Lymphoedema of the upper limb: a rare complication of thyroid surgery?

Abstract

A 40-year-old woman underwent an elective thyroidectomy for a non-toxic, multinodular goitre. In the early postoperative period, the patient developed a significant unilateral swelling of the right upper limb, which was subsequently confirmed to be lymphoedema. This was eventually treated successfully using liposuction and compression garment therapies. We report the case due to its rarity and present a possible explanation for such an unexpected complication based on known anatomical variations of lymphatic drainage of the upper limb.

Background

An estimated 10 000 thyroid operations are performed annually in the UK.¹ Thyroid surgery is considered to be safe and is associated with low morbidity. The potential complications are well recognised and include bleeding, damage to recurrent laryngeal or external laryngeal nerves and hypoparathyroidism. Rare complications include infection, tracheal instability and lymphatic fistulae.² We present an exceptionally rare case of unilateral upper limb lymphoedema following thyroidectomy for a toxic multinodular goitre, a complication that has never been previously reported following thyroid surgery.

Case presentation

A 40-year-old woman presented with compressive symptoms caused by non-toxic, multinodular goitre. Her medical history included non-insulin-dependent diabetes mellitus, polycystic ovarian syndrome and hypertension, but she was otherwise well. Her body mass index was 28 kg/m². She underwent a total thyroidectomy and the surgical procedure was carried out without notable complication. She was well postoperatively and was discharged 2 days following the procedure. However, within the early postoperative period her right arm became increasingly swollen.

Investigations

Initial investigations including blood tests, CT and MRI were all normal. A venogram of the right upper limb showed that there was no clot and no thrombus present in the deep venous system. A subsequent lymphoscintogram (technetium-99 m albumin nanocolloid, scanned immediately postinjection and at 30 min intervals for 4 h) demonstrated significant dermal backflow with no axillary nodal uptake on the right side, consistent with a diagnosis of lymphoedema. Lymphoscintography of the left upper limb revealed a normal pattern of lymphatic drainage. Histological analysis of the thyroidectomy specimen revealed thyroid tissue only, with no lymphatic tissue present.

Treatment

Following the diagnosis of lymphoedema, the patient underwent decongestion therapy and used continuous compressive garments. Despite this, her lymphoedema persisted and the limb continued to enlarge. She was referred to the plastic surgery team after 3 years, at which stage the limb was found to be soft and fatty on palpation, with non-pitting oedema (lymphoedema-associated adipose tissue hypertrophy). Volumetric measurements demonstrated an excess of almost 1600 mL of tissue in the right upper limb (figure 1). The patient ultimately underwent liposuction of the limb, where a total of 1550 mL of fat and 200 mL of lymph fluid was aspirated. Postoperative volumetric measurement confirmed an excess of only 130 mL (figure 2), and this reduction has been maintained with on-going use of compression garments (figure 3).

Figure 1.

Preoperative photo showing lymphoedema in right upper limb.

Figure 2.

Postoperative photo showing return to normal limb volume.

Figure 3.

Chart showing postoperative reduction of oedema (%) over time.

Outcome and follow-up

Following liposuction and a period of postoperative compression therapy, the volume of the limb returned to a level comparable to the left side, which has remained stable over 5 years of follow-up. There were no complications of liposuction and the patient is highly satisfied with her result.

Discussion

Upper limb lymphoedema following thyroid surgery is an unreported and unexpected complication. Current understanding of the lymphatic drainage of the body stems largely from the work of Sappey,³ who used mercury injections in his anatomical studies to demonstrate lymphatic channels. Owing to mercury toxicity, this method was subsequently prohibited, but modern textbooks continue to present drawings of the lymphatic system based on Sappey's work.

In the upper limb, the lymphatics are arranged in deep and superficial sets of vessels, which are eventually received by the apical group of axillary lymph nodes (via the lateral and infraclavicular groups).⁴ The apical nodes drain into the subclavian lymph trunk, which on the left drains into the thoracic duct and on the right drains into the right lymphatic duct.⁵ Many textbooks describe drainage of the right lymphatic duct into the right subclavian vein at its junction with the internal jugular vein,⁶ although various combinations with the right subclavian vein and jugular trunks exist.⁷

In addition to the initial work of Sappey, there is evidence to support the existence of various secondary lymphatic drainage pathways, termed ‘substitution pathways'.⁸ Examples of these pathways in the upper limb include the tricipital pathway (‘Caplan's pathway’), which is closely associated with the triceps muscle,⁸ and the cephalic pathway (‘Mascagni's pathway’), a superficial pathway from the forearm, crossing over the clavicle en route to the cervical chain.^{9 10} Variation in lymphatic drainage patterns has also been evidenced using modern techniques of lymphatic mapping.¹¹ This has been demonstrated in patients with cutaneous melanomas, where lymphatic drainage can be highly variable.¹²

In the present case, we suggest that the lymphoedema was secondary to thyroid surgery. It would appear that a lymphatic vessel in close proximity to the thyroid, either divided during surgery or compressed by postoperative swelling, had been responsible for drainage of the right lymphatic duct as an alterative drainage pathway.

A differential diagnosis for consideration is that of primary lymphoedema. In our case, a pre-existing abnormality of the lymphatic vessels may have been compensated such that the patient did not exhibit clinical signs prior to surgery. Following surgery, there may have been decompensation with subsequent appearance of lymphoedema clinically. However, late-onset primary lymphoedema is rare, and usually involves the lower limb.¹³ It is also possible that the patient's surgery was unrelated to this process, although the development of lymphoedema within weeks of surgery would suggest that these events are indeed linked.

Liposuction has been shown to completely or markedly reduce non-pitting extremity lymphoedema due to excess fat deposition (which has not responded to non-operative therapy) in primary and secondary lymphoedema.¹⁴ Brorson¹⁵ has developed an effective treatment protocol for the management of such patients, which is employed rigorously in our unit. Lymphoedema of the right upper limb following thyroidectomy is extremely unusual, despite the known presence of variations in lymphatic anatomy. This case serves to highlight the potential implications of rare variations in lymphatic anatomy in common surgical procedures.

Learning points.

• Upper limb lymphoedema is an extremely rare complication of thyroid surgery.

• Treatment modalities include conservative management with compression garments, surgery such as liposuction, or a combination of both.

• Several variations of lymphatic drainage exist in the upper limb, which may explain the development of lymphoedema following surgery in areas where lymphatic vessels are commonly thought to be safe.