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Dive into the research topics where David C. Howlett is active.

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Featured researches published by David C. Howlett.


British Journal of Oral & Maxillofacial Surgery | 2011

Imaging the major salivary glands

C.J. Burke; R.H. Thomas; David C. Howlett

Advances in imaging have led to improved sensitivity in the diagnosis of diseases that involve the major salivary glands. Ultrasound (US), plain radiography and sialography, magnetic resonance imaging (MRI), computed tomography (CT), and nuclear scintigraphy/positron emission tomography (PET) all play a part, and imaging often assists in the planning of further management, operative or otherwise. We review the methods used for imaging the major salivary glands, and apply the indications for these methods to the principal pathological processes.


Clinical Radiology | 2010

A study to evaluate the accuracy of ultrasound in the diagnosis of parotid lumps and to review the sonographic features of parotid lesions - results in 220 patients.

N. Sriskandan; A. Hannah; David C. Howlett

AIMnTo assess the accuracy of ultrasound in characterizing benign and malignant parotid lesions and to review their sonographic features.nnnMATERIALS AND METHODSnA retrospective analysis of 220 ultrasound examinations was undertaken in 220 patients who presented with palpable parotid lesions over an 11-year period and correlated with the clinico-histopathological findings. The original sonographic diagnosis was compared to the final histopathology and lesions characterized using previously established sonographic criteria.nnnRESULTSnHistopathology results were available for all patients. Two hundred and one patients had focal lesions: 29 carcinomas, 21 lymphomata and 151 benign lesions (including 69 pleomorphic adenomas and 54 Warthins tumours); 19 patients did not have focal lesions. The initial ultrasound report was indeterminate in 25/201 focal lesions. In the remaining 176 lesions, the sensitivity, specificity, and diagnostic accuracy for malignancy of ultrasound was 91, 93, and 93%, respectively. There were four false-negatives and nine false-positives with a crossover of apparently benign and malignant features. Pleomorphic adenomas and Warthins tumours were poorly differentiated using ultrasound. Additional impalpable parotid lesions or adenopathy were detected in 44 patients using ultrasound.nnnCONCLUSIONnUltrasound is a valuable adjunct to clinical examination, accurately differentiating benign from malignant lesions and diagnosing non-focal disease. There is an overlap in features of pleomorphic adenomas and Warthins tumours and of some benign and malignant lesions. Diagnostic ultrasound should be combined with needle biopsy in most patients to maximize diagnostic yield.


Ejso | 2015

Image-guided core needle biopsy in the diagnosis of malignant lymphoma

E. Skelton; A. Jewison; C. Okpaluba; J. Sallomi; J. Lowe; Keith Ramesar; R. Grace; David C. Howlett

OBJECTIVEnCurrent European Society for Medical Oncology (ESMO) guidelines recommend that when feasible, surgical excision biopsy (SEB) is the ideal for diagnosis, sub-typing and grading of malignant lymphoma. We undertook this retrospective study to assess the diagnostic accuracy of image-guided core needle biopsy (CNB) in the diagnosis of malignant lymphoma, to identify the proportion of cases from which oncological treatment was subsequently instigated from the CNB diagnosis, and to evaluate the potential role for minimally invasive CNB techniques in the diagnostic pathway of malignant lymphoma.nnnMETHODSnAll cases of lymphoma amenable to CNB between 2008 and 2013 were included. Patient records were reviewed to identify the biopsy diagnostic pathway undertaken (fine needle aspiration cytology, CNB, surgical excision biopsy). CNB specimens were graded as fully diagnostic (tumour sub-typing/grading and treatment initiated), partially diagnostic (diagnosis of lymphoma but more tissue required for sub-typing/grading), equivocal or inadequate. The effects of anatomical location, needle gauge, number of core specimens and sub-type of disease on the diagnostic yield of the sample were analysed.nnnRESULTSn262 patients and 323 biopsy specimens were included in the study. 237 patients underwent CNB as the initial diagnostic intervention. In 230/237 CNB was fully diagnostic (97%), allowing initiation of treatment. In 7 patients, SEB was necessary in addition to CNB to provide additional diagnostic information to allow initiation of treatment. In 72 patients, SEB was the only diagnostic test performed.nnnCONCLUSIONnOur study showed that in 97% of suitable cases, CNB provided sufficient diagnostic information to allow treatment of malignant lymphoma to be instigated. This minimally-invasive technique is well tolerated and has advantages over surgical techniques, including reduced costs, post-procedural complications and delays on the diagnostic pathway. CNB may obviate the use of surgical techniques in the majority of suitable cases, however its success is dependent on close collaboration and acceptance by clinicians and pathologists.


World Journal of Radiology | 2016

Biopsy of parotid masses: Review of current techniques

Sananda Haldar; Joseph Dalby Sinnott; Kemal Tekeli; Samuel S Turner; David C. Howlett

Definitive diagnosis of parotid gland masses is required optimal management planning and for prognosis. There is controversy over whether fine needle aspiration cytology (FNAC) or ultrasound guided core biopsy (USCB) should be the standard for obtaining a biopsy. The aim of this review is to assess the current evidence available to assess the benefits of each technique and also to assess the use of intra-operative frozen section (IOFS). Literature searches were performed using pubmed and google scholar. The literature has been reviewed and the evidence is presented. FNAC is an accepted and widely used technique. It has been shown to have variable diagnostic capabilities depending on centres and experience of staff. USCB has a highly consistent diagnostic accuracy and can help with tumour grading and staging. However, the technique is more invasive and there is a question regarding potential for seeding. Furthermore, USCB is less likely to be offered as part of a one-stop clinic. IOFS has no role as a first line diagnostic technique but may be reserved as an adjunct or for lesions not amenable to percutaneous biopsy. On balance, USCB seems to be the method of choice. The current evidence suggests it has superior diagnostic potential and is safe. With time, USCB is likely to supplant FNAC as the biopsy technique of choice, replicating that which has occurred already in other areas of medicine such a breast practice.


British Journal of Oral & Maxillofacial Surgery | 2015

Establishing an accurate diagnosis of a parotid lump: evaluation of the current biopsy methods – fine needle aspiration cytology, ultrasound-guided core biopsy, and intraoperative frozen section

David C. Howlett; E. Skelton; A.B. Moody

The optimum technique for histological confirmation of the nature of a parotid mass remains controversial. Fine needle aspiration cytology (FNAC), which has traditionally been used, is associated with high non-diagnostic and false negative rates, and ultrasound (US)-guided core biopsy and frozen section have been explored as alternatives. US-guided core biopsy is more invasive than FNAC, but is safe, well-tolerated, and associated with improved diagnostic performance. Although frozen section offers better specificity than FNAC, it has a number of important drawbacks and cannot be considered as a primary diagnostic tool. US-guided core biopsy should be considered as the initial diagnostic technique of choice, and in units where the accuracy of FNAC is good it can be used when FNAC is equivocal or non-diagnostic.


Radiology Case Reports | 2011

Male breast carcinoma and the use of MRI.

Aidan Shaw; Benjamin Smith; David C. Howlett

MRI is well established in the diagnosis of female breast cancer, with an important role as a problem-solving tool in the postoperative breast and in implant evaluation. Little in the literature mentions the use of MRI in male breast cancer, with there is no clear role for its use at present. We present an unusual case of bilateral male breast carcinoma and demonstrate a similar enhancement pattern to that described in female breast cancer; we also suggest other potential applications of MRI for the male breast.


International Journal of Oral and Maxillofacial Surgery | 2014

Evaluation of biopsy methods in the diagnosis of submandibular space pathology.

B.O. Olubaniyi; V. Chow; U. Mandalia; S. Haldar; Gulcan Gok; P. Michl; K. Ramesar; E. Sellon; Michael Williams; David C. Howlett

The aim of this study was to evaluate the performance of fine needle aspiration cytology (FNAC), ultrasound-guided core needle biopsy (USCNB), punch biopsy, and surgical excision biopsy in neoplasms presenting within the submandibular space. A retrospective analysis of all patients with a pathological diagnosis of a submandibular space neoplasm within a 12-year period (February 1999 to June 2011) was performed. Biopsy results were compared to histopathological diagnosis obtained from surgical excision biopsy. Eighty-one specimens from 44 patients met the search criteria (15 FNAC, 24 USCNB, 7 punch biopsy, and 35 surgical excision biopsy). The final diagnosis was established by USCNB, punch biopsy, or surgical excision biopsy and not by FNAC alone. Surgical excision biopsy was performed as a primary diagnostic (n = 8), secondary diagnostic (n = 15), or as a post-diagnostic therapeutic procedure (n = 12). Non-diagnostic results were: FNAC 11/15, USCNB 2/24, and punch biopsy 1/7. Diagnostic results were: FNAC 2/15, USCNB 20/24, and punch biopsy 5/7. No complications were reported. Although punch biopsy demonstrated good yield and accuracy, its use is restricted to a small cohort of patients. USCNB is a safe and accurate technique in the submandibular space, with a low non-diagnostic rate.


British Journal of Hospital Medicine | 2016

Liver biopsy: past, present and future.

Srivathsan Ravindran; Sarah Helen Hancox; David C. Howlett

Liver biopsy is an integral part of evaluation of liver disease. Indications and techniques have developed to allow functional and prognostic liver assessment, along with biochemistry and dynamic imaging, in both diffuse and focal liver disease. However, non-invasive techniques are changing the way clinicians use liver biopsy.


BMJ | 2012

Ultrasound guided core biopsy is the diagnostic tool of choice in salivary gland swellings.

Edward Sellon; A.B. Moody; David C. Howlett

Mehanna and colleagues’ section on obtaining a tissue diagnosis in salivary gland swellings merits further comment.1nnFine needle aspiration cytology (FNAC) has traditionally been the biopsy technique of choice in the parotid glands. It is quick, safe, and can be highly accurate, although it requires optimised conditions to perform well. In clinical practice such conditions are rarely …


Clinical Radiology | 2016

Perceptual type error in everyday practice

Emma Owens; N.R. Taylor; David C. Howlett

Discrepancy or quality improvement meetings are good practice and are now commonplace in most Radiology Departments, with the aim of improving diagnostic accuracy, preventing recurrent and common mistakes, improving the radiological report and thereby improving patient care. A total of 122 cases were assessed from a two-year period. This review highlights some of the more common, recurrent and important issues encountered within a general hospital with an emphasis on learning points and review areas.

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Benjamin Smith

East Sussex County Council

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Emily Skelton

East Sussex County Council

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Gulcan Gok

East Sussex County Council

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A.B. Moody

East Sussex County Council

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N. Woodhouse

East Sussex County Council

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Michael Williams

East Sussex County Council

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A Shaw

East Sussex County Council

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