Unveiling Evolution of Primary Right Atrial Angiosarcoma with Intra-tumoral Aneurysm: Insights from a Longitudinal Cardiac MR Imaging

Presenting Author(s)

• 

  Manphool Singhal, MD, FSCMR

  PROFESSOR
  POSTGRADUATE INSTITUTE OF MEDICAL EDUCATION AND RESEARCH, CHANDIGARH, INDIA
  Chandigarh, Chandigarh, India

Primary Author(s)

• 

  Manphool Singhal, MD, FSCMR

  PROFESSOR
  POSTGRADUATE INSTITUTE OF MEDICAL EDUCATION AND RESEARCH, CHANDIGARH, INDIA
  Chandigarh, Chandigarh, India

Co-Author(s)

• RV

  Rajesh Vijayvergiya, MD

  Professor
  Postgraduate Institute of Medical Education and Research, Chandigarh, INDIA
  Chandigarh, Chandigarh, India
• GS

  Gopika Sri

  Junior Resident
  PGIMER Chandigarh
  Chandigarh, Chandigarh, India
• RS

  Radhika Srinivasan, MD, PhD

  Professor
  Postgraduate Institute of Medical Education and Research, Chandigarh, India, India
• PG

  Parikshaa Gupta, MD

  Additional Professor
  PGIMER CHANDIGARH, India
• UN

  Uma Nahar, MD

  Professor
  Postgraduate Institute of Medical Education and Research, Chandigarh, India, Chandigarh, India
• GP

  Gaurav Prakash, MD

  Prof
  PGIMER, Chandigarh
  Chandigarh, India
• AS

  Arun Sharma, MD

  DR
  POSTGRADUATE INSTITUTE OF MEDICAL EDUCATION AND RESEARCH, CHANDIGARH, INDIA, India

Description of Clinical Presentation: A 57-year-old male presented with complaints of recurrent, sudden-onset syncopal attacks and dyspnea for the past 4 months.

Diagnostic Techniques and Their Most Important Findings: 2D- Echocardiography (ECHO) showed massive pericardial effusion, which was therapeutically drained. Post drainage, repeat ECHO showed thickening of the free wall of the right atrium. Cardiac Magnetic Resonance Imaging (CMR) demonstrated an infiltrative lesion with lobulated margins (4.3 x 2.6 cms) in the lateral wall of the right atrium just caudal to the RA-SVC junction with extension into the inter-atrial & ventricular septum, aortic root, and LA. Mass was heterogeneous, hypointense on T1-TSE, hyperintense on T2-TSE, and showed intense post-contrast enhancement on T1-TSE. Global pericardial effusion with seen without any nodularity. Right-sided pleuro-pericardial window was created, and fluid revealed malignant cells consistent with Primary Cardiac Angiosarcoma. The patient, deemed inoperable, was treated with neoadjuvant chemotherapy (Paclitaxel, carboplatin, and radiotherapy).

Follow-up CMRI at 6 months showed an increase in size and extent of lesion with areas of necrosis (cauliflower appearance), suggesting a partial response to treatment. Succeeding CMR and biphasic Contrast Enhanced CT chest & abdomen at 1 year demonstrated a significant increase in size and extent of lesion with an intra-lesional signal void (2.2 x 2.0cms) that showed intense enhancement on first pass imaging, consistent with an intratumoral aneurysm. On late gadolinium enhancement (LGE), typical rim enhancement was seen. There were multiple lung metastases, which, on PET-CT-guided biopsy, were diagnostic of angiosarcoma metastasis.

Learning Points from this Case:

• Primary Cardiac Angiosarcoma is an aggressive malignancy that infiltrates the myocardium, pericardium, and pleura. Vascular complications like intra-tumoral aneurysms are extremely infrequent, with lethal consequences due to aneurysmal rupture.


• CMR is the imaging modality of choice that provides a clue to diagnosis and provides accurate information about the location, extent, and outcome of treatment.


• On CMR, it appears as a heterogeneous infiltrative lesion, which, when small, is iso-intense on T1- and hyperintense on T2-weighted sequences; while large lesions exhibit heterogeneous signal due to hemorrhage, necrosis, and flow voids (cauliflower appearance). Tumor exhibits intense post-contrast enhancement on T1sequences, which differentiates it from other infiltrative pathologies (tuberculosis, aspergillosis or lymphoma). On LGE, a typical rim enhancement is seen.


• A signal void within the mass should be seen with caution, not mistaken for hemorrhage. On first pass imaging, if it shows intense enhancement is diagnostic of an aneurysm.


• Cytological analysis of pericardial fluid can suggest a diagnosis, as endomyocardial or image-guided biopsy may be challenging. PET-CT or CT is for metastatic work-up and guided biopsy.

Figure 1: Panel of Cardiac MR images at diagnosis (CMR): 4-Chamber (a) SSFP (Steadfast-State-Free-Precession), (b) T2-TSE (Turbo-Spin-Echo), (c) T1-TSE (Turbo-Spin-Echo), and (d) post contrast T1-TSE images show a hypointense lobulated mass lesion in the free wall of the right atrium, that is hyperintense on T2 TSE, iso to hyperintense to myocardium on T2 TSE images (thick arrows a-d). On post-contrast T1 TSE sequence, the lesion demonstrates intense enhancement. Note the infiltrative nature of the lesion with another nodule in the lateral wall of RA (interrupted arrows in c & d) and extension into the inter-atrial & ventricular septum, aortic root, and left atrium. Note global pericardial effusion. (thin arrows in a). Follow-up post-neoadjuvant chemotherapy CMR images (after 6 months of diagnosis) (e-h) show an increase in size and extent of lesion (thick arrows), which now shows internal heterogeneity with hypo/hyper intense foci within the lesion (T1 & T2 TSE) (cauliflower appearance) (f).
Figure 2: Panel of follow-up CMR images 1 year after diagnosis. 4-Chamber (a) SSFP (Steadfast-State-Flow-Precession), (b) T2-TSE (Turbo-Spin-Echo), (c) T1-TSE (Turbo-Spin-Echo), and (d) first pass, (e) post-contrast T1-TSE, and (f) late gadolinium enhancement (LGE) images show markedly increased in size and extent of lesion (thick arrows), with a hyperintense focus on SSFP and hypointense on T1 & T2 TSE images (thin arrow in a-c). This focus demonstrates enhancement similar to aorta on first-pass images (thin arrow in d), suggesting an intra-tumoral aneurysm. The lesion shows intense and heterogeneous enhancement on post-contrast T1 TSE (e) with a thickened and enhancing inter-atrial septum. LGE image (f) shows typical peripheral rim-like enhancement.
Figure 3: a: Cellular sediment smear from the pericardial effusion showing singly scattered large atypical cells with round to irregular nuclei, coarse chromatin, variably conspicuous nucleoli, and moderate cytoplasm (May Grunwald Giemsa; 40x); b: SurePath liquid-based cytology preparation showing similar scattered large atypical cells with irregular nuclei (Papanicolaou; 100x); c: Section from the cell block showing dispersed as well as occasional aggregate of similar atypical cells (Hematoxylin & Eosin; 100x); d-f: Immunocytochemistry on the cell block showing these tumor cells to be positive for vimentin (d; 40x) and FLI1 (e; 40x), while these were negative for calretinin (f; 40x), pan-cytokeratin, and HMB-45