Background The anal canal is a rare site for lymphoepithelial-like carcinoma (LELC) and has only been reported in two patients. LELC is an undifferentiated malignant neoplasm with lymphoid background that has been reported at various sites like salivary glands, breast etc. however very few cases have been reported in gastrointestinal (GI) tract. Case Description We report the third case of a 58-year-old female who presented with a complaint of mild constipation and rectal pressure for eight months. Endoscopic ultrasound (EUS) showed a 0.8 cm nodule at the anorectal junction which was resected. Pathology showed LELC of the anorectal junction with diffuse positivity with p16 immunostaining. Polymerase chain reaction (PCR) for human papillomavirus (HPV) was positive for high-risk HPV-16, in situ hybridization (ISH) for Epstein-Barr virus (EBV)-encoded ribonucleic acid (EBER) was negative, and there was no loss of nuclear expression of mismatch repair (MMR) proteins. Patient subsequently received chemoradiation with no evidence of residual disease on restaging scans. Conclusions The association between LELC of anal canal and viral agents such as HPV or EBV has yet to be established; however, all three cases reported to date, including our current case, were positive for high-risk HPV-16, suggesting a possible role of HPV in tumorigenesis of LELC of the anal canal.

Background: Giant cell tumour (GCT) is a primary benign, locally aggressive bone tumour. Treatment is surgical however, denosumab has been increasingly used as a treatment in recurrent or unresectable locally advanced GCT because of its effect in reducing tumour size. Denosumab treated GCT can exhibit a wide array of histopathological features resulting in diagnostic problems for pathologists. Our study aimed at identifying these histopathological features to aid pathologists in reaching a correct diagnosis. Methods: Our study included 20 patients of biopsy-proven GCT cases treated with denosumab. We received specimens for histopathological examination in our institution from January 2018 to March 2020. The demographic and clinical data of these patients were retrieved from the Health Management Information System (HMIS). The slides were retrieved and studied for histopathological changes. Results: The mean age of patients in our study was 29.5 years. There were 11 males and 9 females. Distal radius was most commonly involved bone. On histopathological examination, ovoid to spindle mononuclear stromal cells were seen. Total absence of osteoclast like giant cells was seen in 10 (50%) cases, whereas 3 (15%) cases showed a marked reduction in osteoclast like giant cells. Conclusion: Denosumab treated GCT of bone can exhibit a wide spectrum of histopathological features. Pathologists need to be mindful of these features. Correlation of histopathological findings with clinical history and radiological features is important to prevent erroneous diagnosis. Treatment history of patients with denosumab is essential as incorrect diagnosis can be made if the history of denosumab treatment is not provided.

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