2.1 Chief complaints

A 31-year-old man presented with a complaint of bilateral neck swelling, recurrent nasal congestion and purulent discharge without a known cause in November 2020. The patient presented with headache, bilateral occlusion, and hearing loss and was subsequently diagnosed with NPC (T2N2M1, stage IV) at an another hospital, but did not receive regular treatment. The specific treatments given are unknown. In May 2022, he visited our hospital for further treatment due to tumor progression.

2.2 History of present illness

A diagnosis of NPC (T2N2M1, stage IV) was made in November 2020 and the patient later presented to our hospital for treatment due to poor treatment results and tumor progression.

2.3 History of past illness

He denied a history of hypertension, diabetes, coronary heart disease and tuberculosis.

2.4 Personal and family history

The patient denied any family history of malignant tumors.

2.5 Physical examination

Physical examination revealed normal mental state, appetite, sleep, urine and feces, the Eastern Cooperative Oncology Group score was 1 and the Karnofsky performance status (PS) score was 90. The bilateral lymph nodes were enlarged to varying sizes during palpation, with a maximum diameter of about 5 cm, tenderness, and unclear boundaries; A palpable mass of approximately 2 × 2 cm was detected on the right back, which was fixed and exhibited tenderness.

2.6 Laboratory examinations

Laboratory tests confirmed positive results for EB virus DNA 11370 u/ml. Computed tomography (CT) of chest, abdominal ultrasound, urinalysis, liver and kidney function, and electrolytes identified significant abnormalities.

2.7 Imaging examinations

Magnetic resonance imaging (MRI) revealed a space-occupying lesion in the nasopharynx, invasion of the posterior nasal passage, enlarged bilateral parapharyngeal spaces and cervical lymph nodes, invasion of bilateral biceps femoris (long head), pterygoid muscles, sphenoid sinus, and cavernous sinus (Fig. 1A, B). Results of the cervical CT scan indicated that bilateral lymph nodes in the Ib, II, III, IVa, V, VIIa, and VIIb regions were enlarged, with the longest diameter in the right II and III regions being 4.5 cm, which also invaded outside the capsule (Fig. 1C). Chest CT results demonstrated that there was no lung metastasis, however, there was bone destruction in the 10th rib of the right side, indicating the possibility of metastatic tumors (Fig. 1D). Lumbar MRI detected lumbar metastasis (Fig. 1E, F).

Fig. 1

Undifferentiated and nonkeratinizing NPC with lumbar spine, ribs and back metastasis. A, B a space-occupying lesion in the nasopharynx, invasion of the posterior nasal passage, enlargement of bilateral parapharyngeal spaces and cervical lymph nodes, invasion of bilateral biceps femoris (long head), pterygoid muscles, sphenoid sinus, and cavernous sinus. C Cervical CT scan showing enlarged lymph nodes in the Ib, II, III, IVa, V, VIIa, and VIIb regions on both sides. D Chest CT indicating bone destruction in the 10th rib on the right side. E, F Lumbar MRI showing lumbar metastasis. G HE and immunological examination of CK5/6 ( +), Ki67( +), P40 ( +)

2.8 Immunological examination

Upon left nasopharyngeal biopsy, the following results were obtained: CK ( +), CK5/6 ( +), P40 ( +), Ki67 (+ , approximately 60%), P53 (20% +), CD20 (−), CD3 (−), Bc12 (−), CD10 (−), CD21 (−); Right nasopharyngeal biopsy, CK ( +), P40 ( +), CK5/6 ( +), P53 (20% +), CK7 (−); 10th rib metastasis site, CK ( +), CK5/6 ( +), P40 ( +), Ki67 (+ , approximately 70%), CK7 ( +), CD56 (−), Vim (-), P53 (40% +). Based on these findings, we suspected undifferentiated and nonkeratinizing nasopharyngeal carcinoma (Fig. 1G).