Reasons for misdiagnosis of nasopharyngeal carcinoma and countermeasures?
Nasopharyngeal carcinoma is more sensitive to radiotherapy and the cure rate of early stage patients can reach more than 90%, but with the progress of the disease, the efficacy decreases significantly, especially for T4N3 patients, the 5-year survival rate is only about 50%. Due to the lack of understanding of nasopharyngeal carcinoma among the general public, coupled with the fact that the clinical symptoms of nasopharyngeal carcinoma are diverse and lack characteristics, and the location of nasopharynx is hidden and not easy to examine, the misdiagnosis rate of nasopharyngeal carcinoma is high, resulting in the delayed diagnosis of nasopharyngeal carcinoma patients. In this issue, the common misdiagnosis, causes and countermeasures of nasopharyngeal cancer are explained for reference.
The most common misdiagnosis of nasopharyngeal carcinoma is “otitis media”, “rhinosinusitis” and “cervical lymphitis”, which are similar to the results of previous studies. Other misdiagnosed diseases include benign neck masses, neuralgia, cervical lymph node tuberculosis, cervical spondylosis, nasal polyps, pharyngitis, and more than 10 other diseases. Due to the diversity and complexity of clinical manifestations of nasopharyngeal cancer, it is easy to lead to misdiagnosis because of the same clinical manifestations as many common diseases such as otitis media, rhinitis and lymphadenitis.
Some patients with nasopharyngeal carcinoma have repeatedly visited the respiratory department for “hemoptysis” because of “aspirated blood”, resulting in misdiagnosis for 4 years. Tumors of lateral wall origin are most likely to compress and/or obstruct the eustachian tube, resulting in fluid accumulation in the middle ear on the affected side, but primary care physicians often overlook the “unilateral” feature and diagnose it as a common “secretory otitis media” and perform “tympanic membrane puncture”. “This led to misdiagnosis. This misdiagnosis was very obvious in this study, with a misdiagnosis rate of 71.4% for patients who presented with ear symptoms such as “tinnitus and stuffiness”, which was close to the misdiagnosis rate for patients who presented with non-nasopharyngeal specific symptoms. Further invasion of the tumor into the parapharyngeal space may involve the internal and external pterygoid muscles, the mandibular nerve and even the occlusal muscle, resulting in mouth opening disorder and numbness in the jaw area. Stomatologists often misdiagnose it as temporomandibular arthritis or temporomandibular joint dysfunction. When the tumor grows forward and causes nasal congestion, nasal runny nose or even nasal bleeding, it is often diagnosed as “rhinitis and sinusitis” without nasopharyngeal examination, and some doctors even diagnose it as “nasal tumor” when they find new nasal organisms during physical examination and perform surgery. The tumor is found to be mostly in the nasopharynx and finally diagnosed. The tumor can grow upward and invade into the skull along the rupture hole, foramen ovale and other orifices, especially the cavernous sinus area, causing neurological symptoms. The most common one is bilateral diplopia caused by abducens nerve palsy, which is obvious when viewing objects to the affected side, but normal when viewing objects in one eye. It may further cause paralysis of the talocrural nerve and the motoneurotic nerve. When the tumor invades the jugular foramen and the hypoglossal foramen posteriorly, the posterior group of cranial nerve palsy symptoms may appear, such as impaired tongue movement, tongue muscle atrophy, hoarseness and mild swallowing dysfunction. Occasionally, the tumor may involve the first spinal nerve and cause pain in the corresponding innervation area. These patients are often seen in neurology or ophthalmology, and the initial physicians rarely consider the possibility of nasopharyngeal tumor and misdiagnose it as “neuritis and neuralgia”, or even individual physicians diagnose it as intracranial tumor based on incomplete images. Therefore, to be very familiar with the anatomical structure around nasopharynx, we can know the symptoms of nasopharyngeal cancer and make effective differential diagnosis.
More than 90% of domestic nasopharyngeal carcinomas are non-keratinizing carcinomas, which are poorly differentiated and often have lymphocyte infiltration around the tumor cells. Other easily misdiagnosed tumors include anaplastic malignant melanoma, hypodifferentiated rhabdomyosarcoma, and olfactory neuroblastoma. In combination with immunohistochemical techniques and the selection of appropriate markers such as EBV markers, the diagnosis can be confirmed in the vast majority of patients.
Analysis of the causes of misdiagnosis of nasopharyngeal carcinoma Nasopharyngeal carcinoma is a very special disease with completely separated diagnosis and treatment in clinical practice. In order to find the causes of delayed diagnosis of nasopharyngeal carcinoma and improve the clinical early diagnosis rate of nasopharyngeal carcinoma, we conducted a retrospective study of 416 consecutive patients admitted to our hospital for primary treatment of nasopharyngeal carcinoma by questionnaire research.
Patient factors: The retrospective study found that the total delayed diagnosis time for the whole group of cases ranged from 0 to 60 months, with a median time of 3 months. Only 1 in 4 patients was diagnosed within 1 month of onset, and nearly 1 in 10 patients had a delay of more than 1 year. Half of the delayed diagnoses were caused by patients’ lack of awareness of the disease or by “taboo”. Some studies have suggested that the patient’s literacy and economic conditions are important factors in delayed diagnosis.
Medical factors: Studies have shown that medical factors account for half of the delayed diagnosis of nasopharyngeal carcinoma. The analysis found that the confirmation rate of initial diagnosis of nasopharyngeal cancer patients was only 52%, and 48% of patients were misdiagnosed. The reasons may be the following two: 1. Nasopharyngeal cancer has various clinical symptoms and lacks specificity, and the nasopharyngeal cavity is deep, so it cannot be detected without the help of instruments.
2. Nasopharyngeal cancer is a special “diagnosis and treatment separation” tumor, and patients are usually first diagnosed in otorhinolaryngology or head and neck surgery, while the treatment of nasopharyngeal cancer is in the head and neck radiotherapy department of oncology specialty.
Hospital level: The survey found that the initial diagnosis rate of nasopharyngeal cancer in township level hospitals is only 25%, while the initial diagnosis rate in county and district level hospitals is twice as high as that in township level hospitals, reaching 50%. The provincial and municipal hospitals can reach 64%. This phenomenon indicates that the current distribution of medical resources is uneven, and the gap between the medical level of township hospitals and higher-level hospitals is large, while the gap between county and district hospitals and provincial and municipal hospitals is not obvious.
Initial consultation departments: The departments selected by patients with nasopharyngeal cancer for initial consultation were 64% for otorhinolaryngology, 18% for surgery, 4% for neurology and 3% for internal medicine. The initial diagnosis rate varied greatly among different departments. ENT, as a specialty, has obvious professional advantages, and the initial diagnosis rate was the highest among all departments, reaching 58%. Surgery and neurology were next, with 46.1% and 37.5%, respectively. The lowest initial diagnosis rate was in internal medicine, with 16.7%, while ophthalmology was slightly better than internal medicine, with 33.3% initial diagnosis rate. Otolaryngology had the highest initial diagnosis rate, while surgery, neurology, and ophthalmology were less than 50%. This phenomenon indicates that non-specialists are not sufficiently aware of nasopharyngeal carcinoma and have obvious stereotypes in their clinical work. The diagnosis rate of otolaryngologists is only 68%, which indicates that they also have a poor understanding of the complexity and diversity of nasopharyngeal cancer symptoms. When patients are asked about their medical histories, they complain that some doctors in the initial consultation do not examine the nasopharynx seriously, but only think it is “otitis media” or “rhinitis” based on experience.
Initial symptoms: The initial symptoms and signs of nasopharyngeal carcinoma have a very important influence on the clinical judgment of doctors, because the location and size of tumor invasion sites and structures can have completely different first symptoms. As the disease progresses and more structures are involved, multiple symptoms can appear. In early stage, if the tumor is confined to the posterior parietal wall of nasopharynx, patients may have no symptoms, or they may have blood in the first sputum in the morning due to small amount of bleeding on the tumor surface. This symptom is a more specific symptom of nasopharyngeal cancer, and it is relatively easy to confirm the diagnosis by this symptom. However, this important symptom is often ignored by patients as “fire”. The complaint of blood in sputum in the morning is often equated with “hemoptysis” or “bloody sputum” without detailed medical history, and chest examinations are performed because of the lung, leading to delayed diagnosis of nasopharyngeal carcinoma.
Clinical signs: Nasopharyngeal carcinoma is usually found in the pharyngeal fossa and is prone to lymph node metastasis. Sometimes, large posterior pharyngeal lymph node metastases may appear, while the primary nasopharyngeal lesion is confined to the mucosa and only shows local mucosal thickening. In some cases, the lesion is located in the subtle expansion of the mucosal base, and the nasopharynx only shows local mucosal elevation without obvious abnormalities, which is the so-called submucosal type, and is easily misdiagnosed. If the lesion extensively involves the bones of the skull base or even intracranially, it is easy to be misdiagnosed as chordoma and other skull base tumors or intracranial tumors. In this case, referring to the imaging results, biopsy under direct vision of fiberoptic nasopharyngoscope may reduce misdiagnosis. In addition, it also happens that nasopharyngeal cancer involves intracranial area because of insufficient scanning scope, which leads to misdiagnosis.
Measures to avoid delayed diagnosis of nasopharyngeal carcinoma Aimed at the general public Strengthen popular science propaganda to make patients more aware of the symptoms and characteristics of nasopharyngeal carcinoma and the importance and reliability of radiotherapy, so that they can reduce their fear of tumors and seek timely consultation and treatment.
For medical personnel 1. Primary hospitals such as townships: Continuing medical education should be strengthened to familiarize patients with common symptoms of nasopharyngeal carcinoma such as “neck mass”, “aspiration of blood”, “unilateral tinnitus and stuffy ears”, and so on. They should also know that nasopharyngeal cancer can have non-nasopharyngeal symptoms such as “headache” and “neuralgia” as the first symptoms. Strengthen the basic skills training, and be able to use indirect nasopharyngoscope to examine the nasopharynx skillfully. For suspected patients, promptly refer them to the ENT department of higher level hospitals for further examination.
2. Non-ear, nose and throat specialists in general hospitals: Continuing medical education should be strengthened, and the differential diagnosis of symptoms such as “headache”, “neuralgia” and “neck lump” should be considered comprehensively to non-departmental diseases. The differential diagnosis of symptoms such as “headache”, “neuralgia” and “neck mass” should be fully considered to be non-departmental diseases, and timely consultation should be requested from ENT doctors of related departments.
3. Specialists of otolaryngology in general hospitals should strengthen the continuing education on anatomy, pathophysiology and development of nasopharynx, fully understand the diversity and complexity of nasopharyngeal cancer symptoms, and be familiar with the rare symptoms and differential diagnosis of nasopharyngeal cancer. At the same time, they should master the manifestations of CT and MRI of nasopharyngeal cancer and the serological significance of EBV, and promptly perform fiberoptic nasopharyngoscopy and nasopharyngeal MR and other related examinations to clarify the diagnosis.