Johan Grobbelaar

Dr. Johan Grobbelaar

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 November 2023 in Cells
Verified
Journal Article
Open access
PDF file
DTDada Temilola
Dada Temilola
HAHenry Ademola Adeola
Henry Ademola Adeola
JGJohan Grobbelaar
Johan Grobbelaar
MCManogari Chetty
Manogari Chetty
The rising mortality and morbidity rate of head and neck cancer (HNC) in Africa has been attributed to factors such as the poor state of health infrastructures, genetics, and late presentation resulting in the delayed diagnosis of these tumors. If well harnessed, emerging molecular and omics diagnostic technologies such as liquid biopsy can potentially play a major role in optimizing the management of HNC in Africa. However, to successfully apply liquid biopsy technology in the management of HNC in Africa, factors such as genetic, socioeconomic, environmental, and cultural acceptability of the technology must be given due consideration. This review outlines the role of circulating molecules such as tumor cells, tumor DNA, tumor RNA, proteins, and exosomes, in liquid biopsy technology for the management of HNC with a focus on studies conducted in Africa. The present state and the potential opportunities for the future use of liquid biopsy technology in the effective management of HNC in resource-limited settings such as Africa is further discussed.

6 January 2025 in Journal of the Colleges of Medicine of South Africa
Verified
Journal Article
Open access
PDF file
JGJohan Grobbelaar
Johan Grobbelaar
KWKathryne E. Wright
Kathryne E. Wright
ATAnn Thomas
Ann Thomas
SAShaun Edward Adam
Shaun Edward Adam
Background: This study reports on our local incidence of minor salivary gland tumours (MSGT).Methods: This was a retrospective descriptive study including all patients with MSGT treated at Tygerberg Hospital from 2015 to 2024.Results: Benign and malignant tumours’ incidence was almost equal at 46.46% and 53.54%, respectively (N = 99). Pleomorphic adenomas were the most common tumour overall (38.38%) and the most common benign tumour. Polymorphous low-grade adenocarcinoma (PLGA) was the most common malignant tumour (15.15%). The palate was the most common site. Primary sites other than lips and palate had a 93.23% malignant incidence. Benign tumours occurred statistically significantly in younger patients than malignant tumours (p 0.001) (42.74 years versus 56.02 years).Conclusion: We did not see the high malignant incidence that is frequently reported in otorhinolaryngology textbooks. Pleomorphic adenomas remain the most common and occur most commonly in the palate. We did show an unusually high incidence of PLGA. Primary sites other than palate and lips should raise the suspicion of malignant MSGT.Contribution: The study highlights the importance of reporting on local data because disease patterns may vary greatly based on genetic and geographical differences. Further investigation is needed to explain possible local factors contributing to the high incidence of PLGA.

21 May 2025 in Sinusitis
Verified
Journal Article
Open access
PDF file
TSTessa Kirsty Suttle
Tessa Kirsty Suttle
JGJohan Grobbelaar
Johan Grobbelaar
ULUrsula Lesar
Ursula Lesar
RDRazaan Davis
Razaan Davis
LRLeon Janse van Rensburg
Leon Janse van Rensburg
SAShaun Edward Adam
Shaun Edward Adam
This case report presents the clinical evaluation of an 11-year-old boy with a unilateral polypoid nasal mass causing nasal obstruction, facial asymmetry, and intermittent epistaxis. His clinical picture raised concerns of a juvenile nasopharyngeal angiofibroma; however, further imaging and histopathological evaluation ultimately confirmed the diagnosis of allergic fungal rhinosinusitis (AFRS). Although this patient was younger in age than those traditionally associated with AFRS, classical features present on both computed tomography (CT) and magnetic resonance imaging (MRI) aided in his diagnosis and management. This case underscores the importance of a comprehensive diagnostic approach when evaluating unilateral sinonasal masses in paediatric patients, specifically in atypical presentations where the diagnosis of AFRS may not initially be considered. It highlights the critical role of imaging as a diagnostic tool, specifically CT and MRI, which were pivotal in the work-up and management of this case. Additionally, the need for caution during biopsies of sinonasal masses in children is emphasised, as there is potential for catastrophic bleeding in vascularised masses such as juvenile nasopharyngeal angiofibroma. This case demonstrates that AFRS can occur in younger children, highlighting the need to include this in the differential diagnosis, even in patients outside of the traditionally described age group.

23 December 2023 in South African Journal of Radiology
Verified
Journal Article
Open access
PDF file
MWMonica Van Wijk
Monica Van Wijk
LRLeon Janse van Rensburg
Leon Janse van Rensburg
BBBianca D. Berndorfler
Bianca D. Berndorfler
JOJohan F. Opperman
Johan F. Opperman
JGJohan Grobbelaar
Johan Grobbelaar
RDRazaan Davis
Razaan Davis
Phosphaturic mesenchymal tumours (PMT) are rare, benign lesions and the most common tumour to cause tumour-induced osteomalacia (TIO), a paraneoplastic syndrome. Patients frequently exhibit severe osteomalacia, accompanied by multiple fractures, which significantly impair their quality of life. Complete surgical resection is curative.Contribution: A rare case of sinonasal PMT is presented, with a focus on the imaging findings and role of the radiologist and nuclear physician.

1 March 2026 in South African Journal of Surgery
Verified
Journal Article
Closed access
JGJohan Grobbelaar
Johan Grobbelaar
JOJ Opperman
J Opperman
AAA Afrogheh
A Afrogheh
PSPt Schubert
Pt Schubert
SASe Adam
Se Adam

1 March 2026 in South African Journal of Surgery
Verified
Journal Article
Closed access
JGJohan Grobbelaar
Johan Grobbelaar
SOSm Oelofsen
Sm Oelofsen
JOJf Opperman
Jf Opperman
AAA Afrogheh
A Afrogheh
SASe Adam
Se Adam