Summary This is a report on antithyroid arthritis syndrome (AAS) which is a rare adverse effect of antithyroid agents. AAS presents with severe symptoms including myalgia, arthralgia, arthritis, fever, and skin eruption due to the use of antithyroid agents. We encountered a 55-year-old woman with severe pain in the hand and forearm and arthralgia in multiple joints, including the knee, ankle, hand, and wrist on day 23 after initiation of methimazole (MMI) for Graves’ disease. Blood tests revealed elevated inflammation markers such as C-reactive protein and interleukin-6, and magnetic resonance imaging of the hands confirmed inflammation findings. After withdrawing MMI on day 25, symptoms showed a tendency toward improvement. Afterwards, inflammation markers also dropped to an almost normal range. In addition to the above findings, the absence of anti-neutrophil cytoplasmic antibodies and most vasculitis symptoms such as nephritis, skin, or pulmonary lesions led to the diagnosis of AAS. A resolution of symptoms, except for mild arthralgia in the second to fourth fingers of the right hand, was observed 61 days after discontinuation of MMI. Although the pathogenesis is unclear, the positive drug lymphocyte stimulation test for MMI and the several weeks before the onset of AAS suggested involvement of a type IV allergic reaction. Based on a discussion of definitive treatment for Graves’ disease, radioactive iodine ablation with 131I, which was selected by the patient, was performed and improved her thyroid function. Our case demonstrates the importance of awareness regarding AAS, which is a rare and under-recognized, but life-threatening adverse effect of antithyroid agents. Learning points Clinicians should be aware of the possibility of developing antithyroid arthritis syndrome (AAS) in patients treated with antithyroid medications, which can lead to severe migratory polyarthritis. Prompt cessation of the antithyroid agent is essential for the resolution of AAS. Anti-neutrophil cytoplasmic antibody (ANCA) negativity is needed to differentiate from antithyroid agent-induced ANCA-associated vasculitis, which shows arthritis similar to AAS.

Background Primary hypothyroidism is a known risk factor for pituitary hyperplasia, which develops symptoms due to compression of the optic chiasm and increased intracranial pressure. As pituitary hyperplasia is known to improve after levothyroxine replacement therapy, there have been no reports of a long clinical course of pituitary hyperplasia due to primary hypothyroidism. Case presentation An 18-year-old female presented with headache, double vision and bitemporal hemianopia. A large suprasellar tumor measuring 19.2X13.67X18.96 mm on MRI and the biological testing comprising low thyroid hormone and high TSH levels, and positive thyroid stimulation blocking antibody (TSBAb) were indicative of pituitary hyperplasia due to primary hypothyroidism with TSBAb. For the purpose of ruling out invasive pituitary tumors, the lower one-fourth of the pituitary gland was biopsied and histopathological examination showed pituitary hyperplasia and no malignant findings. A follow-up MRI showed dramatic shrinkage of the pituitary gland after levothyroxine replacement therapy. As pituitary gland size was monitored for approximately 16 years, it did not converge to a normal size. Conclusions We describe a case of follow-up over 16 years for pathologically diagnosed pituitary hyperplasia due to primary hypothyroidism with positive TSBAb. Repeated enlargement and shrinkage were confirmed, but observations also suggested the pituitary gland to not always return to normal size after the appearance of profound pituitary hyperplasia. The patient’s non-adherence with levothyroxine intake is likely to cause a profound pituitary enlargement, leading to symptoms due to compression of the optic chiasm and increased intracranial pressure. In the case of poor medication adherence, medication guidance is important to be provided assiduously for the prevention of profound pituitary hyperplasia, while using TSH and PRL levels as indicators.

We herein report a fatal case of invasive mucinous adenocarcinoma (IMA) with acute respiratory distress syndrome (ARDS) diagnosed based on autopsy findings. A 76-year-old man presented with severe respiratory discomfort on admission. Computed tomography (CT) revealed a peripheral distribution of consolidation. Although his respiratory status improved after steroid therapy, re-exacerbation occurred, and the patient died on day 131. A bronchoscopic lung biopsy had shown organizing pneumonia, but a post-mortem examination surprisingly revealed IMA with organizing pneumonia. IMA presenting with ARDS as the first symptom is extremely rare.