Atypia

OBJECTIVES: Few cytologically indeterminate thyroid fine-needle aspirations (FNAs) harbor BRAF V600E. Here, we assess interobserver agreement for The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) category III (atypia of undetermined significance [AUS]) FNAs harboring BRAF V600E and contrast their features with those harboring non-BRAF V600E alterations, with attention to cytopathology experience. METHODS: Seven reviewers evaluated 5 AUS thyroid FNAs harboring BRAF V600E...

AIMS: Low-grade myofibroblastic sarcoma (LGMS) is a rarely metastasizing myofibroblastic tumour mostly affecting extremities and the head and neck of adults. Histologically, it shows long infiltrative fascicles of spindle cells with moderate nuclear atypia. By immunohistochemistry, it stains positive for smooth muscle actin (SMA) and sometimes for desmin. To date, no recurrent genetic abnormalities have been described. Ubiquitin-specific peptidase 6 (USP6) gene rearrangement is typically found in some benign bone and soft-tissue tumours including nodular fasciitis (NF), among others...

Differentiated vulvar intraepithelial neoplasia (d-VIN) is an HPV-independent precursor to vulvar squamous cell carcinoma. The histology of d-VIN lesions is difficult to differentiate from that of non-neoplastic epithelial disorders, especially lichen sclerosus (LS). The authors present a case of LS, where relying on histopathology alone could have led to misdiagnosis. The patient was a 17-year-old female patient with clinical features of vulvar dermatitis and LS for 2 years. She was counseled to apply clobetasol 0...

Uterine smooth muscle tumors are a heterogeneous group of mesenchymal neoplasms with multiple histologic variants and distinct biological behaviors. Pathologic classification (benign, uncertain malignant potential, malignant) relies on the evaluation of mitotic index, necrosis, and degree of cytologic atypia, with different thresholds based on each subtype. Immunohistochemistry and other ancillary studies may be necessary to establish the diagnosis in a subset of cases, given the morphologic overlap with other mesenchymal neoplasms, including low-grade and high-grade endometrial stromal tumors, inflammatory myofibroblastic tumors, and PEComa...

Anaplastic lymphoma kinase (ALK) gene fusions are rare in papillary thyroid carcinoma (PTC) but may serve as a therapeutic target. This study aims to evaluate the preoperative cytologic findings and clinicopathologic features of a series of eight ALK-rearranged PTCs from our pathology archives and consultations. All cases were confirmed by ALK D5F3 immunohistochemistry and six with additional targeted RNA-based next-generation sequencing (NGS). The original fine-needle aspiration (FNA) cytology diagnosis included the Bethesda System (TBS) category II in three (37...

INTRODUCTION: Serous fluids offer crucial diagnostic insights, but inconsistent analysis hampers reporting quality, especially in indeterminate (ID) categories like atypia of undetermined significance (AUS) and suspicious for malignancy (SFM). The 2020 International System for reporting Serous Fluid Cytopathology (TIS) aims to standardize communication and reduce reporting disparities. This study evaluates TIS's role in AUS and SFM categories within our institution. MATERIAL AND METHODS: A 4-year retrospective search of cytopathology reports from December 2015 to December 2019 for AUS and SFM diagnoses in pleural, ascitic, pericardial fluids, and peritoneal washings was performed and results reclassified using TIS definitions...

BACKGROUND: The advances of minimally invasive endoscopy-guided procedures that usually yield limited diagnostic material changed pancreaticobiliary cytopathology into one of the most challenging areas of Cytopathology given the abundance of differential diagnoses to be considered when dealing with limited specimens. SUMMARY: We describes a few challenging, examples of potential pitfalls in pancreatobiliary cytopathology evaluation collected from a busy academic hospital (tertiary) center...

Uterine inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms of uncertain malignant potential. Aside from the recently described risk stratification score, which has not been validated by other studies, and rare reports of aberrant p16 expression in malignant tumors, there are no criteria to reliably predict behavior. Herein, we evaluated the clinicopathologic features and p16 expression patterns in 30 IMTs, with genomic profiling performed in a subset (13 malignant, 3 benign). Fifteen patients had malignant IMTs, defined by extrauterine disease at diagnosis (n=5) or recurrence (n=10; median: 24 mo)...

Adrenal cysts lined by thyroid follicular epithelium are rare, with only 14 reported cases of "ectopic thyroid tissue" to date. While the primary consideration for differential diagnosis is thyroid carcinoma metastasis, exclusion of metastases is determined based on the absence of a primary thyroid lesion, serological euthyroidism, lack of thyroglobulin elevation, and absence of epithelial atypia. Herein, we report 2 cases of adrenal cysts lined by thyroid follicular epithelium. Case 1 was a 60-year-old woman with a right adrenal cyst...

Diffuse tenosynovial giant cell tumor (D-TGCT), previously known as pigmented villonodular synovitis (PVNS), is a benign, aggressive, and distracting proliferative synovial lesion. D-TGCT is commonly seen in large joints such as the knee and hip. We present the case of a 57-year-old female who initially presented with swelling on the left midfoot that increased over four years. Clinically, a ganglion was suspected on the left midfoot and an MRI showed a heterogeneous lobulated soft tissue mass on the superior aspect of the tarsal midfoot measuring 5...

BACKGROUND: Prognostic indicators for equine multinodular pulmonary fibrosis (EMPF), an interstitial fibrosing lung disease, are poorly described. HYPOTHESIS/OBJECTIVES: Describe diagnostic findings and outcome predictors for EMPF. ANIMALS: Forty-six adult horses with EMPF. METHODS: Retrospective multicenter case series from 2009 to 2019. Radiographic (n = 27) and ultrasonographic studies (n = 19) from EMPF horses and bronchoalveolar lavage fluid (BALF) cytology from 6 EMPF and 13 asthma cases were independently reviewed and blinded to diagnosis and outcome...

The calcified chondroid mesenchymal neoplasm (CCMN) represents a recently recognized tumor type with only 50 well-documented cases in the English-language literature. Herein we report an additional case of CCMN presenting as a large mass in the temporomandibular joint region of a 41-year-old female. A review of previously reported cases and the current case of CCMN shows the following features: 1) average age 52 years (range 14-87 years) and an approximately even sex distribution; 2) most frequently involved sites: distal extremities (including foot, hand, wrist, forearm) (n=41) and temporomandibular joint/temporal/parotid region (n=9); 3) multilobular soft tissue tumor with chondroid to cartilaginous matrix, often grungy or lace-like calcifications, and variable cytologic atypia; 4) frequently detected FN1 rearrangement (n=15), including FN1 fusion with FGFR2 (n=7) or other receptor tyrosine kinases; 5) 2 reported local recurrences (after incomplete excision); 6) no reports of malignant biologic behavior...

Mucinous tubular and spindle cell carcinoma (MTSCC) shows significant overlap with papillary renal cell carcinoma (PRCC), and harbor recurrent copy-number alterations (CNA). We evaluated 16 RCC with features suggestive of MTSCC using chromosomal microarrays. The cohort was comprised of 8 females and males, each, with an age range of 33-79 years (median, 59), and a tumor size range of 3.4-15.5 cm (median, 5.0). Half the tumors were high-grade (8/16, 50%) with features such as necrosis, marked cytologic atypia, and sarcomatoid differentiation, and 5/16 (31%) were high stage (≥pT3a)...

BACKGROUND: Atypical squamous cells (ASC) in urine cytology are rarely found, and their clinical significance is not well studied. Previous studies were limited by a small number of cases and a lack of objective grading of ASC and/or their correlation with accompanying urothelial cell abnormality (UCA). METHODS: The institutional database was searched over 10 years for urine cytology reports containing ASC or from patients who had a concurrent diagnoses of high-grade (HG) urothelial carcinoma with squamous differentiation or squamous carcinoma...

BACKGROUND: Endometriosis affects more than 10% of reproductive-aged women, causing pelvic pain and infertility. Despite the benign nature of endometriosis, ovarian endometriomas carry a higher risk of developing endometrioid carcinomas (EnOCs) and clear cell ovarian carcinomas (CCCs). Atypical endometriosis, defined as cytological atypia resembling intraepithelial cancer, is considered the precursor of endometriosis-associated ovarian cancer (EAOC). This narrative review aims to provide an overview of EAOC, proposing a practical approach to clinical and therapeutic decision making...

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor. Varying sized cysts and sheets composed of three cell types (epidermoid, intermediate, and mucous cells) with varying degrees of atypia form the characteristic histological appearance of MEC. MEC frequently contains a wide variety of modified tumor cells and can be entirely cystic or completely solid. Under these circumstances, MEC requires critical differentiation from many mimickers, ranging from simple cysts and benign tumors to high-grade carcinomas...

Deleterious germline mutations in multiple genes confer an increased breast cancer (BC) risk. Immunohistochemical (IHC) expression of protein products of mutated high-risk genes has not been investigated in BC. We hypothesized that pathogenic mutations may lead to an abnormal IHC expression pattern in the tumor cells. BCs with deleterious germline mutations in CHEK2, ATM, PALB2 &PTEN were identified. Immunohistochemistry was performed using Dako staining platform on formalin fixed paraffin embedded tumor tissue...

CASE: A 40-year-old man was evaluated for a painful mass on his right calf, and a 36-year-old woman presented with a painless mass on her right foot. Final pathology revealed marked nuclear atypia and positivity for S100/SOX10 and AE1/AE3 confirming diagnoses of myoepithelial carcinoma. Both patients underwent surgical resection and are without evidence of local recurrence or metastatic disease at 1-year follow-up. CONCLUSION: Soft-tissue tumors presenting in the extremities warrant careful evaluation and timely histopathologic diagnosis...

Primary sarcomas of the jaw are very rare tumor with unclear mechanism of tumorigenesis. Identification of genetic alterations contributes to better understanding of tumorigenesis and extension of tumor spectrum, as well as potential therapeutic targets application. Herein, we firstly report a case of primary sarcoma in the mandible with novel SLMAP-BRAF fusion. Morphologically, the tumor was composed of histiocyte-like cells, larger epithelioid cells, spindle cells and osteoclast-like giant cells with moderate atypia...

Myelofibrosis is a myeloid neoplasm characterised by the presence of JAK2, CALR, or MPL mutations (with a 90% mutation frequency) and trilineage myeloid proliferation with prominent megakaryocyte atypia. People with myelofibrosis have a lower survival rate and poorer quality of life than healthy individuals. Therapy for myelofibrosis uses Janus kinase inhibitors, which reduce splenomegaly and alleviate symptoms. Regulatory approvals for Janus kinase inhibitors have focused on this dual endpoint. In this Viewpoint, we discuss the validity of using spleen reduction as a surrogate endpoint for the disease-modifying activity of candidate drugs for myelofibrosis...