COVID-19 represents the greatest health challenge of modern years. The spectrum of illness comprises respiratory and non-respiratory manifestations. We report the case of an adult man with COVID-19 who presented with rhabdomyolysis as a principal extrapulmonary manifestation. Our patient presented with dyspnea, fever, and muscle pain. After a comprehensive approach, the diagnosis of COVID-19 and rhabdomyolysis was made. He developed acute kidney injury requiring renal replacement therapy without reversibility, despite optimal treatment. We performed a literature search for similar cases, discuss the potential mechanisms implied, and propose a diagnostic-therapeutic algorithm.

Sarcoidosis is a multisystemic inflammatory disease of unknown cause. It is characterized by the presence of noncaseating granuloma on a biopsy specimen. Clinical presentation varies across case report series with myriad of symptoms ranging from fever, respiratory symptoms, and skin lesions, or atypical symptoms like heart block or neurological symptoms. Hence, we report the case of a 22-year-old woman with encephalitis, a pituitary mass, and adipsic diabetes insipidus. The diagnostic approach did not end on the biopsy of the lesion, which reported noncaseating granulomas; on the contrary, it was the beginning of a path to exclude other causes of the central nervous system granulomas that ended with the diagnosis of the isolated central nervous system sarcoidosis. Also, we report the first proven association between anti-NMDA receptor antibodies and sarcoidosis.

Bckground: Takotsubo cardiomyopathy is characterized by transient regional ventricular abnormalities in the absence of coronary artery disease and is reported as a complication of COVID-19. Case Representation: It can have a diverse clinical presentation, occasionally resembling an acute coronary syndrome, and progress to acute heart failure and cardiogenic shock with an adverse effect on patients' prognosis. A high index of suspicion and a thorough diagnostic approach supported by ancillary studies like echocardiography and coronary angiography is key for an accurate diagnosis and correct medical treatment. Herein, we report a patient with severe COVID-19 who developed Takotsubo cardiomyopathy. Conclusion: We also present a detailed review of the available literature regarding the relationship between COVID-19 and Takotsubo cardiomyopathy.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by a dysregulated activation of the immune system that causes fever, cytopenias, organomegalies, and hemophagocytosis. There are infectious, neoplastic, rheumatologic, and miscellaneous causes. Rickettsioses are a neglected cause of HLH. We report a confirmed case of an immunocompetent woman in Mexico with postpartum HLH secondary to spotted fever. We did a review of the literature for search of similar cases. The association between these two diseases was found in postmortem studies, unrelated to postpartum. This diagnosis should be considered in all patients with HLH without an evident cause in areas of epidemiological risk.

Key Clinical Message: Tumor‐induced osteomalacia is a paraneoplastic syndrome characterized by renal phosphate wasting and deranged bone turnover. Clinicians should consider tumor‐induced osteomalacia in unexplained hypophosphatemia and investigate for underlying tumors. Tumor‐induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by renal phosphate wasting, which leads to deranged bone turnover. TIO is usually associated with benign mesenchymal tumors, although it has also been reported in malignant tumors. We present the case of a 56‐year‐old individual who experienced a protracted 6‐year clinical course characterized by hypophosphatemia, weakness, and kyphosis, alongside the presence of a foot tumor. Subsequently, this lesion displayed malignant behavior and was ultimately diagnosed as a high‐grade sarcoma. To date, this case is among the 10 reported cases in the literature of a mesenchymal tumor associated with TIO undergoing malignant transformation. This report underscores the importance of a comprehensive evaluation of patients with unexplained hypophosphatemia and highlights the need for diligent follow‐up to detect possible malignant transformation of the underlying tumor. Clinicians should consider TIO in the differential diagnosis of hypophosphatemia and promptly investigate for the presence of an underlying tumor, as early detection may improve the patient's prognosis.