Pituitary carcinoma: A cytopathologic dilemma when metastatic to cervical lymph nodes.

Pituitary carcinomas are rare tumors defined by distant metastasis or cerebrospinal spread. The morphologic features are poorly characterized because only a handful of reports have been described by fine-needle aspiration cytology. We present a case of pituitary carcinoma diagnosed in a 64-year-old male and highlight this rare entity's key cytomorphologic features and differential diagnosis.

Racial disparity in tumor microenvironment and distant recurrence in residual breast cancer after neoadjuvant chemotherapy.

Black, compared to white, women with residual estrogen receptor-positive (ER+) breast cancer after neoadjuvant chemotherapy (NAC) have worse distant recurrence-free survival (DRFS). Such racial disparity may be due to difference in density of portals for systemic cancer cell dissemination, called TMEM doorways, and pro-metastatic tumor microenvironment (TME). Here, we evaluate residual cancer specimens after NAC from 96 Black and 87 white women. TMEM doorways are visualized by triple immunohistochemistry, and cancer stem cells by immunofluorescence for SOX9. The correlation between TMEM doorway score and pro-metastatic TME parameters with DRFS is examined using log-rank and multivariate Cox regression. Black, compared to white, patients are more likely to develop distant recurrence (49% vs 34.5%, p = 0.07), receive mastectomy (69.8% vs 54%, p = 0.04), and have higher grade tumors (p = 0.002). Tumors from Black patients have higher TMEM doorway and macrophages density overall (p = 0.002; p = 0.002, respectively) and in the ER+/HER2- (p = 0.02; p = 0.02, respectively), but not in the triple negative disease. Furthermore, high TMEM doorway score is associated with worse DRFS. TMEM doorway score is an independent prognostic factor in the entire study population (HR, 2.02; 95%CI, 1.18-3.46; p = 0.01), with a strong trend in ER+/HER2- disease (HR, 2.38; 95%CI, 0.96-5.95; p = 0.06). SOX9 expression is not associated with racial disparity in TME or outcome. In conclusion, higher TMEM doorway density in residual breast cancer after NAC is associated with higher distant recurrence risk, and Black patients are associated with higher TMEM doorway density, suggesting that TMEM doorway density may contribute to racial disparities in breast cancer.

High-risk human papillomavirus testing in cytology aspiration samples from the head and neck part 1: a review of the literature on available testing options.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is increasing in incidence and is often first diagnosed on a cytology fine needle aspiration (FNA) specimen of metastatic nodal disease of the neck. In the setting of oropharyngeal squamous cell carcinoma, HPV status defines the disease with HPV-associated tumors having better overall prognosis than those that are HPV negative. Furthermore, metastatic squamous cell carcinoma of the neck of unknown origin requires testing for HPV as a positive result suggests an oropharyngeal primary. As a result, HPV testing in aspirate samples is increasingly important for the proper diagnosis and treatment of patients with head and neck squamous cell carcinoma. Although HPV testing in cervicovaginal cytology specimens is common and well-established, testing in head and neck FNA samples remains challenging. p16 immunohistochemistry is an excellent surrogate marker for HPV in tumors of known or suspected oropharyngeal origin, but the criteria used in histologic specimens may not be appropriate in cytology samples. FNA samples are more frequently hypocellular, and cytology cell blocks have variable fixation and processing steps, limiting the utility of p16 immunohistochemistry. Other potential testing options have been reported in the literature including staining of aspirate smears and molecular testing of liquid-based samples. The American Society of Cytopathology Clinical Practice Committee recently surveyed the American Society of Cytopathology membership to determine the current state of HPV testing in aspirate samples, and this review article is designed to provide a summary of the current literature on various testing options in FNA samples.

Ameloblastoma with adenoid features: Case report with cyto-histopathologic correlation and molecular findings.

Ameloblastomas are benign but locally aggressive odontogenic tumors that commonly present as expansile lesions in the tooth-bearing areas. Fine-needle aspiration (FNA) biopsies of ameloblastomas are rare in clinical practice, and only a handful of case reports and series have described their cytologic features. We present the case of a 70-year-old woman with a large and disfiguring maxillary sinus soft tissue mass sampled via transcutaneous FNA. Aspirate smears were composed of small clusters of cohesive and monotonous basaloid cells. The accompanying cellblock showed similar clusters of basaloid cells in gland-like, or "adenoid," configurations, eliciting a differential diagnosis that included sinonasal and salivary gland neoplasms. Excisional surgery material was consistent with ameloblastoma with adenoid morphology. Next-generation sequencing (NGS) analysis demonstrated FGFR2 and SMO pathogenic variants. This case exemplifies several uncommonly described features of ameloblastomas in cytology, including cyto-histologic correlation, adenoid morphology, and NGS findings. Awareness of the cytologic features of this neoplasm are important for cytopathologists confronted with maxillary sinus lesions.

NR4A3 Immunostain Is a Highly Sensitive and Specific Marker for Acinic Cell Carcinoma in Cytologic and Surgical Specimens.

OBJECTIVES: Salivary gland acinic cell carcinoma (AciCC) has recognizable cytomorphologic features that can overlap with benign and malignant entities, creating a diagnostic challenge. AciCC harbors a t(4;9) translocation increasing nuclear receptor subfamily 4 group A member 3 (NR4A3) expression, detectable by immunohistochemistry (IHC) on surgical resection (SR). NR4A3 IHC cytology data are limited. Here, we examine NR4A3 IHC on smears, cell blocks (CBs), and SRs of AciCC and its mimickers. METHODS: Our cohort comprised AciCC (including high-grade transformation), secretory carcinoma, mucoepidermoid carcinoma (MEC), Warthin tumor, pleomorphic adenoma (PA), cellular PA, carcinoma ex-PA, oncocytic carcinoma, oncocytoma, and nodular oncocytosis. NR4A3 IHC (Santa Cruz Biotechnology and Origene antibodies) was positive if more than 5% tumor cells showed nuclear staining. RESULTS: Among CBs, 90% of AciCC cases and none of the mimickers expressed NR4A3. Among SRs, 100% of AciCC cases showed diffuse NR4A3, whereas one high-grade MEC expressed focal NR4A3. Concordance was 95% with two antibody clones. Sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 100%, 100%, and 94.7% for CBs and 100%, 98.8%, 92.3%, and 100% for SRs, respectively. NR4A3 immunostaining was demonstrable on smears from an AciCC case. CONCLUSIONS: NR4A3 IHC can be a robust diagnostic tool to identify AciCC, especially for cytology specimens.

Assessment of MRI to estimate metastatic dissemination risk and prometastatic effects of chemotherapy.

Metastatic dissemination in breast cancer is regulated by specialized intravasation sites called "tumor microenvironment of metastasis" (TMEM) doorways, composed of a tumor cell expressing the actin-regulatory protein Mena, a perivascular macrophage, and an endothelial cell, all in stable physical contact. High TMEM doorway number is associated with an increased risk of distant metastasis in human breast cancer and mouse models of breast carcinoma. Here, we developed a novel magnetic resonance imaging (MRI) methodology, called TMEM Activity-MRI, to detect TMEM-associated vascular openings that serve as the portal of entry for cancer cell intravasation and metastatic dissemination. We demonstrate that TMEM Activity-MRI correlates with primary tumor TMEM doorway counts in both breast cancer patients and mouse models, including MMTV-PyMT and patient-derived xenograft models. In addition, TMEM Activity-MRI is reduced in mouse models upon treatment with rebastinib, a specific and potent TMEM doorway inhibitor. TMEM Activity-MRI is an assay that specifically measures TMEM-associated vascular opening (TAVO) events in the tumor microenvironment, and as such, can be utilized in mechanistic studies investigating molecular pathways of cancer cell dissemination and metastasis. Finally, we demonstrate that TMEM Activity-MRI increases upon treatment with paclitaxel in mouse models, consistent with prior observations that chemotherapy enhances TMEM doorway assembly and activity in human breast cancer. Our findings suggest that TMEM Activity-MRI is a promising precision medicine tool for localized breast cancer that could be used as a non-invasive test to determine metastatic risk and serve as an intermediate pharmacodynamic biomarker to monitor therapeutic response to agents that block TMEM doorway-mediated dissemination.

A rare case of primary effusion lymphoma in HIV negative patient: Diagnostic challenges and literature review.

We present a rare case of primary effusion lymphoma (PEL) in a 75 year old, HIV-negative male patient with multiple comorbidities. Imaging studies revealed a massive right pleural effusion and a significant lung collapse with multiple plural soft tissue nodules. Immediate thoracentesis was performed. Cytologic evaluation of the pleural fluid showed abnormally large cell with increased nuclear to cytoplasmic ratio, irregular nuclear contours and prominent nucleoli, with phenotypic expression of HHV-8, CD138, CD30, and MUM1 markers and negative staining for epithelial and mesothelial markers. PEL is a rare and aggressive large B-cell lymphoma often affecting immunocompromised adults and is mostly associated with human herpes virus 8/Kaposi sarcoma-associated herpes virus (HHV-8/KSHV). However, cases in immunocompetent elderly patients have been reported. The cytomorphologic features of PEL overlaps with those of aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, and anaplastic large-cell lymphoma. Also, mesothelioma, metastatic carcinoma or melanoma should be considered in the differential diagnosis. Hence, PEL should be kept in mind in the diagnostic algorithm of cytological evaluation of serosal fluid not only in HIV positive patients but also HIV-negative elderly patients. In this report, we aim to highlight the cytologic and immunohistochemical staining pattern of this rare entity to increase awareness of this entity among cytopathologists.

Adenomatous neuroendocrine tumors of the middle ear (MEANTs) with local invasion and lymph nodes metastasis: A brief report of a rare neoplasm.

Adenomatous neuroendocrine tumors of the middle ear (MEANTs) are very rare neoplasms which are composed of both epithelial and neuroendocrine components. They have mostly bland histology and indolent biological behavior, yet they may recur and metastasize. Here we present a case of MEANT with ipsilateral local brain, bone and nerve invasion and bilateral cervical lymphadenopathy in a 48 years old male with history of recurrent chronic otitis media and cholesteatoma. The patient underwent an initial fine-needle aspiration biopsy (FNAB) of an enlarged cervical lymph node followed by surgical excision of the tumor and immunohistochemistry which confirmed the diagnosis.

Educational Case: Diagnostic Approach to Salivary Gland Neoplasms.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040. 1.

Follicular dendritic cell sarcoma: Cytomorphologic features and diagnostic challenges.

Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm, which primarily arises in lymph nodes with occasional cases occurring in extranodal locations. The diagnosis is often challenging particularly on cytology fine needle aspiration due to overlapping morphologic and immunohistochemical features. We present a case of FDCS diagnosed in an otherwise asymptomatic 33-year old male. The aim of our case report is to highlight the key cytomorphologic features and discuss various differential diagnoses of this unusual entity.

COVID-19: a Disease with a Potpourri of Histopathologic Findings-a Literature Review and Comparison to the Closely Related SARS and MERS.

Since the coronavirus disease 2019 (COVID-19) pandemic has hit the entire world, there is ample knowledge regarding its clinical course and prognostic biomarkers. Still, the pathophysiology of COVID-19 is poorly understood. Since the first guidelines published in February 2020 for autopsy of both confirmed and suspected COVID-19 cases, there has been an increasing number of autopsies and literature reporting histopathological findings. However, our knowledge about the immunological response of various organ systems to the virus, as well as response patterns, is inadequate but is essential to understand and initiate timely and targeted antiviral, anti-inflammatory, or anticoagulative therapy. Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is primarily considered a respiratory virus, current evidence shows that it causes life-threatening complications in almost all organ systems including the heart, brain, kidney, spleen, liver, and eyes. Hence, in this article, we reviewed the published case reports and case series in order to increase our understanding of COVID-19 pathophysiology. The main histopathological findings of the lungs include diffuse alveolar damage with activated type II pneumocytes, fibroblasts, protein-rich exudate, and hyaline membranes. Other significant histopathological findings include cardiomegaly, right ventricular dilation, splenic pulp atrophy, kidneys with severe podocytopathy, and collapsing glomerulopathy, and the brain showed hypoxic changes in the cerebellum and cerebrum. Furthermore, in this review, we also explained different pathological findings of SARS-CoV and MERS and compared them to SARS-CoV-2. This comprehensive review will improve our understanding of COVID-19 pathophysiology and various disease stages, hence promoting the application of targeted therapy.

The Cancer Cell Dissemination Machinery as an Immunosuppressive Niche: A New Obstacle Towards the Era of Cancer Immunotherapy.

Although cancer immunotherapy has resulted in unpreceded survival benefits to subsets of oncology patients, accumulating evidence from preclinical animal models suggests that the immunosuppressive tumor microenvironment remains a detrimental factor limiting benefit for many patient subgroups. Recent efforts on lymphocyte-mediated immunotherapies are primarily focused on eliminating cancer foci at primary and metastatic sites, but few studies have investigated the impact of these therapies on the highly complex process of cancer cell dissemination. The metastatic cascade involves the directional streaming of invasive/migratory tumor cells toward specialized blood vessel intravasation gateways, called TMEM doorways, to the peripheral circulation. Importantly, this process occurs under the auspices of a specialized tumor microenvironment, herewith referred to as "Dissemination Trajectory", which is supported by an ample array of tumor-associated macrophages (TAMs), skewed towards an M2-like polarization spectrum, and which is also vital for providing microenvironmental cues for cancer cell invasion, migration and stemness. Based on pre-existing evidence from preclinical animal models, this article outlines the hypothesis that dissemination trajectories do not only support the metastatic cascade, but also embody immunosuppressive niches, capable of providing transient and localized immunosubversion cues to the migratory/invasive cancer cell subpopulation while in the act of departing from a primary tumor. So long as these dissemination trajectories function as "immune deserts", the migratory tumor cell subpopulation remains efficient in evading immunological destruction and seeding metastatic sites, despite administration of cancer immunotherapy and/or other cytotoxic treatments. A deeper understanding of the molecular and cellular composition, as well as the signaling circuitries governing the function of these dissemination trajectories will further our overall understanding on TAM-mediated immunosuppression and will be paramount for the development of new therapeutic strategies for the advancement of optimal cancer chemotherapies, immunotherapies, and targeted therapies.

When accurate cytomorphology directs clinical decision: Colonic adenocarcinoma presents initially with an isolated vertebral bone metastasis.

Liver is the most common site for metastasis of colonic adenocarcinoma. Other relatively common metastatic locations include: peritoneum, lungs and ovaries. Rare metastatic sites include: central nervous system, testis, uterus, oral cavity and bones. Though it is rare to have an isolated bone metastasis without liver or visceral involvement in colonic adenocarcinoma, it can occur. Our case illustrates the vital role of an accurate cytopathologic diagnosis in directing the proper clinical decision and management in our young patient. Our patient's first presentation was acute on chronic back pain radiating to his lower extremities with clinical suspicion of tuberculosis spondylitis. The correct cytopathologic diagnosis of the fine needle aspiration from the destructive vertebral lesion led to the establishment of an isolated metastatic colonic adenocarcinoma diagnosis initially and directed the clinical management of our patient.

Educational Case: Testicular Germ Cell Tumor: Clinical Presentation, Pathogenesis, and Diagnostic and Therapeutic Modalities.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Educational Case: Pancreatic Adenocarcinoma: Clinical Presentation, Pathogenesis, Diagnostic, and Therapeutic Modalities.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Safety during crisis: Rapid on-site evaluation at the time of COVID-19 pandemic.

The COVID-19 pandemic is posing a worldwide challenge to control and contain. SARS-CoV-2 is a highly infectious virus. Health care providers at the front lines are at high risk of getting the infection and the risk applies also to laboratory personnel as they deal with specimens that might be contaminated with infectious materiel. Cytopathology teams specifically are at high risk of dealing with contaminated material because of patients encounter during fine-needle aspiration biopsies or Rapid On-Site Evaluation (ROSE) for adequacy. In our article, we discuss alternative safer staining methods to the widely used Diff-Quick stain that can be utilized for ROSE to decrease the risk of viral exposure during the current COVID-19 pandemic.

Laboratory Safety: Chemical and Physical Hazards.

Chemical and physical hazards are part of the daily routine when working in biorepositories. This chapter provides a brief overview of some common physical and chemical hazards encountered in biorepositories, with some basic principles to help eliminate and control these hazards by implementing safe work practices.

A 58-Year-Old Woman With Back Pain and an Unusual Diagnosis.

CASE PRESENTATION: A 58-year-old postmenopausal woman presented to her primary care physician with lower back pain. She denied respiratory symptoms. Her medical history is significant for hypertension, hyperlipidemia, and prediabetes. Her surgical history consists of a tonsillectomy and a remote dilatation and curettage procedure. She denied a history of smoking, alcohol use, or recreational drug use. A review of systems was otherwise negative.

Splenic Angiosarcoma Diagnosed on Bone Marrow Biopsy: Case Report and Literature Review.

Primary splenic angiosarcoma carries a poor prognosis and is among the rarest forms of malignancy. An overwhelming majority of patients with splenic angiosarcoma will develop metastases. However, osseous metastatic disease is rare. We present an 83 year old hispanic female who was diagnosed with primary splenic angiosarcoma on bone marrow biopsy performed for a hematologic workup. We highlight key historical, laboratory, imaging, and pathological features of splenic angiosarcoma. The synthesis of both imaging features and clinical history is essential for establishing early diagnosis in these patients.

A case of primary squamous cell carcinoma of the gallbladder with local invasion of the liver and peritoneum, and metastasis to the omentum.

Primary squamous cell carcinoma of the gallbladder is a rare entity that comprises approximately 1%-3% of all primary gallbladder cancers. We report the case of a 37-year-old woman who was diagnosed with a locally invasive squamous cell carcinoma of the gallbladder. Surgical pathology revealed a predominantly squamous cell carcinoma composition of the tumor with a few microscopic foci of adenocarcinoma (<1% of tumor). We discuss pertinent clinical features, risk factors, and imaging characteristics to prompt early diagnosis and treatment, which will ultimately lead to improved patient outcomes.