PD-1/PD-L1-negative tracheal mucoepidermoid carcinoma: A case report and systematic review of the literature
Background: Tracheal mucoepidermoid carcinoma is a rare form of non-small cell lung carcinoma and is defined as a tumor characterized by a combination of squamous, mucus-secreting, and intermediate cell types. This carcinoma is usually located in the lobar or segmental bronchus. Currently, surgery is the preferred treatment for this disease, which includes pneumonectomy, lobectomy, and sleeve lobectomy. Case presentation: A 50-year-old Chinese male presented with cough, shortness of breath and hemoptysis, and the effect of antibiotic therapy was not good. Subsequently, the airway occupied lesion was found by chest CT, and he was transferred to our hospital for surgical resection. Histologically, the tumor contained squamous epidermal cells, mucoepidermoid cells and intermediate cells. Immunohistochemistrically, the tumor cells were positive for p63, CK5/6, CK7 and Ki67. However, the tumor is generally negative for TTF-1 and neuroendocrine markers. The patient had no recurrence 15 months after the surgery. Conclusions: We report a rare case of mucoepidermoid carcinoma in the distal trachea in which the surgery was difficult and could not be performed like a traditional pulmonary resection. We first provide a comprehensive description of airway management and anesthesia intubation. After surgery, we reviewed the literature and found that PD-1/PD-L1 detection had never been reported in tracheal mucoepidermoid carcinoma. Therefore, we studied the PD-1/PD-L1 pathway in this patient, and the results were negative, which may indicate that potential adjuvant therapy with immune checkpoint inhibitors (ICIs) is not useful in this case.
Covid 19 pandemic has taken away millions of lives. Our understanding of this disease, till to date, is not complete. This disease has a wide variety of neurological manifestations. Acute transverse myelitis is one such rare neurological complication of Covid 19. The exact etiology is not clear. Auto immunity might be one of the possible mechanisms. We report a case of 39-year-old lady, who had recent history of high-grade fever and cough. This was followed by weakness of both legs and in- ability to pass urine. SARS-CoV-2 (PCR) from nasopharyngeal swab was positive. She was found to have features of acute non compressive myelopathy. MRI brain and MRI cervical spine with contrast was normal. MRI dorso lumbar spine with contrast was suggestive of diffuse hyper intensity of conus medullaris with contrast enhancement suggestive of conus myelitis. CSF analysis ruled out infection and autoimmune causes. She was pulsed with high dose steroids. There was some transient improvement in symptoms. Learning points: 1) Physicians should not consider Covid as a respiratory illness only. It can present with a variety of extra pulmonary manifestations. 2) Acute transverse myelitis is a rare complication of Covid 19 infection. Timely recognition and treatment can prevent permanent neurological damage and residual disability. 3) Conus myelitis might not present with classic upper motor neuron signs. Any new onset bladder dysfunction in a setting of a recent covid infection should be taken seriously and requires urgent imaging of the spine.