Clinical Profile:

A 62 year old woman , resident of UP , tobacco chewer for 20 years with history of midline neck swelling since 30 years came with the complaints of increase in size of the swelling since the last two months. This has-been associated with swelling of the face, the neck and the left arm. She also has  hoarseness of voice , dyspnea and difficulty in swallowing .

On examination - The 4 cm. sized , left of midline swelling moved with deglutition. It was  hard and partially fixed. Elevation of both arms showed facial engorgement (Pemberton’s sign)

Radiological findings:

Frontal chest radiograph

● Shows soft tissue opacity in the neck on left side with deviation of trachea to the right 

● Multiple cavitatory lesions seen in both lung fields.

Ultrasound examination of the neck

● Shows a well defined, solid, iso to hypoechoeic mass measuring 6.5x3.7x6.2cm.

● The nodule is wider than taller , shows incomplete halo and both micro and macrocalcifications.

● The lesion shows both central and peripheral vascularity. It shows no spongiform/comet tail artifacts. 

● There is retrosternal extension . On elastography it is hard (Asteria ES III).

● Few necrotic lymph nodes seen in left cervical level II,III,IV.

● There is extension of this lesion into left sternocleido muscle and IJV causing complete lumen occluding thrombosis with vascularity within the thrombus.

CECT Neck and Thorax 

• shows a heterogenously enhancing mass lesion with necrotic areas and multiple calcific foci arising from left lobe of thyroid , measuring approx 5.1x6.6x7.4cm 

• Multiple enlarged necrotic lymph nodes are seen in left cervical level III, IV and V , largest  measuring 17x14mm. There is infiltration of lesion locally into left sternocleidomastoid muscle and into posterolateral wall of trachea (SHIN grade II). There is loss of fat planes with esophagus and prevertebral fascia.

• There is filling defect in the left brachiocephalic vein extending distally into the SVC and proximally into the left subclavian vein and axillary vein with increased diameter of the vessels.

• Multiple nodules seen in both lung fields , most of them are cavitatory, largest measuring 27x17mm in medial basal segment of right lower lobe. Multiple enlarged nodes seen in prevascular and paratracheal region.

Fig. 2 : Frontal chest radiograph. Soft tissue opacity in the neck on the left with shift of trachea to the right. Multiple well defined cavitary lesions in both lung fields.

Fig. 4  : CT scan of the neck . Axial ,coronal and sagital sections of the plain and contrast phases of the CT Neck shows a hetrogenously enhancing mass lesion with necrotic areas and calcifications within arising from left lobe of thyroid . Muliple enlarged lymph nodes seen in left cervical region. The lesion shows local infiltration into left SCM and posterolateral wall of trachea . Filling defect is seen in left brachiocephalic vein extending into SVC , left subclavian and axillary vein

              Figure 5: CT scan of the thorax .  Multiple nodules seen in both lung fields , most of them are cavitary with multiple enlarged nodes seen in prevascular and paratracheal region.

Radiological diagnosis:

Malignant thyroid tumor

              Figure 6: Histopathology of the lesion shows polygonal to spindle shaped cells with marked nuclear enlargement and moderate amount of cytoplasm with focal anaplastic features with increase in mitotic activity and focal areas of necrosis

Pathological diagnosis:

● FNAC of thyroid nodule shows few clusters of thyroid follicular cells with nuclear enlargement,overlapping and grooves, Bethesda category V.

● Microscopic examination of biopsy specimen shows polygonal to spindle shaped cells with marked nuclear enlargement and moderate amount of cytoplasm. It shopws focal anaplastic features with increase in mitotic activity and focal areas of necrosis.

● On immunohistochemistry , the tumor cells express AE1/AE3 , p40, PAX8 , thyroglobulin.

● Features are consistent with high grade poorly differentiated thyroid carcinoma. 

Anaplastic carcinoma with focal squamous differentiation.

Treatment :

The patient has been advised to undergo radiotherapy and chemotherapy.

Timeline :

Discussion

➢ Introduction:

Superior vena cava syndrome (SVCS) is a clinical entity characterised by signs and symptoms arising from the obstruction or occlusion of the thin-walled superior vena cava (SVC)

➢ Clinical presentation: (1)

● progressive dilatation of the veins of the upper trunk, arms, neck, and head

● increasing edema and plethora of the face, neck, upper torso, and breasts 

●   CNS disturbances with visual symptoms, syncope, dizziness, headaches, altered state of consciousness, and somnolence

●   cyanosis and conjunctival edema

●   edema of the trachea and oesophagus with respiratory distress and dysphagia. 

The Pemberton manoeuvre  is achieved by having the patient elevate both arms until they touch the sides of the face. A positive Pemberton sign is marked by the presence of facial congestion and cyanosis, as well as respiratory distress after approximately one minute.

➢ Pathophysiology (2)

● Pathogenetic basis of SVC syndrome is obstruction to the blood flow

● It can result from intrinsic  (thrombosis) or extrinsic(compression/stricture) cause

● When obstruction occurs , vascular resistance rises and venous return decreases.

● SVC pressure increases consistently

● SVC with significant stenosis - collateral circulation open up to bypass the obstruction and restore the venous return.

● In the event of SVC obstruction, there are four main routes of collateral circulation between the SVC and IVC: azygos/hemiazygos, internal mammary, vertebral, and thoracoepigastric/lateral thoracic veins. Superior intercostal and paraesophageal veins may also serve as part of the collateral circulation. 

➢ Etiology:

  ➢ Radiographic features: (3)

➔ Plain radiograph:

● Indirect signs on chest x-ray - superior mediastinal widening , right hilar prominence that may indicate the presence of mediastinal mass, shift of trachea,metastasis

● . Aortic nipple sign is also a feature. An aortic nipple is seen in about 10% of PA chest x-rays on the lateral surface of the aortic arch/aortic knob. It represents the left superior intercostal vein. When prominent, superior vena cava obstruction should be considered as the left superior intercostal vein serves as a collateral pathway (4)

➔ CT

● Is the imaging modality of choice.

● CT can define extent of blockage, illustrate collateral venous pathways, discriminate cause of obstruction.

● CT diagnosis of superior vena cava obstruction includes lack of opacification of the superior vena cava, an intraluminal filling defect or severe narrowing of the superior vena cava, and visualization of collateral vascular channels 

● Contrast enhanced CT shows the location and severity of the superior vena cava obstruction, superimposed thrombosis, a mediastinal mass or lymphadenopathy, collateral vessels, and associated lung masses.

● Grading of SVC syndrome

● Grade 0: SVC narrowing without clinical evidence of SVC syndrome

● Grade I:

■ Ia: mild SVC narrowing without collaterals

■ Ib: Moderate SVC narrowing without collaterals

● Grade II: severe SVC narrowing above the azygos with the azygos vein serving as partial collateral

● Grade III: SVC obstruction below the azygos arch

● Grade IV: SVC obstruction at the azygos arch

● A focal hepatic hot spot sign may be visible. The focal hepatic hot spot sign, also known as the hot quadrate sign can be seen on technetium 99m sulfur colloid scans of the liver and spleen, as well as CT studies. It occurs as a focal area of increased radiopharmaceutical uptake, or iodinated contrast accumulation, in the medial segment of the left hepatic lobe (segment IV). This is a pseudolesion caused by abnormal tracer or contrast accumulation due to superior vena cava obstruction (SVCO)

Radiologic stages of vena cava obstruction. :

The Stanford classification system for superior vena cava (SVC) syndrome was developed to assist in identifying patients at risk of substantial airway or cerebral compromise and therefore warranting rapid intervention.

 A: Stanford type I: mild SVC obstruction, with vessel obstruction of less than 90%. B: Stanford type II: high-grade SVC stenosis (grade of stenosis 90–100%). C: Stanford type III: complete SVC obstruction and prominent flow through collateral veins, but without involvement of the mammary and epigastric veins. D: Stanford type IV: complete SVC obstruction and prominent flow through collateral veins and the mammary and epigastric veins..

➔ Ultrasonography:

● It is useful to detect thrombosis in IJV , Subclavian vein , axillary vein , brachiocephalic vein.

● It is used for UGG guided IV access for endovascular therapy.

➔ Conventional catheter based central venography

➔ MR Venography:

In patients with iodine contrast allergy or in whom venous access cannot be obtained for conventional venography.

➢ Management:

Management of SVCS should be multidisciplinary with cooperation among different medical specialties such as radiology and interventional radiology, pulmonology, surgery, vascular surgery, and oncology. The therapeutic approach of SVCS has two pillars: to alleviate symptoms related to SVC obstruction and to treat the underlying disease.

● General Measures

Regardless of the etiology, head elevation should be the initial mainstay management in all patients because it decreases head and neck edema and hydrostatic pressure . Other general measures include the administration of glucocorticoids and loop diuretics.

● Radiation Therapy

● Chemotherapy

● Surgery

Open surgical intervention such as bypass grafting procedure plays a limited role in SVCS management. Malignant invasion is the most frequent indication for SVC resection and reconstruction. 

● Endovascular therapy (ET)

It should be considered the standard of care approach in patients with malignancy-related symptomatic SVCS and short to medium life expectancy either at initial presentation or following RT or chemotherapy.

Venography depicting extensive stenosis of the SVC together with thrombosis (left) and recanalization of the lesion with combined thromboaspiration and stent placement technique (right)

Conclusion: 

Superior vena cava obstruction is most commonly related to an underlying malignancy and can result in significant morbidity and mortality. SVCS does not represent a true oncologic emergency in the vast majority of cases; however, it necessitates prompt investigation and expedient management for occult malignancy in patients who present with unknown history of cancer. SVCS does not affect the chance of cure of the underlying malignancy and should not change the overall treatment. Management involves symptom alleviation and treatment of underlying disease and has evolved over time. 

References: 

  1) Philipp M Lepper, Sebastian R Ott, Hanno Hoppe, Christian Schumann, Uz Stammberger, Antonio Bugalho, Steffen Frese, Michael Schmücking, Norbert M Blumstein, Nicolas Diehm, Robert Bals and Jürg Hamacher

2) Radswiki T, Yap J, Vadera S, et al. Superior vena cava obstruction. Reference article, Radiopaedia.org (Accessed on 26 Jan 2023) https://doi.org/10.53347/rID-19760

3) Byerly, D.W., Schlesinger, A.E. Acquired aortic nipple: a potential sign of deep venous obstruction. Pediatr Radiol 40 (Suppl 1), 71 (2010). https://doi.org/10.1007/s00247-010-1760-1

4) Patriarcheas V, Grammoustianou M, Ptohis N, Thanou I, Kostis M, Gkiozos I, Charpidou A, Trontzas I, Syrigos N, Kotteas E, Dimakakos E. Malignant Superior Vena Cava Syndrome: State of the Art. Cureus. 2022 Jan 4;14(1):e20924. doi: 10.7759/cureus.20924. PMID: 35004083; PMCID: PMC8727327.

Acknowledgement :

We are grateful to the Department of Pathology at our institution for providing the histopathology image and its description as also the details of the final pathological diagnosis.