UNASSIGNED: This study aimed to report an uncommon site of origin of a rare head-and-neck cancer, namely malignant granular cell tumour.
UNASSIGNED: An 89-year-old female patient complained of persistent pharyngodynia and odynophagia for two months.
UNASSIGNED: Upon clinical examination, the right palatine tonsil was larger and palpably firmer than the contralateral. An incisional biopsy of the lesion was performed under local anaesthesia revealing malignant granular cell tumour. A contrast-enhanced computed tomography (CECT) scan of the head and neck and an 18F-fluoro-2-deoxy-D-glucose positron emission tomography (PET) scan confirmed the presence of a pathologic appearance of the right palatine tonsil without nodal or distant metastasis.
UNASSIGNED: Following a multidisciplinary consultation and the patient\'s informed permission, a right tonsillectomy extended to the constrictor muscle fibres of the upper pharynx was performed.
UNASSIGNED: The tumour was staged as pT2 R0 cN0 M0, according to the AJCC 8th edition for soft-tissue tumours of the head and neck. Due to the early stage and the radicality of surgery, no further adjuvant treatments were provided. The patient is currently followed up with no evidence of disease one year post-operatively.
UNASSIGNED: Granular cell tumours are rare mesenchymal tumours, firstly described by the pathologist Abrikossoff in 1926. This type of tumour constitutes approximately 0.5% of all soft-tissue tumours, and can affect any part of the body, with the head and neck being the most frequently involved site. The tonsil is an extremely rare localisation of this cancer. The differential diagnosis of unilateral tonsillar enlargement should also include this histological entity.

Granular cell tumour is a rare, mostly benign, soft tissue, neuroectodermal tumour, most commonly seen in the skin and peripheral soft tissue. There are no publications to date of PSMA-PET avidity in a granular cell tumour. In this 60 year old male, staging PSMA-PET for a localized intermediate risk prostate cancer incidentally identified a PSMA-avid left supraspinatus lesion, which was subsequently biopsy-proven as a granular cell tumour. We present the first case of PSMA-avid granular cell tumour and add to the growing literature documenting PSMA-PET avidity in benign and malignant lesions apart from prostate cancer.

Morphological overlap exists between cutaneous granular cell tumours (GCT) and malignant melanoma, with the melanocyte-specific markers HMB45 and Melan-A commonly used to support the diagnosis of melanoma. We recently encountered several cases of GCT in our practice showing strong expression of Melan-A. The aim of this study was to establish the prevalence of positive immunohistochemical staining for Melan-A and HMB45 in a series of unequivocal GCTs. We also aimed to assess the prevalence of staining for PRAME (PReferentially expressed Antigen in MElanoma), a marker expressed in >80% of primary melanomas as well as many non-melanocytic tumours. A total of 20 cutaneous/subcutaneous GCTs were evaluated using Melan-A, HMB45 and PRAME immunohistochemistry. Staining for Melan-A and HMB45 was scored using a semiquantitative scale from 0 (absent) to 3+ (staining present in >50% of tumour cells). PRAME expression was recorded as either positive (>75% of cell nuclei staining) or negative. Melan-A expression was observed in four GCTs (20%), with strong and diffuse (3+) staining seen in two cases (10%), both from anogenital areas. Weak patchy nuclear PRAME expression was seen in every case, interpreted to be negative. HMB45 was also negative in all cases (100%). Our study demonstrates that Melan-A expression can be strong and diffuse in a subset of otherwise unequivocal cutaneous GCTs, which may cause diagnostic confusion with malignant melanoma. HMB45 and PRAME did not stain any of the GCTs in our series.

Granular cell tumour (GCT) is a relatively rare, benign tumour. The cells of a GCT are composed of large polygonal cells containing numerous eosinophilic granules in the cytoplasm and are thought to be of neural origin. GCT can occur anywhere on the body, but most commonly it is located on the tongue. GCT possess the potential for malignant transformation, and as such should be resected; the risk of malignant transformation is estimated to be 1%-2%. Patients generally do not require routine follow-up following excision with clear margins. Here, we present a case of a GCT of the tongue which had been present for 4 years in an otherwise healthy 35-year-old male. The lesion had been stable in size and appearance, and the patient was asymptomatic. An incision biopsy of the lesion revealed findings consistent with a GCT, and the patient underwent a wide local excision shortly after incision biopsy.

The cytomorphological features of benign mesenchymal tumours of the tongue have rarely been reported. Herein, we present the cytomorphological features of adult-type rhabdomyoma, which occurred in the tongue of a female patient, and granular cell tumour (GCT), which occurred in the tongue of a male patient; both patients were in their mid-50s. The cytological features of the adult-type rhabdomyoma case included large polygonal to ovoid cells with abundant and granular cytoplasm with predominantly peripherally located, uniform, round to oval nuclei and small nucleoli. Cross-striation and crystalline intracytoplasmic structures were not seen. The cytological features of the GCT case included large cells with abundant granular pale cytoplasm, small round nuclei and small distinct nucleoli. The cytological differential diagnoses of these tumours overlap; thus, the cytological findings of the different entities included in their differential diagnoses are discussed.

Intracranial granular cell tumours (GCT) are uncommon neoplasms of uncertain cellular origin that are rarely reported in dogs. This case series describes three aged dogs that presented with neurological signs in which magnetic resonance (MR) imaging revealed plaquelike extra-axial lesions that were hypointense on T2-weighted (T2w) images. The surgical biopsy of the lesions and necropsies were followed by histochemical characterisation with periodic acid-Schiff (PAS) staining and immunohistochemistry with ubiquitin, S-100, and SOX-10 to elucidate the cellular origin. The immunohistochemical study indicated that these intracranial GCTs were not of Schwann cell origin. In conclusion, GCTs should be considered a differential diagnosis of intracranial, extra-axial hypointense brain lesions on T2w MR images.

OBJECTIVE: Granular cell tumours (GCTs) of the pancreas are mostly benign and exceptionally rare, with no unique identifying radiological features. Following a case discussion of a patient with GCT, a comprehensive review of available literature was conducted to identify the common diagnostic features associated with GCT.
METHODS: Following a case report identified in our institution, a systematic review was conducted by two authors in accordance with Preferred Reporting Items for Systematic review and Meta-Analysis protocols (PRISMA) guidelines. Databases MEDLINE, EMBASE, Scopus, World of Science, and grey literature were searched on August 2021. Inclusion criteria were histopathology diagnosed granular cell tumour of the pancreas.
RESULTS: A 37-year-old male presented with 1 month of abdominal pain and an MRI demonstrating a dilated main pancreatic duct, distal parenchymal atrophy, but no focal lesion. Repeat MRI at 6 months re-demonstrated similar findings and subsequent endoscopic ultrasound was suspicious for main duct IPMN. Following multidisciplinary team discussion, a spleen-preserving distal pancreatectomy was performed. Histopathology demonstrated granular cell tumour with cells diffusely positive for S100 and no malignant transformation. 11 case reports were identified in the literature with diagnosis confirmed on tissue histopathology based on positive immunohistochemical staining for S-100 protein. Eight patients presented with gastrointestinal symptoms with abdominal pain the main presenting complaint (50%). 10 patients underwent CT with portal venous contrast and all underwent endoscopic examination. Imaging findings were similar in five studies for EUS which demonstrated a hypoechoic lesion with homogenous appearance. On non-contrast CT GCT was iso-enhancing, and with portal venous contrast demonstrated hypo-enhancement that gradually enhanced on late phases. Pre-operative diagnosis of pancreatic carcinoma was described in six cases based on imaging and biopsy, resulting in progression to surgical resection. Nine patients were managed surgically and no complications identified on follow-up (6-52 months).
CONCLUSIONS: The currently proposed management pathway includes EUS with biopsy and CT, and surgical resection recommended due to malignancy risk. Improved sample collection with EUS-FNA and microscopic assessment utilising S-100 immunohistochemistry may improve pre-operative diagnosis. Limitations include rare numbers in reported literature and short follow-up not allowing an assessment of GCT\'s natural history and malignancy risk. Additional cases would expand the current dataset of GCTs of the pancreas, so that surgical resection may be avoided in the future.

UNASSIGNED: Granular cell tumours (GCTs) of the tongue are a rare, soft tissue pathological entity at young ages. This case report aims to present one such case.
UNASSIGNED: A 16-year-old female patient sought treatment for a small, slow-growing, painless nodule in the dorsum of the tongue since six months. She underwent successful orthodontic treatment in recent past and is in the retention phase.
UNASSIGNED: Excisional biopsy revealed the lesion to be a GCT under histopathology.
UNASSIGNED: The patient was treated for an abnormal, small, slow-growing, painless nodule in the dorsum of the tongue.
UNASSIGNED: The patient had satisfactory esthetics and early diagnosis. The active intervention dispelled the confusion about the role of trauma and orthodontics appliance in the etiology of GCT in this particular case to the patient.
UNASSIGNED: GCT can occur at any age. Early diagnosis and corrective surgery would help to avoid late complications.

Granular cell tumours are usually benign with a 1-2% incidence of malignancy. They are less sensitive to radiotherapy and chemotherapy and are treated by surgical excision. We report a case of a malignant granular cell tumour located at the interventricular septum.

Granular cell tumours (GCTs) are rare submucosal lesions, thought to develop from Schwann cells, characterised by large polygonal cells with abundant lysosomes. The objectives of this study are to investigate whether GCTs have an antigen-presenting cell (APC) phenotype or a neural crest phenotype using immunohistochemistry and to compare expression profiles with Schwannomas. Immunoreactivity to CD68, HLA-DR, CD163, CD40 and CD11c (APC phenotype) and markers of neural crest cell (NCC) origin S100, SOX10, NSE and GAP43 in 23 cases of GCTs and 10 cases of Schwannomas were evaluated. RT-qPCR was used to identify a possible NCC developmental phenotype in 6 cases of GCTs. GAP43 was identified as a new NCC marker for GCTs, and some evidence was found for an APC phenotype from CD68 and HLA-DR immunoreactivity. RT-qPCR failed to identify an NCC developmental phenotype of GCTs, likely due to technical issues.