Genetics and lymphoedema: a future yet to be fully discovered

Genital lymphoedema and its hidden impact: a treatment guide

Genital lymphoedema is recognised as a rare consequence of cancer surgery or its treatment, which also occurs with primary lymphoedema. Over recent years, there has been an increased understanding of the condition; however, good assessment, early recognition and effective management are crucial to prevent the progression and improve the lives of those with this condition. Treatment needs to be individualised and the psychosocial and emotional aspects of the condition need to be carefully considered to ensure that the patient can achieve successful outcomes with realistic expectations.

Dysfunction of dermal initial lymphatics of the arm and upper body quadrant causes congenital arm lymphedema

OBJECTIVE

The objective of this study was to explore the pathologic process underlying primary lymphedema.

METHODS

Twenty-seven patients with unilateral congenital arm lymphedema who visited our clinic from January 1, 2014, to May 30, 2019, were enrolled. The patients' clinical signs and the findings of indocyanine green (ICG) lymphography, skin tissue immunohistochemical staining, and whole exome sequencing of tissue and blood were evaluated.

RESULTS

Among the 27 patients, 11 were diagnosed with stage II and 16 were diagnosed with stage III lymphedema. No lymphatic vessels were visualized in the affected arm in 25 of 27 (93%) patients who underwent ICG lymphography; likewise, no lymphatics were found in the territories of axillary lymph node drainage in the trunk, irrespective of any anomalies of the axillary lymph nodes. In only two (7%) patients, an unclear lymphatic trunk gradually appeared in the dorsum of the affected hand. The number of initial lymphatics was increased in the skin specimens of all nine patients in whom lymphatics were not demonstrated by ICG lymphography. Among 14 tested patients, we found compound heterozygote variants in the PIEZO1 gene in only one (7%) patient. Two missense variants, c.4072C>T; p.Arg1358Cys and c.5033C>T; p. Ala1678Val, were identified and found to have been inherited from the father and mother, respectively. No other pathogenic or likely pathogenic variants of currently known lymphedema-related genes were identified in the remaining 13 patients. No genetic difference was found between the lymphedematous and nonedematous healthy skin tissue of the same person.

CONCLUSIONS

Segmental or regional dysfunction of the dermal initial lymphatics causes congenital arm lymphedema and may have implications for clinical treatment.

How is lymphofluoroscopy mapping altering lymphoedema management?

Lymphoedema management has evolved over many decades, but the core components of treatment remain largely unaltered, such as skin care, compression and self-lymphatic drainage. Near-infrared fluorescence lymphatic imaging (NIRFLI) offers an opportunity to enhance patient outcomes by evaluating and increasing the effectiveness of these treatment options. This is relevant when we consider the impact of this chronic condition and its endemic proportions ( Mortimer, 2014 ), while Moffatt et al (2017) suggests it is one of the biggest health risks in the Western world, due to the multiple causes, such as cancer, obesity and as a complication of an ageing population. The impact of the condition can be reduced through early identification and the risk-reduction strategies that NIRFLI can offer through greater understanding of its chronicity. The use of NIRFLI has also led to the development of a new manual lymphatic drainage technique to assist in the management of lymphoedema ( Belgrado et al, 2016 ). The aim of this article is to introduce and describe NIRFLI and its use within lymphoedema management. It will discuss use with early detection of lymphoedema and expand further, focusing on its use within the management of lymphoedema.