August 2023 Medical Image of the Month: Cannonball Metastases from Metastatic Melanoma

Figure 1. Upright PA chest radiograph (A) demonstrates innumerable rounded nodules with a slight lower lung predilection. Coronal reconstruction from a subsequent chest CT with contrast (B) confirms innumerable round, solid and non-calcified pulmonary nodules most consistent with a “cannonball” pattern of pulmonary metastatic disease.

Figure 2. Axial susceptibility-weighted (A) and pre-contrast T1-weighted (B) images from a brain MRI centered on one (of many) intracranial lesions. This lesion in the posterior right cerebral hemisphere demonstrates a large amount of surrounding susceptibility artifact (A) consistent with blood product, indicating a hemorrhagic metastasis, common in metastatic melanoma which can be very vascular in nature.  There is elevated T1 signal surrounding the lesion (B), also consistent with hemorrhage. There is T1 signal in the center of the lesion as well (arrow), which could represent hemorrhage but could also represent melanin, which is T1 bright and can suggest the primary tumor histology (melanoma).

A 48-year-old man with a significant smoking history presented with progressive dyspnea, a mildly productive cough with brown-tinged sputum, headache, weight loss, and progressive back pain over a period of 8 weeks. The patient had no known history of lung conditions. As part of their initial evaluation, the patient received a frontal CXR and was found to have innumerable rounded pulmonary nodules throughout the lungs, which were consistent with a “cannonball” pattern of pulmonary metastatic disease (Figure 1A). A subsequent CT confirmed innumerable pulmonary metastases (Figure 1B). An MRI of the brain and spine revealed hemorrhagic brain metastases (Figure 2), spinal metastases, and bone metastases. A biopsy of a lesion in the left iliac bone confirmed the diagnosis of metastatic melanoma.

This case highlights the so-called “cannonball” pattern of pulmonary metastatic disease with innumerable round nodules throughout the lungs with a slight lower lung predilection, consistent with a hematogenous spread of disease to the lungs. Classically, this pattern consists of numerous well-circumscribed relatively large lesions in the lungs with a pattern resembling multiple small "cannonballs". The distribution of nodules is random, and the factors that distinguish a cannonball pattern from a miliary pattern of pulmonary metastatic disease are that cannonball metastases are larger and less numerous compared to a miliary pattern of pulmonary metastatic disease (1,2). Although cannonball pattern of pulmonary metastatic disease is classically described in the setting of metastatic renal cell carcinoma, prostate cancer, choriocarcinoma, and sarcoma, it has been reported for a variety of other primary cancers, including melanoma. Similar cases of late-stage metastatic melanoma presenting as widely metastatic disease of unknown origin has also been reported (3).

Melanoma spreads to the lungs through hematogenous dissemination, resulting in the cannonball (or miliary) lesions observed on imaging. Specifically, when these lesions are small and distributed throughout the lung, they commonly indicate metastatic melanoma. While this classical presentation can be pathognomonic, it is important to consider other potential diagnoses, including malignancy, infectious diseases, and rheumatologic conditions. Malignant causes encompass metastatic colorectal cancer, breast cancer, renal cell carcinoma, choriocarcinoma, prostate carcinoma, and adrenal carcinoma. Additionally, non-cancerous causes include infectious etiologies such as septic emboli, coccidiomycosis, histoplasmosis, miliary tuberculosis, and nocardiosis. It is also important to note that rheumatologic conditions like granulomatosis with polyangiitis (Wegener's granulomatosis) can present with the cannonball sign; however, they typically involve both the upper and lower lungs. In this case, the lesions were determined to be due to metastatic melanoma, which had spread to the lungs via hematogenous dissemination.

For this patient, an oncologist was consulted, who recommended that the patient undergo treatment with ipilimumab and nivolumab. The response rate for this treatment regimen generally exceeds 50%, and more than 50% of individuals continue to survive after 5 years. Frequently, when extensive metastases are observed on imaging, healthcare providers often assume a limited life expectancy and tend to lean towards discussions of hospice care. However, it is important to keep in mind that even in cases of extensive metastatic disease, many cancers can be effectively treated with novel and highly effective immunologic anticancer medications.

Andrew Barsoum MD, Mueez Hussain MD, Ranjit Sivanandham MD, and Sina Bagheri MD.

Southwest Healthcare System

Murrieta, California 

References

1. Ammannagari N, Polu V. 'Cannon ball' pulmonary metastases. BMJ Case Rep. 2013 Jan 8;2013:bcr2012008158. [CrossRef][PubMed]
2. Andreu J, Mauleón S, Pallisa E, Majó J, Martinez-Rodriguez M, Cáceres J. Miliary lung disease revisited. Curr Probl Diagn Radiol. 2002 Sep-Oct;31(5):189-97. [PubMed]
3. Lowe A, Bray JJH. Late-stage melanoma presenting with cannonball metastases. BMJ Case Rep. 2020 Dec 12;13(12):e237969. [CrossRef][PubMed]

Cite as: Barsoum A, Hussain M, Sivanandham R, Bagheri S. August 2023 Medical Image of the Month: Cannonball Metastases from Metastatic Melanoma. Southwest J Pulm Crit Care Sleep. 2023;27(2):23-25. doi: https://doi.org/10.13175/swjpccs025-23 PDF

Medical Image of the Month: Metastatic Spindle Cell Carcinoma of the Breast

Figure 1. A coronal reconstruction of the patient’s CT of the chest with contrast in lung windows demonstrates extensive, bilateral metastatic disease, with the greatest burden of disease situated in the right lower lobe. Areas of cystic change (blue arrows) and cavitary disease (red arrow) are present.

Clinical Scenario: A 71-year-old woman with primary malignancy of the breast in remission post bilateral mastectomy in 2005 and 2008, presented to the emergency room with progressive shortness of breath for the past 6 months. Upon arrival to the emergency room, she described localized sharp chest pain along the right thoracic wall which had gradually worsened over the past three months. The pain was exacerbated with movement and with deep inspiration. She also endorsed significant hemoptysis, expectorating approximately 500 ml of bloody sputum on the morning of her presentation. Pertinent vitals revealed that she was both tachycardic and tachypneic, saturating 94% on room air with an increased work of breathing. Physical examination was significant for coarse breath sounds and diminished right sided lung sounds. Initial labs demonstrated a normal troponin and an unremarkable EKG. A chest radiograph demonstrated a large left mediastinal and hilar mass with numerous parenchymal nodules bilaterally. A CT of the chest with contrast (Figure 1) demonstrated widespread lung nodules, most notably in the right lung with a confluent mass in the right base. No significant focal lesions were seen in the chest wall or breast regions. A biopsy of the left mediastinal mass was performed and confirmed metastatic spindle cell carcinoma originating from her primary breast cancer.

Discussion: Spindle cell carcinoma of the breast, a variant classified under metaplastic carcinoma, is a rare entity occurring in less than 1% of all incidences of primary breast cancer, and most commonly seen in postmenopausal women (2,5). Treatment is primarily surgical resection. The role of radiation and chemotherapy is unclear and varies per patient treatment plan. Tumors are typically triple-negative, limiting therapeutic options (1,2,5). Primary tumor diameter and grade may be the most important prognostic factors, although prognosis regarding spindle cell carcinoma is generally poor. At the time of diagnosis, incidence of axillary lymph node metastasis was 40 – 56% with a high grade of recurrence at 57% - 63% (1,4,5). Most common extra nodal metastasis was to the lungs. In addition to the poor prognosis of spindle cell carcinomas and high rates of local recurrence, metastatic disease is also frequently seeing in patients, such as the metastatic disease seen with our patient (2-4).

Our patient’s primary breast cancer was treated with a bilateral mastectomy followed by neither chemotherapy nor radiation therapy based on patient’s preference and discussion with her oncology team. The primary tumor was in the left breast with recurrence to the right breast and metastasis to bilateral lungs. Like other cases, a biopsy revealed a triple-negative tumor. She was discharged on supplemental oxygen and is expected to receive P13K inhibitor therapy for targeted palliative treatment.

Vinita Kusupati MD, MBA and Stefano Natali DO

Department of Internal Medicine,

Banner University Medical Center-Tucson Campus

Tucson, AZ USA

References

1. Adem C, Reynolds C, Ingle JN, Nascimento AG. Primary breast sarcoma: clinicopathologic series from the Mayo Clinic and review of the literature. Br J Cancer. 2004 Jul 19;91(2):237-41. [CrossRef] [PubMed]
2. Alaoui M'hamdi H, Abbad F, Rais H, Asmouki H, Soumani A, Khouchani M, Belbaraka R. Rare variant of metaplastic carcinoma of the breast: a case report and review of the literature. J Med Case Rep. 2018 Feb 21;12(1):43. [CrossRef] [PubMed]
3. Carter MR, Hornick JL, Lester S, Fletcher CD. Spindle cell (sarcomatoid) carcinoma of the breast: a clinicopathologic and immunohistochemical analysis of 29 cases. Am J Surg Pathol. 2006 Mar;30(3):300-9. [CrossRef] [PubMed]
4. Khan HN, Wyld L, Dunne B, Lee AH, Pinder SE, Evans AJ, Robertson JF. Spindle cell carcinoma of the breast: a case series of a rare histological subtype. Eur J Surg Oncol. 2003 Sep;29(7):600-3. [CrossRef] [PubMed]
5. Tse GM, Tan PH, Putti TC, Lui PC, Chaiwun B, Law BK. Metaplastic carcinoma of the breast: a clinicopathological review. J Clin Pathol. 2006 Oct;59(10):1079-83. [CrossRef] [PubMed]
6. Tse GM, Tan PH, Lui PC, Putti TC. Spindle cell lesions of the breast--the pathologic differential diagnosis. Breast Cancer Res Treat. 2008 May;109(2):199-207. [CrossRef] [PubMed]

Cite as: Kusupati V, Natali S. Medical image of the month: metastatic spindle cell carcinoma of the breast. Southwest J Pulm Crit Care. 2021;22(6):114-5. doi: https://doi.org/10.13175/swjpcc021-21 PDF 

Medical Image of the Week: Remote Calvarial Renal Cell Metastases

Figure 1. Contrast enhanced axial MRI image shows the metastatic lesion in the right skull with mass effect and midline shift.

Figure 2. Coronal Image shows the extensive calvarial metastatic lesion and its mass effect.

A 57-year-old woman with past medical history significant for clear cell renal carcinoma and radical nephrectomy 9 years prior was admitted to our hospital for headache and left hemiparesis with associated numbness. Symptoms were progressive and had begun about 5 days prior to her presenting to our emergency department. Neurologic exam was significant for reduced strength in her left upper and lower extremities as well as well as sensory deficit to fine touch and vibratory sensation in her left arm. Her gait was unsteady and she was unable to ambulate without assistance. Her right calvarium was grossly enlarged and asymmetrical with softening of the underlying boney structures. 

MRI of the brain showed a 10 cm x 5 cm mass that was obliterating the calvarium and invading the dura mater (Figure 1).  There was mass effect with shift of the midline structures from right to left by approximately 6.5 mm (Figures 1 and 2). This was biopsy proven to be metastatic renal cell carcinoma. Additional smaller calvarium lesions were also seen. At least 3 and possibly 4 parenchymal metastatic deposits are seen in the left occipital lobe. Renal cell carcinoma has been well described to recur after long periods of remission, up to 33 years (1).

She was initially treated with intravenous dexamethasone with resolution of symptoms after 48 hours. Palliative radiation is being provided at this time.

Anthony Witten MD, Hem Desai MD, Ryan Wong MD and Joao Ferreira MD

Department of Internal Medicine

University of Arizona College of Medicine

Tucson, AZ USA

Reference

1. Parada SA, Franklin JM, Uribe PS, Manoso MW. Renal cell carcinoma metastases to bone after a 33-year remission. Orthopedics. 2009 Jun;32(6):446. [CrossRef] [PubMed]

Cite as: Witten A, Desai H, Wong R, Ferreira J. Medical image of the week: calvairial renal cell metastases. Southwest J Pulm Crit Care. 2016;12(1):32-3. doi: http://dx.doi.org/10.13175/swjpcc154-15 PDF