Proteus syndrome: diagnosis in adulthood

Surgical trauma induces overgrowth in lower limb gigantism: regulation with use of rapamycin is promising

We describe an unclassified overgrowth syndrome characterised by unregulated growth of dermal fibroblasts in the lower limbs of a 35-year-old woman. A PIK3CA gene mutation resulted in lower limb gigantism. Below the waist, she weighed 117 kg with each leg measuring over 100 cm in circumference. Her total adiposity was 50% accounted for by her legs mainly. Liposuction and surgical debulking were performed to reduce the size of the limbs but had exacerbated the overgrowth in her lower limbs. Systemic sepsis from an infected foot ulcer necessitated treatment by an above-knee amputation. Postoperatively, the stump increased in size by 19 kg. A trial of rapamycin to reverse the growth of the stump has shown promise. We discuss the clinical and genetic features of this previously unclassified disorder and the orthopaedic considerations involved.

Potential pitfalls in volume reduction for the treatment of Proteus syndrome

Proteus syndrome is a rare congenital hamartomatous condition that is characterised by a wide range of malformations. Skin and skeletal developmental malformations are common and may manifest as significant physical anomalies. However, few reports have discussed surgical treatment. A 37-year-old woman presented with disproportionate enlargement of the right buttock, which required volume reduction. The overgrown tissue was combined with vascular malformations, which in our patient were extremely thick. The patient experienced massive blood loss during the procedure, due to which a blood transfusion was performed. Pathological findings revealed partial lipohyperplasia with venous malformations. Thus, during operations including incomplete excision, massive bleeding is always a possibility, but is not commonly described in these instances.

Reassessment of the Proteus syndrome literature: application of diagnostic criteria to published cases

The medical care of patients affected by rare disorders depends heavily on experiences garnered from prior cases, including those patients evaluated by the treating physician and those published in the medical literature. The utility of published cases is wholly dependent upon accurate diagnosis of those patients. In our experience, the rate of misdiagnosis in Proteus syndrome (PS) is high. Diagnostic criteria have been published, but these criteria have not been applied consistently and were published after many case reports appeared in the literature. We reviewed 205 cases of individuals reported to have PS in the literature and three of us independently applied the diagnostic criteria to these case reports. Our initial diagnostic congruence was 97.1% (199/205); the discrepancies in six cases were easily resolved. Only 97 (47.3%) of reported cases met the diagnostic criteria for PS; 80 cases (39%) clearly did not meet the criteria; and although 28 cases (13.7%) had features suggestive of PS, there were insufficient clinical data to make a diagnosis. Reported cases that met the PS criteria had a higher incidence of premature death, and other complications (scoliosis, megaspondyly, central nervous system abnormalities, tumors, otolaryngologic complications, pulmonary cystic malformations, dental and ophthalmogic complications) compared to those in the non-Proteus group. The cases that met the criteria were more often male, which has implications for hypotheses regarding the etiology and pathophysiology of PS. We also studied the attributes that led authors to conclude the reported patients had PS when we concluded they did not. We found that two of the diagnostic criteria (disproportionate overgrowth and connective tissue nevi) were often misinterpreted. In PS, the abnormal growth is asymmetric, distorting, relentless, and occurred at a faster rate compared to the rest of the body. Furthermore, PS was associated with irregular and disorganized bone, including hyperostoses, hyperproliferation of osteoid with variable calcification, calcified connective tissue, and elongation of long bones with abnormal thinning. In contrast, non-Proteus cases displayed overgrowth that was asymmetric but grew at a rate similar to the growth found in unaffected areas of the body. Also, the overgrowth in non-Proteus cases was associated with normal or enlarged bones together with ballooning of the overlying soft tissues. Taken together, these data show that (1) PS diagnostic criteria sort individuals with asymmetric overgrowth into distinct groups; (2) individuals with PS were more likely to have serious complications; (3) PS affects more males than females; and 4) the published diagnostic criteria are useful for clinical care and research. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

Lymphangioma circumscriptum: an example of Whimster's hypothesis

Lymphangioma circumscriptum is an uncommon hamartomatous malformation that is not only localized to an area of skin, but also spreads to subcutaneous tissue and muscle (Whimster's hypothesis). We describe a 7-year-old boy with a bluish plaque on the left side of the back and abdomen with clusters of translucent vesicles (frog spawn). Magnetic resonance imaging showed the lymphangioma had spread to muscles and even fat adjacent to the left kidney. We decided against radical surgery as it would have been too aggressive, and limited excision can produce new surface lymphangiomas.

Vascular anomalies in Proteus syndrome

Proteus syndrome (PS) is a complex hamartomatous disorder defined by local overgrowth (macrodactyly or hemihypertrophy), subcutaneous tumours and various bone, cutaneous and/or vascular anomalies (VA). VA are manifold in PS, but their prevalence is unknown so far. In order to further characterize PS, we studied the prevalence of VA in 22 PS patients presenting to our outpatient clinic and reviewed 100 PS patients previously reported between 1983 and 2001. The diagnosis of vascular abnormalities was made on clinical grounds and supported with imaging studies and/or histology in 12 and seven patients out of 22, respectively. Thirty-five VA were identified in 22/22 (100%) of our patients, and more than one type of VA were present in 10 of them. Vascular tumours, portwine stains (PWS), and venous anomalies (varicosities, prominent veins) were equally common. A total of 118 VA were previously reported in 70/100 (70%) PS patients; vascular hamartomas were more prevalent (56/118 = 47.5%), whilst PWS (21.2%) and venous anomalies (22.9%) were slightly less common than in our series, but there is the possibility of under-reporting. Unlike Klippel-Trenaunay syndrome, where VA are mostly confined to the hypertrophic limb, major arteriovenous anomalies are rare, and - similar to the other hamartomas and naevi observed in PS (pigmentary naevi, epidermal naevi, subcutaneous tumours, exostoses) - VA appear to be distributed at random sites on the body. We conclude that VA are among the most common findings in PS. Their varying type and distribution lend further support to the concept of somatic mosaicism.

Principles for the surgical management of patients with Proteus syndrome and patients with overgrowth not meeting Proteus criteria

BACKGROUND

Proteus syndrome is a rare, sporadic disorder consisting of disproportionate overgrowth of multiple tissues, vascular malformations, and connective tissue or epidermal nevi. Patients with Proteus syndrome present with diverse and variable phenotypes because of the syndrome's mosaic pattern of distribution.

METHODS

Eighty patients with Proteus syndrome, satisfying published diagnostic criteria, and 51 patients with overgrowth not meeting Proteus criteria were identified from the literature. Three additional patients, one patient with Proteus syndrome and 2 patients with overgrowth, were treated at the author's institutions and are discussed in detail. All nonorthopedic and noncutaneous surgical interventions were reviewed.

RESULTS

Fourteen genitourinary, 9 gastrointestinal, and 5 otolaryngologic operations were performed on patients with Proteus syndrome. Six genitourinary, 5 gastrointestinal, and 2 otolaryngologic operations were performed on patients with overgrowth not meeting Proteus criteria. Eight patients with Proteus syndrome and 4 patients with overgrowth experienced thoracic manifestations, generally diffuse cystic pulmonary lesions, but only 1 of 12 underwent surgical treatment.

CONCLUSIONS

Patients with visceral manifestations of either Proteus syndrome or overgrowth not meeting Proteus criteria should be treated in a similar manner. Lesions involving the ovaries and testes, because of the high incidence of neoplasm, should be managed aggressively. Gastrointestinal and renal lesions may be managed conservatively with frequent follow-up to minimize abdominal explorations. All patients undergoing surgery should have a thorough preoperative assessment of their airway and pulmonary reserve because of the relatively high frequency of tonsillar hypertrophy and pulmonary cystic involvement.

Proteus syndrome in adulthood

Proteus syndrome is a very rare congenital condition comprising malformations and overgrowth of multiple sorts of tissue. It was described for the first time in 1979 and was termed Proteus syndrome in 1983. The authors describe a 37-year-old patient who was diagnosed initially as having Klippel-Trenaunay-Weber syndrome at the age of 10 years. The patient was operated for a major thoracic lymphatic malformation, which caused functional problems. The operation at older age for this large lymphatic malformation proved to be complex. In addition, the authors address the difficulties in diagnosing Proteus syndrome. Vascular malformations causing functional problems in adulthood require major surgical procedures with a high risk of postoperative complications.

Sudden death caused by pulmonary thromboembolism in Proteus syndrome

We report 3 patients with Proteus syndrome (PS) who died suddenly from pulmonary embolism (PE). The first patient was a male diagnosed with PS at 12 years who had varicose veins, portal vein thrombosis, right iliac vein occlusion and recurrent PE. At age 25 years, he was admitted to the hospital with a severe headache. Despite therapeutic doses of warfarin, investigations for an acute episode of breathlessness showed PE and he was unable to be resuscitated. The second case was a 9-year-old male with PS who collapsed at home and could not be revived. Autopsy revealed that the cause of death was a PE associated with thrombosis of the deep veins (DVT). The third patient was a 17-year-old female undergoing inpatient treatment for sinusitis when she unexpectedly arrested. She could not be revived and a full autopsy revealed a large PE with no identified DVT. We conclude that PE is a serious complication of PS and recommend vigilance concerning the signs and symptoms of thrombosis and PE in individuals with PS, including children. Aggressive evaluation and treatment should be considered urgently in patients with PS and signs or symptoms of DVT.