- Email: [email protected]
Redefining gigantomastia
Journal of Plastic, Reconstructive & Aesthetic Surgery (2011) 64, 160e163
Redefining gigantomastia H. Dafydd a, K.R. Roehl b, L.G. Phillips b, A. Dancey a, F. Peart a, K. Shokrollahi c,* a
Department of Burns & Plastic Surgery, Selly Oak Hospital, Birmingham B29 6JD, UK Division of Plastic Surgery, Department of Surgery, UTMB Galveston, 301 University, Galveston, TX 77555-0724, USA c Department of Plastic Surgery, L’Hoˆpital d’Ottawa, 1053 Carling Avenue, Ottawa, Ontario, K1Y 4E9, Canada b
Received 3 March 2010; accepted 23 April 2010
KEYWORDS Gigantomastia; Definition; Breast; Body mass index
Summary Gigantomastia is a rare but disabling condition characterised by excessive breast growth. Most definitions of gigantomastia refer to a particular weight of excess breast tissue. We speculate that in gigantomastia the weight of the breasts contributes significantly to the BMI, which has implications for healthcare rationing. This study aims to establish the contribution breast tissue makes to BMI in gigantomastia. In so doing, we propose a new definition of gigantomastia. Retrospective data was collected from the case notes of 68 females who underwent breast reduction or therapeutic mastectomy for gigantomastia. For the purposes of patient inclusion, gigantomastia is arbitrarily defined as excessive breast growth of over 1.5 kg per breast. The difference between pre- and post-operative BMI is statistically significant (P < 0.001). Mean pre-operative BMI is 38.7 with a mean specimen weight of 4506 g. Mean contribution of specimen to body weight is 4.29%. There is no correlation between pre-operative body weight and the percentage contribution the breast resection specimen makes to body weight. Based on our data, we define gigantomastia as excess breast tissue that contributes 3% or more to the patient’s total body weight, approximately one standard deviation below the mean. We suggest that the estimated excess breast tissue weight is taken into account when calculating pre-operative BMI in the gigantomastia population. The challenge of estimating excess breast weight pre-operatively may be met by 3D photography coupled with computer-assisted volumetry. ª 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Tel.: þ1 613 722 7000. E-mail address: [email protected] (K. Shokrollahi). 1748-6815/$ - see front matter ª 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2010.04.043
Redefining gigantomastia Gigantomastia is a rare but disabling condition characterised by excessive breast growth. There is no universally accepted definition of gigantomastia, but the majority of citations refer to a particular weight of excess breast tissue.1,2 Most agree that the mainstay of treatment for gigantomastia is surgical, in the form of reduction mammaplasty or mastectomy, with or without hormonal therapy.3 The availability of reduction mammaplasty is frequently rationed by third party fundholders internationally, based on the body mass index (BMI) of patients.4 Many patients who are denied a breast reduction on this basis believe the mass of their breasts is contributing significantly to their elevated BMI. In practice we have found that this contribution is usually not significant, with a breast reduction specimen contributing a mean of 0.5 BMI points, although in isolated cases it can be greater than 1.5 However we speculate that in cases of gigantomastia where there is breast hypertrophy out of proportion to the BMI, the contribution of breast tissue to the BMI is more significant. We undertook this study to establish the contribution that resected breast tissue makes to patients’ BMI who are undergoing breast reduction or therapeutic mastectomy for gigantomastia. Due to the relatively low incidence of gigantomastia, this study involved collaboration between units in the UK and USA. Based on our data series, we propose a new definition of gigantomastia.
Patients and methods Data was collected retrospectively from the case notes of 68 females who underwent a breast reduction or therapeutic mastectomy for gigantomastia using collated data from the UK and USA. For the purposes of patient inclusion, gigantomastia is arbitrarily defined as excessive breast growth of over 1.5 kg per breast, which is popular with many authors.3 We included patients who had more than 1.5 kg removed from at least one breast. Patient height, pre-operative weight, pre-operative BMI and weight of the resected breast tissue were recorded. This allowed calculation of the projected post-operative weight and BMI by subtracting the weight of the resected breast tissue from the patient’s pre-operative weight. The mean, standard deviation (SD), paired t-test and the coefficient of determination r2 are calculated using the AVERAGE, STDEVA, TTEST and RSQ functions of Microsoft Excel 2008 for Mac respectively.
161 Table 1
Data summary showing mean SD
Pre-operative BMI (kg/m2) Weight of specimen e both breasts (g) Calculated post-operative BMI (kg/m2) Contribution of specimen to body weight (%)
38.7 7.29 4506.4 1845.4 37.0 6.97 4.29 1.37
specimen makes to body weight (Figure 2), there is no correlation (r2 Z 0.00).
Discussion Patients who are turned down for breast reduction surgery on the basis of their BMI frequently argue that the weight of their breasts is contributing significantly to their body weight. It has been shown that for the majority of women undergoing reduction mammaplasty with an average combined resection weight of 1.2 kg the reduction in BMI achieved post-operatively is not statistically significant, amounting to an average decrease of 0.48 BMI points.5 However, a clinically significant reduction in BMI was seen in short, slim patients with large resection weights of greater than 1 kg per breast. We have now examined in detail the relationship between BMI and resection weights in the gigantomastia population to assess whether withholding reduction mammaplasty on the basis of BMI is justified for these patients. Our results show that in gigantomastia, the contribution a breast reduction specimen makes to a patient’s body weight is statistically significant. On this basis, it would be fair to estimate the expected weight of the resection specimen pre-operatively and factor this into the calculation of the BMI. The lack of correlation between total body weight and the percentage contribution the resection specimen makes to body weight is striking. It may be argued that women requesting treatment for gigantomastia whose BMIs fall above the upper limit set by healthcare fundholders have large breasts because they are obese. However, Figure 2 shows that this is not the case. As BMI increases, the breasts of patients with gigantomastia
Results The results are summarised in Table 1. Data is presented as mean SD. The difference between pre- and post-operative BMI is statistically significant (P < 0.001). The largest contribution a breast reduction specimen makes to a patient’s body weight is 8.41%, seen in a patient with a pre-operative body weight of 89.8 kg, BMI 40.0 and resection weight of 7550 g. The relationship between patients’ pre-operative body weight and weight of the resection specimen is plotted in Figure 1. As might be expected, there is a positive correlation between the two (r2 Z 0.29). However, when pre-operative body weight is plotted against the percentage contribution the resection
Figure 1 Scatter plot with linear regression line showing patient body weight (kilograms) against weight of breast resection specimen (grams).
162
Figure 2 Scatter plot with linear regression line showing patient body weight (kilograms) against the percentage contribution a breast resection specimen makes to body weight (%).
remain out of proportion to their BMI to the same degree as for women with normal BMIs. This raises many issues regarding withholding reduction mammaplasty in the gigantomastia population on the grounds of BMI alone. Obese women will suffer from the effects of gigantomastia in the same way as those with a ‘normal’ BMI, and it has been shown that symptoms of macromastia are not usually alleviated by weight loss.6 Other studies conclude that most patients with symptomatic large breasts benefit from reduction mammaplasty irrespective of their BMI.7 One of those studies showed a correlation between obesity and benefits of reduction mammaplasty: the most obese had most benefit in terms of improved lung function, quality of life and psychosocial status.8 The application of arbitrary and absolute BMI limits to breast reduction surgery is therefore not reasoned or justifiable in the context of gigantomastia. So should we be abandoning the BMI altogether? It is by no means a perfect measure of obesity since athletic or muscular individuals may register as obese despite having low total body fat and excellent fitness.9 Given that the weight of breasts in gigantomastia contribute significantly to the BMI, it would be prudent to consider softening the absolute BMI limits imposed by rationing bodies in these cases. However, we should not lose sight of the usefulness of the BMI, flawed though it is. If we are proposing operating on patients with gigantomastia whose BMIs are greater than 30, we must also be aware of the potential risks of doing so. Obesity is associated with a number of medical conditions such as diabetes, hypertension and increases the risk of general anaesthesia.10 Although most post-operative complications in obese patient groups are limited to minor wound healing problems, these complications become more clinically significant with BMIs over 40.11 Based on our data, it is reasonable to define gigantomastia as excess breast tissue that contributes 3% or more to the patient’s total body weight. This figure is approximately one standard deviation below the mean contribution a resection specimen makes to body weight in our series of 68 women. Applying a definition such as this to breast size means that the short, slim patient with
H. Dafydd et al. extremely large breasts that may not reach 1.5 kg in weight is now more appropriately diagnosed as having gigantomastia. Conversely, the centrally obese patient whose breasts have ‘grown with her’, proportionately, to over 1.5 kg each in weight will no longer be defined as gigantomastia. We have shown that the weight of the resection specimen in gigantomastia contributes significantly to the patient’s BMI. It is proposed that gigantomastia should be defined as excess breast tissue that contributes >3% of the patient’s total body weight. For the purposes of pre-operative assessment in the gigantomastia population, we suggest an adjustment is made to the patient’s BMI based on the estimated excess breast tissue weight. However we make clear that our new definition of gigantomastia is, by necessity, retrospective. The major clinical problem now faced by surgeons is how to accurately estimate the weight of excess breast tissue prospectively. Measuring pre-operative breast weight clinically is usually an inaccurate, subjective estimate. It may be that hospital clinical photography departments can be of assistance here. Photography studios with a 3D camera set up or laser body scanner can rapidly capture a patient’s body map. A computer can extract hundreds of measurements from this data to calculate the breast volume.12 Breast weight is derived by multiplying breast volume with the density of breast tissue. This will vary from person to person depending on the composition of the individual’s breasts, but will be approximately 1 g/cm3 (given that fat is hypodense and blood is hyperdense relative to water). This method could yield a more accurate and reproducible measure of pre-operative breast weight. When coupled with the patient’s body weight, it would allow for a preoperative diagnosis of gigantomastia to be made according to our new definition.
Conflict of interest statement None.
Funding None.
References 1. Lacerna M, Spears J, Mitra A, et al. Avoiding free nipple grafts during reduction mammaplasty in patients with gigantomastia. Ann Plast Surg 2005;55:21e4. 2. Slezak S, Dellon AL. Quantitation of sensibility in gigantomastia and alteration following reduction mammaplasty. Plast Reconstr Surg 1993;91:1265e9. 3. Dancey A, Khan M, Dawson J, et al. Gigantomastia e a classification and review of the literature. J Plast Reconstr Aesthet Surg 2008;61:493e502. 4. NHS Modernisation Agency. Information for Commissioners of Plastic Surgery Services. Referrals and Guidelines in Plastic Surgery. 2005. 5. Dafydd H, Juma A, Meyers P, et al. The contribution of breast and abdominal pannus weight to body mass index: implications for rationing of reduction mammaplasty and abdominoplasty. Ann Plast Surg 2009;62:244e5.
Redefining gigantomastia 6. Collins ED, Kerrigan CL, Kim M, et al. The effectiveness of surgical and nonsurgical interventions in relieving the symptoms of macromastia. Plast Reconstr Surg 2002;109:1556e66. 7. Atterhem H, Holmner S, Janson PE. Reduction mammaplasty: symptoms, complications, and late results. A retrospective study on 242 patients. Scand J Plast Reconstr Surg Hand Surg 1998;32:281e6. 8. Sood R, Mount DL, Coleman JJ, et al. Effects of reduction mammaplasty on pulmonary function and symptoms of macromastia. Plast Reconstr Surg 2003;111:688e94.
163 9. Pounder D, Carson D, Davison M, et al. Evaluation of indices of obesity in men: descriptive study. BMJ 1998;316:1428e9. 10. Adams JP, Murphy PG. Obesity in anaesthesia and intensive care. Br J Anaesth 2000;85:91e108. 11. Wagner DS, Alfonso DR. The influence of obesity and volume of resection on success in reduction mammaplasty: an outcomes study. Plast Reconstr Surg 2005;115:1034e8. 12. Wells JC, Ruto A, Treleaven P. Whole-body three-dimensional photonic scanning: a new technique for obesity research and clinical practice. Int J Obes (Lond) 2008;32:232e8.
Redefining gigantomastia H. Dafydd a, K.R. Roehl b, L.G. Phillips b, A. Dancey a, F. Peart a, K. Shokrollahi c,* a
Department of Burns & Plastic Surgery, Selly Oak Hospital, Birmingham B29 6JD, UK Division of Plastic Surgery, Department of Surgery, UTMB Galveston, 301 University, Galveston, TX 77555-0724, USA c Department of Plastic Surgery, L’Hoˆpital d’Ottawa, 1053 Carling Avenue, Ottawa, Ontario, K1Y 4E9, Canada b
Received 3 March 2010; accepted 23 April 2010
KEYWORDS Gigantomastia; Definition; Breast; Body mass index
Summary Gigantomastia is a rare but disabling condition characterised by excessive breast growth. Most definitions of gigantomastia refer to a particular weight of excess breast tissue. We speculate that in gigantomastia the weight of the breasts contributes significantly to the BMI, which has implications for healthcare rationing. This study aims to establish the contribution breast tissue makes to BMI in gigantomastia. In so doing, we propose a new definition of gigantomastia. Retrospective data was collected from the case notes of 68 females who underwent breast reduction or therapeutic mastectomy for gigantomastia. For the purposes of patient inclusion, gigantomastia is arbitrarily defined as excessive breast growth of over 1.5 kg per breast. The difference between pre- and post-operative BMI is statistically significant (P < 0.001). Mean pre-operative BMI is 38.7 with a mean specimen weight of 4506 g. Mean contribution of specimen to body weight is 4.29%. There is no correlation between pre-operative body weight and the percentage contribution the breast resection specimen makes to body weight. Based on our data, we define gigantomastia as excess breast tissue that contributes 3% or more to the patient’s total body weight, approximately one standard deviation below the mean. We suggest that the estimated excess breast tissue weight is taken into account when calculating pre-operative BMI in the gigantomastia population. The challenge of estimating excess breast weight pre-operatively may be met by 3D photography coupled with computer-assisted volumetry. ª 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Tel.: þ1 613 722 7000. E-mail address: [email protected] (K. Shokrollahi). 1748-6815/$ - see front matter ª 2010 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2010.04.043
Redefining gigantomastia Gigantomastia is a rare but disabling condition characterised by excessive breast growth. There is no universally accepted definition of gigantomastia, but the majority of citations refer to a particular weight of excess breast tissue.1,2 Most agree that the mainstay of treatment for gigantomastia is surgical, in the form of reduction mammaplasty or mastectomy, with or without hormonal therapy.3 The availability of reduction mammaplasty is frequently rationed by third party fundholders internationally, based on the body mass index (BMI) of patients.4 Many patients who are denied a breast reduction on this basis believe the mass of their breasts is contributing significantly to their elevated BMI. In practice we have found that this contribution is usually not significant, with a breast reduction specimen contributing a mean of 0.5 BMI points, although in isolated cases it can be greater than 1.5 However we speculate that in cases of gigantomastia where there is breast hypertrophy out of proportion to the BMI, the contribution of breast tissue to the BMI is more significant. We undertook this study to establish the contribution that resected breast tissue makes to patients’ BMI who are undergoing breast reduction or therapeutic mastectomy for gigantomastia. Due to the relatively low incidence of gigantomastia, this study involved collaboration between units in the UK and USA. Based on our data series, we propose a new definition of gigantomastia.
Patients and methods Data was collected retrospectively from the case notes of 68 females who underwent a breast reduction or therapeutic mastectomy for gigantomastia using collated data from the UK and USA. For the purposes of patient inclusion, gigantomastia is arbitrarily defined as excessive breast growth of over 1.5 kg per breast, which is popular with many authors.3 We included patients who had more than 1.5 kg removed from at least one breast. Patient height, pre-operative weight, pre-operative BMI and weight of the resected breast tissue were recorded. This allowed calculation of the projected post-operative weight and BMI by subtracting the weight of the resected breast tissue from the patient’s pre-operative weight. The mean, standard deviation (SD), paired t-test and the coefficient of determination r2 are calculated using the AVERAGE, STDEVA, TTEST and RSQ functions of Microsoft Excel 2008 for Mac respectively.
161 Table 1
Data summary showing mean SD
Pre-operative BMI (kg/m2) Weight of specimen e both breasts (g) Calculated post-operative BMI (kg/m2) Contribution of specimen to body weight (%)
38.7 7.29 4506.4 1845.4 37.0 6.97 4.29 1.37
specimen makes to body weight (Figure 2), there is no correlation (r2 Z 0.00).
Discussion Patients who are turned down for breast reduction surgery on the basis of their BMI frequently argue that the weight of their breasts is contributing significantly to their body weight. It has been shown that for the majority of women undergoing reduction mammaplasty with an average combined resection weight of 1.2 kg the reduction in BMI achieved post-operatively is not statistically significant, amounting to an average decrease of 0.48 BMI points.5 However, a clinically significant reduction in BMI was seen in short, slim patients with large resection weights of greater than 1 kg per breast. We have now examined in detail the relationship between BMI and resection weights in the gigantomastia population to assess whether withholding reduction mammaplasty on the basis of BMI is justified for these patients. Our results show that in gigantomastia, the contribution a breast reduction specimen makes to a patient’s body weight is statistically significant. On this basis, it would be fair to estimate the expected weight of the resection specimen pre-operatively and factor this into the calculation of the BMI. The lack of correlation between total body weight and the percentage contribution the resection specimen makes to body weight is striking. It may be argued that women requesting treatment for gigantomastia whose BMIs fall above the upper limit set by healthcare fundholders have large breasts because they are obese. However, Figure 2 shows that this is not the case. As BMI increases, the breasts of patients with gigantomastia
Results The results are summarised in Table 1. Data is presented as mean SD. The difference between pre- and post-operative BMI is statistically significant (P < 0.001). The largest contribution a breast reduction specimen makes to a patient’s body weight is 8.41%, seen in a patient with a pre-operative body weight of 89.8 kg, BMI 40.0 and resection weight of 7550 g. The relationship between patients’ pre-operative body weight and weight of the resection specimen is plotted in Figure 1. As might be expected, there is a positive correlation between the two (r2 Z 0.29). However, when pre-operative body weight is plotted against the percentage contribution the resection
Figure 1 Scatter plot with linear regression line showing patient body weight (kilograms) against weight of breast resection specimen (grams).
162
Figure 2 Scatter plot with linear regression line showing patient body weight (kilograms) against the percentage contribution a breast resection specimen makes to body weight (%).
remain out of proportion to their BMI to the same degree as for women with normal BMIs. This raises many issues regarding withholding reduction mammaplasty in the gigantomastia population on the grounds of BMI alone. Obese women will suffer from the effects of gigantomastia in the same way as those with a ‘normal’ BMI, and it has been shown that symptoms of macromastia are not usually alleviated by weight loss.6 Other studies conclude that most patients with symptomatic large breasts benefit from reduction mammaplasty irrespective of their BMI.7 One of those studies showed a correlation between obesity and benefits of reduction mammaplasty: the most obese had most benefit in terms of improved lung function, quality of life and psychosocial status.8 The application of arbitrary and absolute BMI limits to breast reduction surgery is therefore not reasoned or justifiable in the context of gigantomastia. So should we be abandoning the BMI altogether? It is by no means a perfect measure of obesity since athletic or muscular individuals may register as obese despite having low total body fat and excellent fitness.9 Given that the weight of breasts in gigantomastia contribute significantly to the BMI, it would be prudent to consider softening the absolute BMI limits imposed by rationing bodies in these cases. However, we should not lose sight of the usefulness of the BMI, flawed though it is. If we are proposing operating on patients with gigantomastia whose BMIs are greater than 30, we must also be aware of the potential risks of doing so. Obesity is associated with a number of medical conditions such as diabetes, hypertension and increases the risk of general anaesthesia.10 Although most post-operative complications in obese patient groups are limited to minor wound healing problems, these complications become more clinically significant with BMIs over 40.11 Based on our data, it is reasonable to define gigantomastia as excess breast tissue that contributes 3% or more to the patient’s total body weight. This figure is approximately one standard deviation below the mean contribution a resection specimen makes to body weight in our series of 68 women. Applying a definition such as this to breast size means that the short, slim patient with
H. Dafydd et al. extremely large breasts that may not reach 1.5 kg in weight is now more appropriately diagnosed as having gigantomastia. Conversely, the centrally obese patient whose breasts have ‘grown with her’, proportionately, to over 1.5 kg each in weight will no longer be defined as gigantomastia. We have shown that the weight of the resection specimen in gigantomastia contributes significantly to the patient’s BMI. It is proposed that gigantomastia should be defined as excess breast tissue that contributes >3% of the patient’s total body weight. For the purposes of pre-operative assessment in the gigantomastia population, we suggest an adjustment is made to the patient’s BMI based on the estimated excess breast tissue weight. However we make clear that our new definition of gigantomastia is, by necessity, retrospective. The major clinical problem now faced by surgeons is how to accurately estimate the weight of excess breast tissue prospectively. Measuring pre-operative breast weight clinically is usually an inaccurate, subjective estimate. It may be that hospital clinical photography departments can be of assistance here. Photography studios with a 3D camera set up or laser body scanner can rapidly capture a patient’s body map. A computer can extract hundreds of measurements from this data to calculate the breast volume.12 Breast weight is derived by multiplying breast volume with the density of breast tissue. This will vary from person to person depending on the composition of the individual’s breasts, but will be approximately 1 g/cm3 (given that fat is hypodense and blood is hyperdense relative to water). This method could yield a more accurate and reproducible measure of pre-operative breast weight. When coupled with the patient’s body weight, it would allow for a preoperative diagnosis of gigantomastia to be made according to our new definition.
Conflict of interest statement None.
Funding None.
References 1. Lacerna M, Spears J, Mitra A, et al. Avoiding free nipple grafts during reduction mammaplasty in patients with gigantomastia. Ann Plast Surg 2005;55:21e4. 2. Slezak S, Dellon AL. Quantitation of sensibility in gigantomastia and alteration following reduction mammaplasty. Plast Reconstr Surg 1993;91:1265e9. 3. Dancey A, Khan M, Dawson J, et al. Gigantomastia e a classification and review of the literature. J Plast Reconstr Aesthet Surg 2008;61:493e502. 4. NHS Modernisation Agency. Information for Commissioners of Plastic Surgery Services. Referrals and Guidelines in Plastic Surgery. 2005. 5. Dafydd H, Juma A, Meyers P, et al. The contribution of breast and abdominal pannus weight to body mass index: implications for rationing of reduction mammaplasty and abdominoplasty. Ann Plast Surg 2009;62:244e5.
Redefining gigantomastia 6. Collins ED, Kerrigan CL, Kim M, et al. The effectiveness of surgical and nonsurgical interventions in relieving the symptoms of macromastia. Plast Reconstr Surg 2002;109:1556e66. 7. Atterhem H, Holmner S, Janson PE. Reduction mammaplasty: symptoms, complications, and late results. A retrospective study on 242 patients. Scand J Plast Reconstr Surg Hand Surg 1998;32:281e6. 8. Sood R, Mount DL, Coleman JJ, et al. Effects of reduction mammaplasty on pulmonary function and symptoms of macromastia. Plast Reconstr Surg 2003;111:688e94.
163 9. Pounder D, Carson D, Davison M, et al. Evaluation of indices of obesity in men: descriptive study. BMJ 1998;316:1428e9. 10. Adams JP, Murphy PG. Obesity in anaesthesia and intensive care. Br J Anaesth 2000;85:91e108. 11. Wagner DS, Alfonso DR. The influence of obesity and volume of resection on success in reduction mammaplasty: an outcomes study. Plast Reconstr Surg 2005;115:1034e8. 12. Wells JC, Ruto A, Treleaven P. Whole-body three-dimensional photonic scanning: a new technique for obesity research and clinical practice. Int J Obes (Lond) 2008;32:232e8.