequent causes of noncirrhotic intrahepatic hypertension, but is a difficult histologic diagnosis. The expression of glutamine synthetase (GS) and cytokeratin 7 (CK7) has been reported to be increased in other regenerative/vascular conditions, while CK7 and BerEP4 are also markers of hepatic progenitor cells. The aims of this study were to investigate the use of GS, CK7, and BerEP4 as the potential markers for NRH. This is a retrospective case series of NRH at Centre Hospitalier de l'Universite de Montreal between 1993 and 2013. Normal liver from partial hepatectomies for tumors were used as controls. GS, CK7, CK19, and BerEP4 immunohistochemical stains were performed on all specimens. Immunohistochemical staining patterns were scored from 0 to 3+. NRH was identified in 46 samples obtained from 26 patients. Liver chemistry profile was cholestatic in 45% of the patients. In 93% of the NRH cases, there was abnormal zone 2 expression of GS. Weak panacinar GS staining was seen in all the NRH cases. Aberrant CK7 expression was present in all cases of NRH, but were not associated with cholestasis. BerEP4 was overexpressed in 47% of the NRH cases (P<0.05); all cases with diffuse BerEP4 staining also showed extensive CK7 expression (P<0.01). NRH showed increased immunohistochemical GS staining that may support its morphologic diagnosis. Our findings suggest that there is an activation of hepatic progenitor cells in NRH.

Hematologic Malignancies of the Breast: A Contemporary Series Investigating Incidence, Presentation, Accuracy of Diagnosis on Core Needle Biopsy, and Hormone Receptor Expression.

BACKGROUND: Distinguishing breast hematologic malignancies in core needle biopsies from other entities can be challenging. Misclassification as a breast carcinoma could result in inappropriate treatment. The aim of this study was to characterize the types, incidence, and helpful diagnostic features of hematologic malignancies of the breast. DESIGN: All hematologic malignancies of the breast diagnosed at our institution from 2004 to 2017 were identified. Clinical notes, imaging, and slides were reviewed. Immunohistochemical analysis of estrogen receptor α (ERα), estrogen receptor ß (ERß), and androgen receptor (AR) was performed when tissue was available. RESULTS: In all, 43 hematologic malignancies from biopsies of 37 women and 6 men were identified. Core needle biopsies (35 or 81%) were more common than excisions (8 or 19%). For 14 patients (40%), the core biopsy was the first diagnosis of a hematologic malignancy. Diagnoses included 37 lymphomas (7 primary), 4 leukemias, and 2 myelomas. There was 1 misdiagnosis of carcinoma. Low positivity for hormone receptors was observed in a minority of lymphomas. A definitive diagnosis of hematologic malignancy was made in 31 (89%) of the core needle biopsies. Only 3 patients undergoing core biopsy required excision for diagnosis. CONCLUSIONS: Most of the hematologic malignancies of the breast are currently diagnosed on core needle biopsy and 40% of patients do not have a prior history. To avoid errors, pathologists need to be aware of diagnostic features and morphologic mimics. A hematologic malignancy should be considered if tumor cells are discohesive, carcinoma in situ is absent, and hormone expression is low or absent.

A Unique Morphological Phenotype in Chemoresistant Triple-Negative Breast Cancer Reveals Metabolic Reprogramming and PLIN4 Expression as a Molecular Vulnerability.

The major obstacle in successfully treating triple-negative breast cancer (TNBC) is resistance to cytotoxic chemotherapy, the mainstay of treatment in this disease. Previous preclinical models of chemoresistance in TNBC have suffered from a lack of clinical relevance. Using a single high dose chemotherapy treatment, we developed a novel MDA-MB-436 cell-based model of chemoresistance characterized by a unique and complex morphologic phenotype, which consists of polyploid giant cancer cells giving rise to neuron-like mononuclear daughter cells filled with smaller but functional mitochondria and numerous lipid droplets. This resistant phenotype is associated with metabolic reprogramming with a shift to a greater dependence on fatty acids and oxidative phosphorylation. We validated both the molecular and histologic features of this model in a clinical cohort of primary chemoresistant TNBCs and identified several metabolic vulnerabilities including a dependence on PLIN4, a perilipin coating the observed lipid droplets, expressed both in the TNBC-resistant cells and clinical chemoresistant tumors treated with neoadjuvant doxorubicin-based chemotherapy. These findings thus reveal a novel mechanism of chemotherapy resistance that has therapeutic implications in the treatment of drug-resistant cancer. IMPLICATIONS: These findings underlie the importance of a novel morphologic-metabolic phenotype associated with chemotherapy resistance in TNBC, and bring to light novel therapeutic targets resulting from vulnerabilities in this phenotype, including the expression of PLIN4 essential for stabilizing lipid droplets in resistant cells.

Arterial trauma during central venous catheter insertion: Case series, review and proposed algorithm.

BACKGROUND: Percutaneous catheterization is a frequently-used technique to gain access to the central venous circulation. Inadvertent arterial puncture is often without consequence, but can lead to devastating complications if it goes unrecognized and a large-bore dilator or catheter is inserted. The present study reviews our experience with these complications and the literature to determine the safest way to manage catheter-related cervicothoracic arterial injury (CRCAI). METHODS: We retrospectively identified all cases of iatrogenic carotid or subclavian injury following central venous catheterization at three large institutions in Montreal. We reviewed the French and English literature published from 1980 to 2006, in PubMed, and selected studies with the following criteria: arterial misplacement of a large-caliber cannula (>/=7F), adult patients (>18 years old), description of the method for managing arterial trauma, reference population (denominator) to estimate the success rate of the therapeutic option chosen. A consensus panel of vascular surgeons, anesthetists and intensivists reviewed this information and proposed a treatment algorithm. RESULTS: Thirteen patients were treated for CRCAI in participating institutions. Five of them underwent immediate catheter removal and compression, and all had severe complications resulting in major stroke and death in one patient, with the other four undergoing further intervention for a false aneurysm or massive bleeding. The remaining eight patients were treated by immediate open repair (six) or through an endovascular approach (two) for subclavian artery trauma without complications. Five articles met all our inclusion criteria, for a total of 30 patients with iatrogenic arterial cannulation: 17 were treated by immediate catheter removal and direct external pressure; eight (47%) had major complications requiring further interventions; and two died. The remaining 13 patients submitted to immediate surgical exploration, catheter removal and artery repair under direct vision, without any complications (47% vs 0%, P = .004). CONCLUSION: During central venous placement, prevention of arterial puncture and cannulation is essential to minimize serious sequelae. If arterial trauma with a large-caliber catheter occurs, prompt surgical or endovascular treatment seems to be the safest approach. The pull/pressure technique is associated with a significant risk of hematoma, airway obstruction, stroke, and false aneurysm. Endovascular treatment appears to be safe for the management of arterial injuries that are difficult to expose surgically, such as those below or behind the clavicle. After arterial repair, prompt neurological evaluation should be performed, even if it requires postponing elective intervention. Imaging is suggested to exclude arterial complications, especially if arterial trauma site was not examined and repaired.

Pure Intralymphatic Invasion in the Absence of Stromal Invasion After Neoadjuvant Therapy: A Rare Pattern of Residual Breast Carcinoma.

Rarely is intralymphatic/lymph-vascular invasion (LVI) the only residual disease in the breast after neoadjuvant chemotherapy. Only 12 patients have been reported in 2 prior studies. Prognosis was poor, with only 2 patients remaining alive and disease-free. The purpose of this study was to gather more data on this pattern of residual disease. Cases in which LVI was the only residual disease in the breast were retrospectively identified. Eighteen cases were identified including 10 of 669 (1.5%) consecutive surgical cases between 2003 and 2015. The mean tumor size was 3.4 cm. Seven cancers were negative for estrogen receptor and HER2, 8 were HER2 positive, and 3 were estrogen receptor positive and HER2 negative. In 15 cases, lymph nodes were either suspicious by imaging or proven positive by biopsy. After neoadjuvant chemotherapy, 9 patients were node negative, 7 were node positive, and 2 had isolated tumor cells. Mean follow-up was 63.8 months (7 to 138 mo). Two deaths occurred in patients with positive nodes. One death occurred and 2 patients are alive with metastatic disease in the node-negative group. The remaining 13 patients are alive without disease. The outcome associated with residual LVI might not be as dismal as previously reported. Although the better outcome may be due to stage at presentation or the type of chemotherapy, it is difficult to compare the cohorts of the 3 studies. However, the death of 3 of 13 node-negative patients over the 3 studies supports not classifying residual LVI as a pathologic complete response.