Derek B. Allison
Johns Hopkins University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Derek B. Allison.
Diagnostic Cytopathology | 2017
Derek B. Allison; Austin McCuiston; Satomi Kawamoto; David W. Eisele; Justin A. Bishop; Zahra Maleki
The use of fine‐needle aspiration (FNA) cytology for the preoperative evaluation of salivary gland lesions is an accepted but, currently, nonstandardized practice. More specifically, cystic major salivary gland lesions are relatively rare and can be very challenging to diagnose on FNA due to low cellularity and an incredibly broad differential diagnosis. The purpose of this study was to investigate the diagnostic utility of preoperative FNA cytology for cystic major salivary gland lesions.
Cancer Cytopathology | 2017
Derek B. Allison; Paul E. Wakely; Momin T. Siddiqui; Syed Z. Ali
Nodular fasciitis (NF) is a benign, self‐limited, fibroblastic/myofibroblastic proliferation that is diagnostically challenging, often mimicking a malignant process due to its rapid growth clinically and its high cellularity, mitotic activity, and variable/nonspecific cytomorphologic findings. Herein, the authors report what to their knowledge is the largest and first multi‐institutional study of the cytomorphologic characteristics of NF by fine‐needle aspiration (FNA).
Cancer Cytopathology | 2017
Mohammed Lilo; Derek B. Allison; Bouchra K. Younes; Min Cui; Fred Askin; Edward Gabrielson; Qing Kay Li
The sensitivity and specificity of positron emission tomography (PET) have been significantly improved for the identification of malignancies in recent years; however, it is still necessary to confirm PET findings in a lymph node (LN) by direct tissue sampling. Endobronchial ultrasound–guided transbronchial needle aspiration (EBUS‐TBNA) is the most commonly used approach for diagnosing and staging mediastinal LNs, particularly in lung cancer patients with locally advanced disease. Despite this fact, evidence‐based studies of EBUS‐TBNA cytology and PET findings are still suboptimal.
Acta Cytologica | 2017
Mohammed Lilo; Christopher VandenBussche; Derek B. Allison; Anne Marie Lennon; Bouchra K. Younes; Ralph H. Hruban; Christopher L. Wolfgang; Syed Z. Ali
Objectives: Pancreatic serous cystadenomas (SCAs) are benign tumors. Technological advances in imaging have led to increased recognition of asymptomatic pancreatic cysts, consequently increasing the demand for cytomorphologic evaluations of cyst fluid. Study Design: A retrospective search through the pathology archives over an 11-year period was performed to identify SCAs from pancreatectomy specimens with a presurgical pancreatic EUS-guided fine-needle aspiration (FNA). Results: Fifty-one FNAs were identified. The average patient age was 59.9 years and 34 (67%) were female. Thirty-five (69%) of the SCAs were located in the body or tail of the pancreas. SCAs ranged in size from 1.3 to 8.0 cm (mean 4.9). On imaging, features suggestive of SCA were seen in 7 (14%) cases. The cytologic diagnoses were as follows: SCA in 5 (10%) cases, suspicious for mucin-producing neoplastic cyst in 4 (8%), pseudocyst in 4 (8%), and benign ductal and/or acinar epithelium, not otherwise specified in 24 (47%). Additionally, 14 (27%) cases were deemed nondiagnostic. Conclusions: A cytopathologic diagnosis of SCA on FNA is extremely difficult. The salient cytomorphologic features for identifying SCAs included scant cellularity, a mostly clear background, absence of extracellular mucin, hemosiderin-laden macrophages, and loose fragments of cuboidal cells with a notable absence of necrosis, atypia, and mitoses.
Cancer Cytopathology | 2016
Derek B. Allison; Mohammed Lilo; Susan Geddes; Aparna Pallavajjalla; Frederic B. Askin; Edward Gabrielson; Gang Zheng; Qing Kay Li
Phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha (PIK3CA) mutations and amplification are detected in 1% of primary lung adenocarcinomas (ADCs) and in 38% of primary lung squamous cell carcinomas. Alterations of PIK3CA in metastatic non–small cell lung carcinoma (NSCLC), however, are still not fully understood. This study investigated PIK3CA alterations in metastatic ADCs and correlated the findings with those for other commonly tested molecular abnormalities via fine‐needle aspiration (FNA) and small‐core biopsy materials.
Cancer Cytopathology | 2018
Derek B. Allison; Patricia J. Simner; Syed Z. Ali
Cytology samples obtained from exfoliative sources and fine‐needle aspiration (FNA) procedures can all be used to detect microorganisms and/or the associated cytopathologic effects (CPE) caused by an infection. There are many advantages to utilizing cytology samples as an adjunct to routine microbiology laboratory methods. For example, cytology samples can be obtained by non‐invasive and minimally invasive techniques, and interpretation is affordable, accurate, and fast. Furthermore, routine cytology stains, including the Papanicolaou (Pap) and the Diff‐Quik (DQ) stains, can adequately identify a number of microorganisms. Finally, material obtained by these procedures can also be used for cytologic ancillary testing, microbiology culture, and molecular studies. Currently, there are a variety of ancillary diagnostic techniques that are routinely utilized in the cytopathology laboratory. Additionally, the increasing utilization of molecular‐based, diagnostic techniques on fluid specimens, as well as FFPE material, is expanding the role of cytopathology for infectious disease diagnostics. In this review, we provide an overview of the most practical ancillary techniques commonly used to identify microorganisms on cytology specimens.
Acta Cytologica | 2018
Derek B. Allison; Rajni Sharma; Morgan L. Cowan; Christopher VandenBussche
Objectives: Telomerase activity can be detected in up to 90% of urothelial carcinomas (UC). Telomerase activity can also be detected in urinary tract cytology (UTC) specimens and indicate an increased risk of UC. We evaluated the performance of a commercially available antibody that putatively binds the telomerase reverse transcriptase (hTERT) subunit on 500 UTC specimens. Study Design: Unstained CytospinTM preparations were created from residual urine specimens and were stained using the anti-hTERT antibody (SCD-A7). Two algorithms were developed for concatenating the hTERT result and cytologic diagnosis: a “no indeterminates algorithm,” in which a negative cytology and positive hTERT result are considered positive, and a “high-specificity algorithm,” in which a negative cytology and positive hTERT result are considered indeterminate (and thus negative for comparison to the gold standard). Results: The “no indeterminates algorithm” and “high-specificity algorithm” yielded a sensitivity of 60.6 and 52.1%, a specificity of 70.4 and 90.7%, a positive predictive value of 39.1 and 63.8%, and a negative predictive value of 85.0 and 85.8%, respectively. Conclusions: A positive hTERT result may identify a subset of patients with an increased risk of high-grade UC (HGUC) who may otherwise not be closely followed, while a negative hTERT immunocytochemistry result is associated with a reduction in risk for HGUC.
Journal of the American Society of Cytopathology | 2016
Mohammed Lilo; Derek B. Allison; Yuting Wang; Ming Hui Ao; Edward Gabrielson; Susan Geddes; Hui Zhang; Frederic B. Askin; Qing Kay Li
Journal of the American Society of Cytopathology | 2016
Derek B. Allison; James Adam Miller; Stephanie Coquia; Zahra Maleki
Journal of the American Society of Cytopathology | 2016
Derek B. Allison; Zahra Maleki