Pilomatrixoma: a diagnostic pitfall on fine-needle aspiration cytology of benign ‘neck metastases’

Pilomatrixoma is a benign tumour that originates from the matrix of the hair root. This rare tumour is usually managed by the dermatologists. The commonest location of this tumour is in the head and neck region; hence, it can be encountered by any doctors with interest in this area. When presented in the neck, this hard tumour may pose a diagnostic challenge. A case report of pilomatrixoma misdiagnosed as a metastatic neck disease from fine-needle aspiration cytology is presented. The mistake in the diagnosis has led to a more aggressive and high morbidity surgery than necessary. It is important that head and neck doctors be aware of this condition and includes it in the differential diagnosis of hard masses presenting in the neck

Immunohistochemical analysis of mismatch repair deficiency in colorectal cancer patients in Kuantan, Pahang

INTRODUCTION: The deficient mismatch repair (dMMR) status of colorectal cancer (CRC) is the hallmark of a defective DNA mismatch repair (MMR) system. Immunohistochemistry (IHC) indirectly detects the affected gene by the loss of its protein product. This study aimed to assess the frequency of different types of dMMR status and associate them with the clinicopathological characteristics of CRC patients diagnosed at Hospital Tengku Ampuan Afzan (HTAA) and the Sultan Ahmad Shah Medical Centre (SASMEC) using an immunohistochemical method. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded (FFPE) tissue blocks of 123 CRC cases were retrieved from the Pathology Department of HTAA and SASMEC for patients diagnosed between 1 January 2017 and 31 December 2018. IHC was performed manually using an Envision Flex Polymer detection kit (Dako) along with four primary anti-mouse antibodies (MLH1, PMS2, MSH2, and MSH6) for the MMR proteins to assess dMMR status. RESULTS: Out of 123 cases, 21 (17.07%) showed the loss of one or more MMR protein expression and were dMMR. There was no statistically significant association between pMMR (proficient Mismatch repair) and dMMR cases with regards to clinicopathological factors (age, sex, race, site of the tumour, TNM (Tumour Node Metastasis) staging, bowel wall invasion, lymph node metastasis, lymphovascular invasion, histological type, and tumour differentiation). CONCLUSION: IHC is the preferred method and most reproducible test for assessing dMMR status in CRC patients in the histopathology diagnostic laboratory

Primary thyroid lymphoma: a rare malignancy in the head and neck

Primary thyroid lymphoma is a relatively uncommon pathology of the thyroid gland that mainly occurs in elderly females. We describe a rare case of B-cell thyroid lymphoma in a young healthy male. It is an important diagnosis to be considered in patients presenting with a rapidly enlarging neck mass as its management is different from other differentiated thyroid carcinoma which require total thyroidectomy plus adjuvant radioactive iodine ablation. Our report emphasizes the need for clinical awareness leading to early detection, followed by early multidisciplinary management