malignancy Archives - UCSD Ultrasound

Olivia Yale, Colleen Campbell

A 40-year-old male with no pertinent past medical history apart from significant cigarette use presented to the emergency department, referred from urgent care, for SOB and outside CXR concerning for a large right pleural effusion. The patient stated that over the past two months, he has had increasing SOB, coughing fits, and a 20-lb weight loss. The patient was born in Costa Rica but has lived in the United States for most of his life and is fully vaccinated. He denied any recent viral illness, recent travel, sick contacts, fever, abdominal pain, rashes, or chemical exposures. He stated that he has been smoking a pack of cigarettes a day for the past seven years and also occasionally smokes marijuana.

Vital Signs: BP 111/78, HR 96, RR 23, SpO2 94% on RA, T 98.3 F

Physical exam:
GEN: Thin, answering all questions appropriately
CV: RRR, no m/r/g, normal S1 and S2, peripheral pulses 2+ and equal in all extremities, no pedal edema
PULM: Diminished breath sounds throughout all right lung fields, mild rhonchi in the base of the left lung, no respiratory distress. Shallow breaths
EXT: No edema, no cords

Given the patient’s shortness of breath, urgent care CXR findings, and history, a bedside ultrasound was performed to further differentiate the patient’s complaint.

Figure 1. Right anterior lung/pleural ultrasound clip. Appropriate lung sliding (“ants marching in a line”), so less concern for pneumothorax. Multiple pleural line irregularities seen.

**Figure 2.** Right anterior lung/pleural ultrasound labeled. Notable pleural line irregularities.

Figure 3. Right posterior lung ultrasound clip for pocket evaluation prior to bedside thoracentesis. Large pleural effusion seen.

**Figure 4.** Near-complete opacification of the right hemithorax with small area of aeration in the right upper lobe. Nodular opacities scattered throughout the bilateral lungs which raise concern for large right-sided pleural effusion with severe pulmonary edema. Other etiologies not excluded.

Labs: WBC 7.5, Hb 14.3, PLT 330, Procal .04, Na 140, Cr .75, viral swab negative, lactate 1.1.

ED Course

In the ED, labs were collected (as above) and were largely unremarkable with no evidence of leukocytosis, anemia, or significant electrolyte abnormalities. After confirmation of a safe pocket with ultrasound, a bedside diagnostic and therapeutic thoracentesis was completed. After the thoracentesis, he was placed on 2L NC, but otherwise his vitals remained stable. CT chest showed a likely malignant pleural effusion and near-complete right lung collapse. He was admitted to internal medicine and was ultimately diagnosed with de novo metastatic adenocarcinoma of the lung.

Discussion

This case highlights the utility of pleural POCUS in the evaluation of lung pathology. The differential diagnosis for a young patient presenting with shortness of breath, weight loss, and a pleural effusion on outside imaging is broad, including malignancy, infection, fibrotic changes, trauma, autoimmune, and fluid overload/heart failure. However, in this patient with no prior medical conditions, no history of trauma, no fever or leukocytosis, and no other signs of fluid overload, new malignancy is of greatest concern, especially in the setting of weight loss and chronic tobacco use^1-4.

Lung POCUS is most commonly used to evaluate for a pneumothorax as part of the E-FAST exam. In this setting, the linear transducer is placed on the patient’s anterior chest, and the pleural line is evaluated for lung sliding, which is commonly referred to as “ants marching in a line”. Lung POCUS is also commonly utilized for evaluation for pleural effusions and in preparation for thoracentesis^2,5. This case highlights the importance of not only evaluating for lung sliding when doing a pleural line ultrasound, but also looking for pleural line irregularities, which are any disruption of the continuity of the pleural line, as well as for subpleural consolidations, which are small areas of lung tissue solidification just underneath the pleura. In healthy lung tissue, the pleural line is a smooth, thin (less than 3 mm), contiguous, hyperechoic line. The pleura consists of the inner visceral pleura layer that lines the lung and the outer parietal pleura that lines the chest wall, diaphragm, and mediastinum. Pleural line irregularities are seen on POCUS as fragmentation of the pleural line, often seen as “bumps”, “jaggedness”, or “dips”. The differential diagnosis for pleural line irregularities seen on POCUS includes infection (pneumonia, ARDS, TB), inflammation (post-COVID, pneumonitis), interstitial lung disease/fibrosis, and malignancy (mass, pulmonary nodules, mesothelioma). Irregularities of the pleura can also be due to subpleural consolidations caused by pneumonia, malignancy, infarction, or nodules^1,3,4,5. Although the differential for pleural irregularities seen on ultrasound is broad, in this given clinical scenario, the pleural line irregularities and subpleural consolidations seen in this patient are most likely secondary to underlying pulmonary nodules/metastatic disease in the setting of lung cancer. Ultrasound was also utilized in this case to identify a pocket for thoracentesis.

Ultrasound-guided thoracentesis is associated with substantially lower complication rates than the traditional anatomic landmark technique, particularly with respect to pneumothorax, as seen in a meta-analysis of three randomized controlled trials. In the meta-analysis, overall complications occurred in 7.4% of ultrasound-guided procedures compared with 26.0% using landmark guidance, while pneumothorax occurred in only 1.0% (1/99) of ultrasound-guided procedures versus 17.7% (20/113) with the landmark technique. Although hemorrhagic complications were too infrequent to compare (no bleeding events were reported in the single study assessing hemorrhage), the authors note that ultrasound guidance allows visualization of the diaphragm and surrounding anatomy, helping operators avoid inadvertent puncture of the intercostal artery and adjacent organs such as the liver and spleen, thereby reducing the risk of bleeding and solid-organ injury⁶.

Another prospective observational study evaluated the effectiveness and safety of real-time transthoracic ultrasound (TUS)-guided thoracentesis in 361 consecutive patients with pleural effusions. The procedure was successful in all cases, with ultrasound used continuously to visualize the needle and surrounding structures during fluid drainage. The technique demonstrated a very low complication rate, with only 3 pneumothoraces (0.83%) and no failed procedures. The authors note that traditional landmark-based thoracentesis has reported pneumothorax rates of 8.9–10.3%, whereas ultrasound-guided techniques generally reduce this to 0.97–4.9%. Real-time ultrasound guidance also helps avoid injury to adjacent structures, including the lung, diaphragm, liver, spleen, and intercostal vessels, thereby reducing the risk of bleeding and other procedural complications⁷.

Overall, lung POCUS and evaluation for pleural line irregularities are helpful in evaluating lung-related complaints and narrowing your differential diagnosis^2,3,5. Here, we demonstrate the utilization of bedside lung ultrasound, in conjunction with history and physical exam, in the evaluation and diagnosis of pleural pathologies and pleural effusions.

References

Deep Breathe. Pleural pathologies in lung ultrasound. Deep Breathe AI. Accessed June 4, 2026. https://deepbreathe.ai/blog/pleural-pathologies-lung-ultrasound
Dietrich CF, Mathis G, Cui XW, Ignee A, Hocke M, Hirche TO. Ultrasound of the pleurae and lungs. Ultrasound Med Biol. 2015;41(2):351-365. doi:10.1016/j.ultrasmedbio.2014.10.002
Volpicelli G, Elbarbary M, Blaivas M, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577-591. doi:10.1007/s00134-012-2513-4.
Boccatonda A, Cocco G, D’Ardes D, Delli Pizzi A, Vidili G, De Molo C, Vicari S, Serra C, Cipollone F, Schiavone C, et al. Infectious Pneumonia and Lung Ultrasound: A Review. Journal of Clinical Medicine. 2023; 12(4):1402. https://doi.org/10.3390/jcm12041402
Bhoil R, Ahluwalia A, Chopra R, Surya M, Bhoil S. Signs and lines in lung ultrasound. J Ultrason. 2021;21(86):e225-e233. doi:10.15557/JoU.2021.0036
Lakkadghatwala R, Wilson A, Sabhaney V, et al. Ultrasound guidance compared to anatomic landmark approach for thoracentesis: a systematic review and meta-analysis. Am J Emerg Med. 2025;97:159-164. doi:10.1016/j.ajem.2025.07.049. (sciencedirect.com)
Sperandeo M, Quarato CMI, Squatrito R, Fuso P, Dimitri L, Simeone A, Notarangelo S, Lacedonia D. Effectiveness and Safety of Real-Time Transthoracic Ultrasound-Guided Thoracentesis. Diagnostics (Basel). 2022 Mar 16;12(3):725. doi: 10.3390/diagnostics12030725. PMID: 35328278; PMCID: PMC8946970.

A 73-year-old male with a past medical history including atrial fibrillation and hypertension presented to the ED for admission for planned resection of a parotid mass with ENT. He first noted pain to his right cheek several months prior. Over this period, a mass was noted. The mass continued to grow over time, raising concern for malignancy, and the decision was made to pursue resection of the mass. On presentation, he endorsed significant pain to the right parotid area, but denied any fever, chills, chest pain, SOB, nausea, vomiting, abdominal pain, or dysuria. On physical exam, gross observation revealed diffuse swelling of the patient’s right cheek just anterior to the right tragus with marked tenderness to palpation. The remainder of his exam was unremarkable.

Point of care ultrasound was performed to visualize the mass (right side) and compare it to the contralateral, non-diseased glandular tissue (left side). The following scans were obtained:

Figure 1: Left parotid, transverse view

Figure 2: Left parotid, sagittal view

Figure 3: Right parotid with mass, transverse view

Figure 4: Right parotid with mass, sagittal view

Discussion

The parotid gland can often be elusive on account of its relatively unremarkable echogenicity. However, using anatomical landmarks, finding the gland and its surrounding structures can be quick and easy. The technique used for obtaining our bedside images for this case is summarized below:

Figure 5: Scan plane used to obtain sagittal view of the parotid

Figure 6: Scan plane used to obtain transverse view of the parotid

Figure 7: Labeled Anatomy of Parotid Gland (image from teachmeanatomy.info)

The superficial location of the parotid necessitates a high-resolution linear probe for optimal scan resolution. We found that the base of the tragus was an easy and reliable landmark to use as a starting waypoint for obtaining either the transverse or sagittal plane views. This positioning allows for identification of the parotid gland as it wraps around the angle of the mandible. The transverse plane is particularly useful for visualization of the accessory parotid gland, which is known to be the landmark for the parotid (Stenson’s) duct.^2,3 In fact, ultrasound has been shown to successfully diagnose parotid duct obstruction.4 The sagittal plane can be useful when searching for an optimal cross-section of Stenson’s duct, especially when it is dilated (e.g. in the case of an obstructing stone). Should the duct prove difficult to locate, the course and angle of Stenson’s duct may be approximated by drawing an imaginary line from the base of the tragus to the upper lip.⁵ Though we were unable to obtain optimal imaging of Stenson’s duct with this patient, we were able successfully locate the accessory parotid gland using the technique described above.

Figure 8: Left parotid gland (PG) with labeled accessory lobe (AL) noted to be just medial and separate from the main gland in the transverse plane

Overall, this case was an excellent exercise in using anatomical landmarks for localization of the parotid gland, review of notable anatomy, and comparison with diseased tissue. This patient underwent successful right superficial parotidectomy in the following days and was discharged on post-op day 1. The pathology report was concerning for high grade carcinoma with localized spread but clean margins. No lymph node involvement.

References

1. The parotid gland. TeachMeAnatomy. (n.d.). https://teachmeanatomy.info/head/organs/salivary-glands/parotid/

2. Parotid gland- normal. ULTRASOUNDPAEDIA. (n.d.) https://ultrasoundpaedia.com/parotid-gland-normal/

3. Human Anatomy Lessons. (2022, August 5). Parotid gland. Learn Human Anatomy. https://humananatomyonline.in/2022/08/05/parotid-gland/

4. Goncalves, M., Mantsopoulos, K., Schapher, M., Iro, H., & Koch, M. (2021). Ultrasound in the diagnosis of parotid duct obstruction not caused by sialolithiasis: diagnostic value in reference to direct visualization with sialendoscopy. Dentomaxillofacial Radiology, 50(3), 20200261.

5. Jones J, Howden W, Yu Y, et al. Parotid gland. Reference article, Radiopaedia.org (Accessed on 21 Sep 2023) https://doi.org/10.53347/rID-10448

This post was written by Henry Horita, Lainey Yu, MD, Ben Supat, MD, MPH, and Sukh Singh, MD. Posted by Ben Supat, MD, MPH.

Tag: malignancy

Case 77: Pleural Line Irregularities: Ultrasound in the Diagnosis of Possible Malignancy

Case 33: Parotid Mass

Discussion

References