4. Myasthenia gravis
Myasthenia gravis is an acquired disease that leads to clinical symptoms of weakness and skeletal muscle damage due to the formation of autoantibodies against nicotinic acetylcholine receptors at the neuromuscular junction. Myasthenia gravis manifest themselves in a variety of manifestations, ranging from focal esophageal dysmotic disorders to acute onset diseases that lead to respiratory paralysis and death. Paraneoplastic myasthenia gravis mainly occurs in middle-aged and elderly dogs and cats. Differential diagnosis should be made for elderly patients with these clinical symptoms.
thymoma (i.e., tumors of thymic epithelial components) and cranial mediastinal lymphoma (i.e., tumors of lymphoid tissue) are the most common causes of paraneoplastic myasthenia gravis in canines. Thymoma is related to a variety of paraneoplastic syndromes in dogs and cats (including myasthenia gravis, exfoliation dermatitis, erythema polymorpha, hypercalcemia, circulating T-cell lymphocytosis, multiple myositis, anemia, myocarditis), and is the primary cause of paraneoplastic myasthenia gravis weakness in cats. It is reported that 40% of thymoma dogs suffer from myasthenia gravis and a concurrent megaesophageal duct. Exfoliating dermatitis is more common in cats with thymoma. Peripheral lymphocytosis can occur in cats and dogs.
Diagnostic tests include chest radiography or CT to identify mass on the skull septal region. Thymoma and lymphoma are treated differently; therefore, the use of diagnostic tests (such as flow cytometry, antigen receptor rearrangement PCR, histopathology) is the key to distinguishing these differences. The observations of serum autoantibodies in patients with paraneoplastic myasthenia gravis were inconsistent.
surgery is the preferred treatment for thymoma. Intracranial mediastinal lymphoma is treated with chemotherapy, usually with glucocorticoids. Incomplete relief of myasthenia gravis occurs despite treatment of underlying diseases. Pyridine can be used to treat cholinergic crisis. Promote exercise and increase the amount of food, reduce the number of foods, and increase the frequency of food, which can help relieve clinical symptoms.
5. Estrogen hyperplasia
Estrogen hyperplasia (i.e., estrogen syndrome) can lead to a unique range of clinical symptoms in dogs. Skin lesions (such as bilateral symmetrical hair loss, skin pigmentation, and thinning of the epidermis) are common. Penile atrophy, gynecological (i.e., protruding breast tissue) and milk reduction (i.e., lactation) can be observed. Patients may have a history of cryptorchidism, and male patients with these signs should investigate the history of neutrality.
Supporting cell tumors are the most common cause of paraneoplastic hypergenesis in dogs, with 50% of dogs suffering from cryptorchidism at the same time. Irreversible and potentially fatal general cytopenia is not common, but may be a poor prognostic indicator. CBC is recommended to identify cytopenia. Abdominal ultrasound can help identify renal testicles and possible abdominal metastasis and evaluate adrenal glands.
orchiectomy is the preferred treatment for supportive cell tumor patients. Cryptochilar dogs require probing abdominal incision; clinical symptoms usually disappear within 3 months after castration. Recurrence of postoperative clinical symptoms may be an indicator of metastasis. Various diagnostic laboratories provide canine and feline adrenal corticogroups for evaluating steroid hormone levels other than cortisol, which can be used to evaluate patients with suspected sexual hormone secretion due to Sertoli cell tumors or adrenal tumors.
Conclusions
Clinical symptoms caused by paraneoplastic syndrome are usually the first indicator of the underlying tumor disease process. Understanding common paraneoplastic syndrome is crucial for early diagnosis and intervention. Clinical symptoms of paraneoplastic disease can also serve as a marker of disease control or progression and may be a valuable monitoring tool.