Tocilizumab is a recombinant humanized monoclonal antibody directed against the interleukin-6 (IL-6) receptor, which has been used for the treatment of rheumatoid arthritis (RA). A range of side effects have been associated with tocilizumab, with gastrointestinal perforation (GIP) being described as a rare but potentially life-threatening complication that deserves considerable attention. The authors report a case of a young male patient with a history of challenging RA who encountered a lower GIP that was associated with tocilizumab therapy. The occurrence of tocilizumab-induced GIP in this reported patient had initially posed a diagnostic dilemma, as its clinical presentation mimicked other autoimmune inflammatory and infectious diseases that are commonly associated with RA. Physicians should be aware of GIPs as a serious adverse event of tocilizumab use despite being a rare phenomenon, particularly in the era of the global pandemic of coronavirus disease 2019 (COVID-19), when this novel drug has been authorized for the management of selected patients with severe COVID-19 infection. Therefore, early recognition and timely management of GIPs would minimize potential morbidities associated with critically ill COVID-19 patients.

Acute abdomen is a common emergency condition affecting young adults, and the first consideration is usually aimed to rule out acute appendicitis in this age group. Omental fat torsion has emerged as one of the rare etiologies of acute abdomen in the younger population. It warrants serious consideration as it closely mimics acute appendicitis in its clinical presentation. Herein we report a case of omental fat torsion in a 22-year-old male patient who presented with an acute right-sided lower abdominal pain which was highly suggestive of acute appendicitis. However, the diagnostic laparoscopy revealed a normally looking appendix and terminal ileum with an infarcted omental segment on the right side of the greater omentum. A laparoscopic omentectomy and an appendectomy were performed with an uneventful postoperative recovery. The pathology report confirmed omental fat infarction and a normal appendix. This case highlights omental fat infarction as a rare etiology of acute abdomen in a young male patient.

Kaposi sarcoma (KS) is caused by human herpesvirus 8 (HHV-8). Epidemic KS is described in the human immunodeficiency virus (HIV) population with acquired immune deficiency syndrome (AIDS). It primarily affects the skin, but it may uncommonly disseminate to involve extracutaneous sites such as the gastrointestinal (GI) tract, liver, and lungs. In this case report, the authors report a 26-year-old homosexual male who was admitted with acute hypoxemic respiratory failure. He was diagnosed with an HIV infection about five months before index presentation, and he was commenced on highly active antiretroviral therapy (HAART). Physical examination was remarkable for diffuse cutaneous nodules over the lower extremities, back, and oropharynx. Chest imaging revealed diffuse bilateral infiltrates, mediastinal adenopathy, and a persistent bilateral pleural effusion. Extensive diagnostic workup was negative for underlying infectious etiology. Transbronchial biopsy demonstrated proliferated spindle cells that stained positive for HHV-8 in keeping with pulmonary KS. Skin biopsies also concurred with the diagnosis of cutaneous KS. Interestingly, the cluster of differentiation 4 (CD4) count was 647 cells/mm 3 , and HIV viral load (VL) was 500 copies/ml. This case demonstrated an atypical natural history of pulmonary KS in an HIV patient as pulmonary and disseminated mucocutaneous KS occurred with a relatively higher CD4 count (≥500 cells/mm 3 ). It also reminds pulmonologists and infectious disease specialists to consider pulmonary KS as a differential diagnosis of acute hypoxemic respiratory failure in HIV patients, even in the absence of other clinical and laboratory criteria that define the AIDS stage.

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Actinomycosis is a chronic inflammatory infectious disease that can affect various organ systems. Pulmonary actinomycosis is an exceptionally uncommon clinical occurrence that yet deserves special attention, as it closely mimics a broad spectrum of infectious and neoplastic lung pathologies. The non-specific nature of its clinical features and radiological appearances makes early diagnosis quite challenging. The authors reported a 25-year-female with poorly controlled diabetes mellitus and morbid obesity who presented with a one-week history of unilateral, right-sided, pleuritic chest pain and shortness of breath. Chest imaging revealed a suspicious right hilar soft tissue mass encasing the right upper lobe bronchus with post-obstructive atelectasis. Transbronchial biopsy revealed suppurative granulomatous inflammation, and anaerobic cultures from the bronchial tissues grew Actinomyces species that were identified using the matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) technique. A long course of penicillin-based antibiotics was employed, and follow-up imaging revealed a satisfactory response to the antimicrobial therapy. This case demonstrates that microbiological examination is imperative to accurately diagnose the etiology of suspicious lung masses in young immunocompromised hosts. It also proves the diagnostic value of the MALDI-TOF technique in the early identification of Actinomyces species.