Faculty Bibliography

OBJECTIVES/OBJECTIVE:Stereotactic core needle biopsy (SCNB) is used in the diagnostic assessment of suspicious mammographic calcifications to rule out breast ductal carcinoma in situ (DCIS). With advances in imaging technology and increased biopsy tissue volume, the detection rate of calcifications and DCIS in SCNB is unclear. METHODS:This retrospective study included 916 consecutive SCNBs for calcifications performed on 893 patients in a 2-year period. RESULTS:We found the cancer detection rate was 27.1% (DCIS, 23.7%; invasive, 3.4%). The detection rate for calcifications was 74.8% with the standard 3 levels. Additional leveling of calcification-negative cases further increased the detection of both calcifications (to 99.4% of cases) and DCIS (to 32.9% of cases). Lobular neoplasia (LN) was diagnosed in 41 cases. Twenty-five (61.0%) cases of LN were incidental without associated calcification. Of 32 invasive carcinomas detected on SCNB, 87.5% were T1a or less, and calcifications were associated with atypical ductal hyperplasia/DCIS or LCIS. The common benign lesions associated with calcifications were fibrocystic change (32.5%), fibroadenomatous change (30.2%), and columnar cell change and hyperplasia (8.2%). CONCLUSIONS:We determined the up-to-date detection rates of calcification and DCIS in SCNB, as well as the common benign and malignant breast lesions associated with calcifications. Additional levels significantly increase the detection rate when standard levels show only stromal or scant/absent calcifications. Lobular neoplasia is often an incidental finding in SCNB for calcifications. When calcifications are present with LN, they are commonly florid, pleomorphic LCIS, or with concurrent invasive carcinoma.

Mismatch repair (MMR) alterations are important prognostic and predictive biomarkers in a variety of cancer subtypes, including colorectal and endometrial. However, in breast cancer (BC), the distinction and clinical significance of MMR are largely unknown. This may be due in part to the fact that genetic alterations in MMR genes are rare and only seen to occur in around 3% of BCs. In the present study, we analyzed TCGA data using a multi-sample protein-protein interaction (PPI) analysis tool, Proteinarium, and showed a distinct separation between specific MMR-deficient and -intact networks in a cohort of 994 BC patients. In the PPI networks specific to MMR deficiency, highly connected clusters of histone genes were identified. We also found the distribution of MMR-deficient BC to be more prevalent in HER2-enriched and triple-negative (TN) BC subtypes compared to luminal BCs. We recommend defining MMR-deficient BC by next-generation sequencing (NGS) when any somatic mutation is detected in one of the seven MMR genes.

Genomic alterations (GA) in NF2 tumor-suppressor gene have been associated with aggressive behavior in kidney tumors. We used comprehensive genomic profiling (CGP) to evaluate the frequencies of NF2 GA in histologic subtypes of kidney tumors and co-occurring GA in other genes and biomarkers. Advanced kidney tumors included 1875 clear cell (ccRCC), 405 papillary (pRCC), 108 chromophobe (chRCC), 171 sarcomatoid (sRCC), 61 collecting duct (cdRCC), 49 medullary (mRCC), 134 unclassified (uRCC), 906 urothelial carcinoma of renal pelvis (UC), and 147 Wilms tumors underwent hybrid-capture based CGP to evaluate all classes of GA. 192 (4.9%) of kidney tumors featured NF2 GA which were predominantly structural variant mutations (89%), followed by copy number alterations (9%). Gender and age were similar between NF2-mutant (NF2mut) and NF2-wild type (NF2wt) cohorts with male preponderance. NF2 GA frequency was highest in cdRCC (30%), sRCC (21%), uRCC (15%), and pRCC (12%) while lowest in ccRCC (3%), UC (3%) Wilms tumor (1%), and chRCC (0%). NF2 mutational status was associated with loss of Ch 22 (P < .001). NF2mut RCC harbored co-occurring GA including CDKN2A, CDKN2B, SETD2, and BAP1. VHL, PBRM1, PTEN, and FGFR3 GA were significantly more frequent in NF2wt than in NF2mut tumors. MTOR pathway GAs were uncommon in NF2mut tumors. No NF2 mutated RCC featured MSI-high or high TMB. sRCC was associated with high PD-L1 expression. PD-L1 SP142 tumoral (P = .04) and immune cells (P = .013) were more frequent in NF2mut as compared to NF2wt group. Among histologic subtypes of RCC, cdRCC, sRCC, pRCC, and uRCC are enriched in NF2 GA. Co-occurrent GA in CDKN2A/B, SETD2, and BAP1 may represent potential therapeutic targets. Higher level of PD-L1 expression in NF2mut cohort suggests that these tumors might be sensitive to immune checkpoint inhibitor therapies.

In cases of growth of FA on imaging, core needle biopsies (CNB) are often performed to rule out phyllodes tumor (PT). We aim to focus on "growing FAs" and to identify clinical and histopathologic features that are likely to predict a PT on excision. Thirty-four FAs with radiologic documentation of growth were included. Various clinical and pathological features such as age, body mass index (BMI), lesion size, and growth rate were recorded. On excision, 17 cases (50 %) were FAs, whereas 16 (47 %) were re-classified as benign PT despite only 19 % being suspicious for PT on CNB. PT patients were older (mean age 42.6) than those with FAs (mean age 28.2), p = 0.0002. All false negative cases demonstrated intracanalicular growth. Mitotic rate was the most significant histologic feature in PT on excision compared to others, such as lesion circumscription and stromal cellularity. Recognition and careful counting of mitotic rate, especially with intracanalicular patterns in growing FAs, can potentially prevent missing a PT on CNB. In patients with "growing FAs" who are ≥40 years of age, excision may be recommended due to the high likelihood of PT diagnosis on excision and high false negative rate on CNB.

Laryngeal malignancy encompasses about 1% of all cancers. Chondrosarcoma in the head and neck region represents about 0.1% of head and neck malignancies. Typical presenting symptoms relate to the anatomical location of these tumours and include dysphonia, inspiratory stridor, dysphagia, odynophagia or a neck mass. Benign and malignant cartilaginous cancers of the larynx have been described, and preoperative diagnosis can be difficult. Our report highlights the surgical management of a male patient in his 50s with chondrosarcoma of the thyroid cartilage.

Triple-negative breast cancer (TNBC) is a heterogenous group of tumors. Most TNBCs are high-grade aggressive tumors, but a minority of TNBCs are not high grade, with relatively indolent behavior and specific morphologic and molecular features. We performed a clinicopathologic and molecular assessment of 18 non-high-grade TNBCs with apocrine and/or histiocytoid features. All were grade I or II with low Ki-67 (≤20%). Thirteen (72%) showed apocrine features, and 5 (28%) showed histiocytoid and lobular features. In all, 17/18 expressed the androgen receptor, and 13/13 expressed gross cystic disease fluid protein 15. Four (22.2%) patients were treated with neoadjuvant chemotherapy, but none achieved a pathologic complete response. In all, 2/18 patients (11%) had lymph node metastasis at the time of surgery. None of the cases had a recurrence or disease-specific death, with an average follow-up time of 38 months. Thirteen cases were profiled by targeted capture-based next-generation DNA sequencing. Genomic alterations (GAs) were most significant for PI3K-PKB/Akt pathway (69%) genes, including PIK3R1 (23%), PIK3CA (38%), and PTEN (23%), and RTK-RAS pathway (62%) including FGFR4 (46%) and ERBB2 (15%). TP53 GA was seen in only 31% of patients. Our findings support those on high-grade TNBCs with apocrine and/or histiocytoid features as a clinicopathologic and genetically distinct subgroup of TNBC. They can be defined by features including tubule formation, rare mitosis, low Ki-67 (≤20%), triple-negative status, expression of androgen receptor and/or gross cystic disease fluid protein 15, and GA in the PI3K-PKB/Akt and/or RTK-RAS pathway. These tumors are not sensitive to chemotherapy but have favorable clinical behavior. Tumor subtype definitions are the first step to implementing future trial designs to select these patients.

Ultrasound (US) guided core needle biopsy (CNB) for mass lesions resulting in a diagnosis of ductal carcinoma in situ (DCIS) is often considered radiologically discordant and generates surgical planning difficulty. One hundred cases of US-guided CNB for mass lesions diagnosed as DCIS were collected from 2013 to 2021. Histological features were reviewed and correlated with radiology and surgical excision findings. Thirty (30%) were high-grade (HG), and seventy (70%) were low- to intermediate-grade. Seventy-one (71%) cases had a histological correlate of a mass-forming lesion, including 26 (26%) were associated with benign mass-forming lesions (category 1) such as papilloma, complex sclerosing lesion/radial scar, fibroadenoma, sclerosing adenosis, and ruptured cyst; 23 (23%) were HG with solid pattern, comedo necrosis, and stromal desmoplasia (category 2); and 22 (22%) had predominantly papillary architecture (category 3). Twenty-nine (29%) were discordant with no histologic correlate of a mass lesion (category 4). Follow-up excisions were available in 79 cases. Invasive carcinoma was identified in 14 cases (18%), of which 8 were from the radiologically discordant category (35%), 3 (17%) associated with HG DCIS with desmoplasia, 2 (10%) associated with benign mass lesion and 1(5%) was predominantly papillary architecture. US-guided CNB for mass-forming lesions with a DCIS diagnosis on CNB can be grouped into four categories. Radiology-pathology correlation is essential. This categorization emphasized rad-path correlation and had a clear difference in upgrade rate on follow-up excision. Rad-path discordant biopsy cases were more likely to be associated with a missed invasive carcinoma (p < 0.05).

Whether sentinel lymph node biopsy (SLNB) should be performed in patients with microinvasive breast cancer (MIBC) has been a matter of debate over the last decade. MIBC has a favorable prognosis and while metastasis to the axilla is rare, it can impact treatment recommendations. In this study we evaluated clinical and histological features in both MIBC and background DCIS including ER, PR, and HER-2, number of foci of MIBC, the extent of the DCIS, nuclear grade, presence of comedo necrosis, as well as surgical procedures, adjuvant treatment and follow up to identify variables which predict disease free survival (DFS), as well as the factors which influence clinical decision making. Our study included 72 MIBC patients with a mean patient follow-up time of 55 months. Three patients with MIBC had recurrence, and two deceased, leaving five patients in total with poor long-term outcomes and a DFS rate of 93.1%. Performing mastectomy, high nuclear grade, and negativity for ER and HER-2 were found to be associated with the use of SLNB, although none of these variables were found to be associated with DFS. One positive lymph node case was discovered following SLNB in our study. This suggests the use of SLNB may provide diagnostic information to some patients, although these are the anomalies. When comparing patients who had undergone SLNB to those which had not there was no difference in DFS. Certainly, the use of SLNB in MIBC is quite the conundrum. It is important to acknowledge that surgical complications have been reported, and traditional metrics used for risk assessment in invasive breast cancer may not hold true in the setting of microinvasion.

A 60-year-old female presented with asymptomatic failing mandibular dental implants. Computed tomography (CT) showed a partially calcified, hypointense lesion within the soft tissues, measuring 1.3 x 0.8 x 1.0 cm along the buccal cortex. Incisional biopsy demonstrated a basaloid type of tumor composed of sheets of cells with plump ovoid nuclei, distinct nucleoli, and scant eosinophilic cytoplasm. Mitoses were present, averaging about 2 per 10 high power fields with scattered individual apoptotic cells. Numerous laminated calcified bodies (Liesegang rings) were observed with confluence of these bodies to form larger foci of dystrophic mineralization. These features clearly established the malignant nature of this tumor. Immunohistochemically, the tumor was positive for synaptophysin, focally positivity for CAM 5.2 and had a Ki-67 proliferation index of approximately 25%. This is the first report of a tumor with features of a malignant variant of calcifying epithelial odontogenic tumor and neuroendocrine differentiation.

Plasma cell myeloma (PCM) is defined as a clonal disease of terminally differentiated plasma cells that secrete immunoglobulin. The biologic underpinnings of IgA-type multiple myeloma's (IgAMM) aggressive nature, including its increased morbidity and mortality, have not been elucidated. We describe the clinical, phenotypic, and cytogenetic characteristics of IgA-MM. Flow-cytometry analysis was performed to phenotype clonal plasma cell populations, and interface with fluorescent in situ hybridization (iFISH) to exploit cytogenetics to determine risk stratification; 68.1% of cases were of intermediate or high risk. On flow cytometry, samples from our IgA-PCM cohort revealed less frequent CD56 expression when compared to samples with other PCM subtypes. Our study demonstrated lower frequency of CD56 expression (52.8%). We hypothesize that loss of CD56 may play a significant role in the aggressive behavior of IgA-PCM due to the loss of cell-to-cell adhesion resulting in a higher propensity for extramedullary presentation.