A 44-year-old man with hyperthyroidism and no smoking history presented to his internist with 5 months of intermittent cough and hemoptysis. The patient's family history was remarkable only for non-Hodgkin's lymphoma in his father. He had a history of a 25-day exposure to a home renovation at work 2 years prior to presentation. He was treated with oral clarithromycin with no improvement in his symptoms. A chest radiograph showed bilateral nodular opacities with a left lower lobar consolidative opacity (Fig 1A, 1B); the patient underwent CT scanning of the chest, which showed areas of nodular infiltration in the lower lobes with tree-in-bud-like opacities. He was referred to a pulmonologist.

A 57-year-old woman was admitted to our hospital for an abnormal chest shadow found during routine chest radiography. She had no respiratory symptoms. Her medical history included dyslipidemia, and her surgical history included conization for cervical cancer at age 38 years. She was a social drinker and ex-smoker of approximately 10 cigarettes per day (from ages 20 to 30 years); she denied recreational drug use.

A 72-year-old woman, nonsmoker, presented with approximately 2 months of nonproductive cough. The cough was initially intermittent, occurred more regularly during bedtime, but gradually became more frequent throughout the day with no reported triggering factors. The remaining review of associated symptoms was negative; she did not complain of shortness of breath, fever, chest pain, muscle weakness, weight loss, night sweats, or fatigue. She previously had been given a prescription of butamirate syrup and decongestant nasal spray with no response. Her medical history included successfully treated papillary thyroid cancer with total thyroidectomy 4 years ago, and there was no need for further therapy. Patient was free of disease on follow up from her endocrinologist, to optimize levothyroxine treatment. Her regular prescription included statins. Her professional occupation was not related to special exposure, and she reported no alcohol consumption, illicit drug use, or any recent travel.

A 75-year-old woman was referred to the pulmonary office in January 2020 for cough and progressive worsening of shortness of breath over the years. Her medical history was significant for asthma that was diagnosed approximately 10 years earlier, when she first developed dyspnea. A pre-bronchodilator spirometry at that time showed severe airflow obstruction (Fig 1). The patient was incidentally found to have several noncalcified pulmonary nodules on a chest CT scan in 2015, which was obtained as a part of dyspnea workup. She underwent bronchoscopic evaluation with transbronchial biopsy of the largest nodule (1.6 × 1.2 cm) in the right middle lobe. She was diagnosed with low-grade neuroendocrine tumor (typical carcinoid) and had been under surveillance without any progression in the number of nodules or the size of the existing nodules. She was a lifelong nonsmoker and no family history of asthma. Over the years, she received multiple courses of systemic corticosteroids and different inhalers, without any improvement in her symptoms. The patient was frustrated by the lack of perceived benefit, and she discontinued all respiratory medications. She denied any fever, night sweats, exertional chest pain, or seasonal allergies but reported cough, wheezing, and severe exertional shortness of breath. She was unable to walk more than 20 feet at a time. She had no pets at home and did not travel outside the United States. Her only home medications were multivitamins and low-dose aspirin.

A 12-year-old girl presented with shortness of breath with exercise for 2 weeks. Her oxygen saturation was 85% during exercise. Birth and family histories were unremarkable. The girl was healthy until 7.1 years of age, when she suffered a "pneumonia" with fever, dyspnea, and hypoxemia, which diminished after a 19-day treatment with antibiotics and methylprednisolone. These symptoms relapsed 8 months later, and she was diagnosed with rapidly progressive interstitial lung disease (ILD) and a Mycoplasma pneumoniae infection. At that time, her symptoms failed to respond to a course of antibiotic therapy but resolved with IV methylprednisolone at 2.7 mg/kg/day. She remained on a tapering dose of methylprednisolone plus methotrexate for the next 18 months until withdrawal of these medications because of return of almost normal lung imaging. She had never had myalgia, muscle weakness, arthritis, rashes, mechanic's hands, Raynaud's phenomenon, dry mouth, or dry eyes.

A 65-year-old man presented with shortness of breath, gradually worsening for the previous 2 weeks, associated with dry cough, sore throat, and diarrhea. He denied fever, chills, chest pain, abdominal pain, nausea, or vomiting. He did not have any sick contacts or travel history outside of Michigan. His medical history included hypertension, diabetes mellitus, chronic kidney disease, morbid obesity, paroxysmal atrial fibrillation, and tobacco use. He was taking amiodarone, carvedilol, furosemide, pregabalin, and insulin. The patient appeared to be in mild respiratory distress. He was afebrile and had saturation at 93% on 3 L of oxygen, heart rate of 105 beats/min, BP of 145/99 mm Hg, and respiratory rate of 18 breaths/min. On auscultation, there were crackles on bilateral lung bases and chronic bilateral leg swelling with hyperpigmented changes. His WBC count was 6.0 K/cumm (3.5 to 10.6 K/cumm) with absolute lymphocyte count 0.7 K/cumm (1.0 to 3.8 K/cumm); serum creatinine was 2.81 mg/dL (0.7 to 1.3 mg/dL). He had elevated inflammatory markers (serum ferritin, C-reactive protein, lactate dehydrogenase, D-dimer, and creatinine phosphokinase). Chest radiography showed bilateral pulmonary opacities that were suggestive of multifocal pneumonia (Fig 1). Nasopharyngeal swab for SARS-CoV-2 was positive. Therapy was started with ceftriaxone, doxycycline, hydroxychloroquine, and methylprednisolone 1 mg/kg IV for 3 days. By day 3 of hospitalization, he required endotracheal intubation, vasopressor support, and continuous renal replacement. Blood cultures were negative; respiratory cultures revealed only normal oral flora, so antibiotic therapy was discontinued. On day 10, WBC count increased to 28 K/cumm, and chest radiography showed persistent bilateral opacities with left lower lobe consolidation. Repeat respiratory cultures grew Pseudomonas aeruginosa (Table 1). Antibiotic therapy with IV meropenem was started. His condition steadily improved; eventually by day 20, he was off vasopressors and was extubated. However, on day 23, he experienced significant hemoptysis that required reintubation and vasopressor support.

A 34-year-old man presented to a community hospital with fever and fatigue for 3 days and was found to be febrile and tachycardic with a cavitary pulmonary lesion and paratracheal adenopathy on CT imaging. One month before, he had presented to his primary care provider with a palmar rash; he had been diagnosed and treated for syphilis and was also diagnosed with HIV. He had a CD4 count of 106 cells/μL and an HIV viral load of 1,290,000 copies/mL. Pneumocystis prophylaxis with trimethoprim-sulfamethoxazole and antiretroviral treatment with only tenofovir and emtricitabine therapy were started 2 weeks before presentation.