Fever, hand weakness... The cause is not lung cancer, but this infection!

It is only for medical professionals to read for reference.
Not all Pancoast syndromes are caused by malignant space-occupying lesions in the upper sulcus of the lung, and the possibility of benign etiology still needs to be considered in the differential diagnosis.

When a space-occupying lesion located in the upper sulcus invades musculoskeletal, brachial plexus, cervical sympathetic nerves and other structures and causes a series of neuromuscular symptoms and signs, it is called Pancoast syndrome.

Pancoast tumor (superior sulcus lung tumor) is the most common cause of Pancoast syndrome, and the vast majority of Pancoast tumors are bronchial lung cancer.

However, not all Pancoast syndromes are caused by malignant space-occupying lesions in the upper sulcus of the lung, and the possibility of benign etiology still needs to be considered in the differential diagnosis.

Let's first look at a case published in Infection magazine by Lee KH et al.
[1].

The cause of Pancoast syndrome in a 31-year-old man was not a tumor.
This was a 31-year-old smoking man who was previously healthy.
He went to the doctor with fever (38.
4°C), pain in his left shoulder, weakness in his left hand, and paresthesia.

The doctor found that the patient's right hand grip was 46 kg, while the left hand was only 2.
5 kg.

Laboratory examination revealed that the white blood cell count rose to 22.
6×109/L, the percentage of neutrophils was 77.
9%, and the C-reactive protein rose to 17.
63 mg/dl.

Lung cancer-related tumor markers were negative.

The chest radiograph showed high-density shadows on the left lung tip.

Enhanced chest CT showed a space-occupying lesion on the left side of T1-2.

The T1 weighted phase of the thoracic MRI suggested vertebral osteomyelitis with paravertebral abscess.

The chest radiograph showed a high-density shadow of the left lung tip (circle); enhanced chest CT showed a space-occupying lesion on the left side of T1-2 (arrow) [1] Follow-up blood culture confirmed positive for Streptococcus pneumoniae (serotype 12F).

Therefore, the patient was diagnosed with Streptococcus pneumoniae vertebral osteomyelitis with paravertebral abscess and Pancoast syndrome.
After 10 weeks of antibacterial treatment, the patient's symptoms improved.
Reexamination of the thoracic MRI showed that the paravertebral abscess subsided.

T2 weighted phase of thoracic MRI: paravertebral abscess (arrow) was found on admission, and the abscess subsided during follow-up review [1] The tumorous cause of Pancoast syndrome Pancoast syndrome is a syndrome with a series of symptoms and signs as clinical manifestations, including causes Shoulder pain caused by the invasion of the chest wall and brachial plexus, Horner syndrome related to the invasion of the sympathetic chain and cervical sympathetic ganglion (ipsilateral ptosis, miosis, no sweat on the same side, sunken eyeball), ulnar nerve ( C8-T1) Muscle weakness caused by compression, sometimes accompanied by upper arm edema and subclavian vein obstruction.

The anatomy of the brachial plexus is complex, and there are many other anatomical structures around it.
MRI is the preferred method to assess the involvement of the brachial plexus.

A study showed that among 104 patients with non-traumatic brachial plexus neuropathy, radiofibrosis (31%), metastatic breast cancer (24%), and primary or metastatic lung cancer (19%) were the most common Reason [3].

Lung cancer (Pancoast tumor) is the most common cause of Pancoast syndrome.

Most Pancoast tumors are located in the periphery.
Persistent shoulder pain and upper back pain are the main symptoms of patients.
Shoulder pain may also be the first manifestation of patients, often accompanied by neurological symptoms.

The histological type of Pancoast tumor is mainly non-small cell lung cancer.

Pancoast syndrome may also be caused by other malignant or benign tumors, the latter including small cell lung cancer that occupies the upper sulcus of the lung, primary adenoid cystic carcinoma, thyroid cancer, lymphoma, metastases or benign tumors [2].

Di Stefano V and others reported a case of metastatic breast cancer with lymphadenopathy complicated by Pancoast syndrome in BMJ Case Rep.

The patient was a 54-year-old woman with breast cancer.
Despite receiving multiple systemic chemotherapy, the patient still developed and progressively enlarged posterior pectoralis, supraclavicular and subclavian lymph nodes, and gradually infiltrated the brachial plexus, lung apex, and The anterior mediastinum causes severe shoulder pain, weakness of the proximal right arm, paresthesia, and numbness of the right arm [4].

MRI showed extensive involvement of the right brachial plexus, and coronal (A) and axial (B) T1-weighted images showed enlarged lymph nodes in the upper and lower clavicle areas of the right, infiltrating and surrounding the right brachial plexus [4] Non-neoplastic Pancoast syndrome Causes of lung apex infection (abscess), inflammation, nodular pulmonary amyloidosis, and thoracic outlet syndrome involving the chest wall and surrounding structures may also cause Pancoast syndrome, which is also an important differential diagnosis of Pancoast tumor.

A literature review of 31 patients with Pancoast syndrome secondary to infection showed that [5], the average age of these patients was 42.
8 years (3 months to 67 years), and the incidence of men and women was almost equal.

The initial diagnosis of 35.
5% of patients was malignant tumor.

The median time interval from onset to diagnosis of the cause of infection is 75 days (5-730 days) [5].

It can be seen that paying attention to understanding and identifying the non-neoplastic etiology of Pancoast syndrome has important clinical significance.

The pathogens associated with Pancoast syndrome are diverse, of which 54.
8% are bacteria (Staphylococcus aureus is the most common), 25.
8% are parasites (hydatid disease), and 16.
1% are fungi (Aspergillus, Cryptococcus).

Among the most common microorganisms are Echinococcus and Staphylococcus aureus [5].

According to reports, the types of bacteria associated with Pancoast syndrome include Staphylococcus aureus, Tuberculosis, Pseudomonas, Actinomycetes, Streptococcus pneumoniae and so on.

Comet R et al.
once reported a case of Pancoast syndrome and bronchial-cutaneous fistula caused by Staphylococcus aureus infection in the BMJ sub-Journal [6].

Chest radiograph and chest CT of a 59-year-old man: an irregular hollow mass on the tip of the left lung, which forms a fistula with the posterior chest wall, paraspinal muscle edema, and gas.
[6] Suppurative infection caused by Streptococcus pneumoniae can almost occur in Any part of the body, but streptococcus pneumoniae vertebral osteomyelitis and paravertebral abscess in this patient are rare.

Therefore, clinicians should consider that the cause of Pancoast syndrome may be atypical bacterial infections or infections caused by common bacteria at atypical sites.

In summary, although Pancoast tumor is the most common cause of Pancoast syndrome, when encountering patients with Pancoast syndrome, you should also think of other malignant tumor types or benign tumors, infections (abscesses), inflammation, and nodular pulmonary starch.
Relatively rare causes such as changes.

References: [1] Lee KH, Suzuki K, Tsuru M, Takazawa A.
Pancoast's syndrome: an unusual presentation of invasive pneumococcal disease.
Infection.
2018;46(5):735-736.
doi:10.
1007/s15010-018- 1119-3[2]Villgran VD,Chakraborty RK,Cherian SV.
Pancoast Syndrome.
[Updated 2021 Mar 1].
In:StatPearls[Internet].
Treasure Island(FL):StatPearls Publishing;2021 Jan-.
Available from:https: //www.
ncbi.
nlm.
nih.
gov/books/NBK482155/[3]Wittenberg KH,Adkins MC.
MR imaging of nontraumatic brachial plexopathies:frequency and spectrum of findings.
Radiographics.
2000;20(4):1023-1032 .
doi:10.
1148/radiographics.
20.
4.
g00jl091023[4]Di Stefano V,Valdesi C,Zilli M,Peri M.
Pancoast's syndrome caused by lymph node metastasis from breast cancer.
BMJ Case Rep.
2018 Nov 28;11(1): e226793.
doi:10.
1136/bcr-2018-226793.
PMID:30567112;PMCID:PMC6301591.
[5]White HD,White BA,Boethel C,Arroliga AC.
Pancoast's syndrome secondary to infectious etiologies:a not so uncommon occurrence.
Am J Med Sci.
2011;341(4):333-336.
doi:10.
1097/MAJ.
0b013e3181fa2e2d[6]Comet R,Monteagudo M,Herranz S,Gallardo X ,Font B.
Pancoast's syndrome secondary to lung infection with cutaneous fistulisation caused by Staphylococcus aureus.
J Clin Pathol.
2006;59(9):997-998.
doi:10.
1136/jcp.
2005.
029421