Keywords
Proteus - lipomatosis - intra-abdominal
Case Report
A 5-year-old male patient was admitted with right abdominal swelling. He had underwent
an operation for an enormous lipoma, approximately 20 cm in diameter, on his back
in our clinic when he was 1.5 years old, and plastic surgery was performed following
amputation for macrodactyly of his right first and second toes when he was 4 years
old. During this time, he had no abdominal scanning. On physical examination, he had
an abdominal mass almost 30 cm in diameter, a right lower extremity overgrowth, two
amputated right foot fingers, and an incision scar on his back. Abdominal magnetic
resonance imaging revealed a giant hypodense lesion, stretching from the inferior
of the liver to the inguinal region covering the right kidney and the right ureter.
The density of the masses were approximately −100 HU, in accordance with lipid density,
both lining intra- and extraperitoneally ([Fig. 1]). The mass had begun to impair his motor development and mobility. At laparotomy,
a giant mass was found, surrounding all the abdominal organs, including the liver,
kidney, ureter, mesocolon, colon, omentum, and intestines on the right side and extending
to the inguinal canal. The lipomas were meticulously dissected from the surrounding
organs and completely excised ([Fig. 2]). The postoperative period was uneventful. Liposuction was planned to remove the
remainder of the adipose tissue in the right lower extremity. Pathological examination
revealed a lipoma.
Fig. 1 Abdominal magnetic resonance imaging revealed a giant hypodense lesion, stretching
from the inferior of the liver to the inguinal region covering the right kidney and
the right ureter.
Fig. 2 Abdominal lipomatosis was meticulously dissected from the surrounding organs and
completely excised.
Discussion
Proteus syndrome (PS) is an extremely rare sporadic disorder that manifests as an
asymmetric, disproportionate overgrowth of any connective tissues, such as bone, fat,
or epidermal nevi, in a mosaic or patchy pattern. This hamartoneoplastic syndrome
was first described by Cohen and Hayden.[1] Its prevalence is approximately 1 per 1,000,000 live births, and intra-abdominal
expansion has been reported in no more than 20 cases in the literature.[2]
Diagnosing PS is a challenge due to its different presentations and the overgrowth
of different tissues and localizations. In 1999, Biesecker et al developed diagnostic
criteria ([Table 1]) and evaluation guidelines to clarify the diagnostic confusion.[3] The coexistence of the syndrome with other manifestations such as scoliosis, central
nervous system anomalies, and thoracic deformity anomalies has also been described.[4]
Table 1
Proteus criteria
|
Mandatory general criteria
|
|
Mosaic distribution of lesions
Progressive course
Sporadic occurrence
|
|
Specific criteria (1 from A, 2 from B, or 3 from C)
|
|
A.
|
-
Connective tissue nevus
|
|
B.
|
-
Epidermal nevus
-
Disproportionate overgrowth (one or more)
-
Specific tumors before the end of the second decade (either one)
|
|
C.
|
-
Dysregulated adipose tissue (either one)
-
Lipomas
-
Regional absence of fat
-
Vascular malformations
-
Facial phenotype
|
Source: Adapted from Biesecker et al.[3]
Some overgrowth syndromes including PS, Klippel–Trenaunay syndrome, and hemi-hyperplasia-multiple
lipomatosis syndrome have been delineated. Sapp et al defined a new overgrowth syndrome
resembling PS named CLOVE (congenital lipomatous overgrowth, vascular malformation,
epidermal nevus) syndrome.[5] Our case differed from the CLOVE syndrome because there was no vascular malformation,
epidermal nevi growth, or the presence of skeletal overgrowth.
Biesecker et al have been working in the field of overgrowth and presented recent
diagnostic criteria for PS.[6]
[7]
[8] Our case showed all the major diagnostic criteria of the syndrome, that is, mosaic
distribution, a progressive course, and sporadic occurrence. As in our case, lipomas
in PS are composed principally of mature adipocytes, and the adipose tissue shows
dysregulation.[3]
Our patient also had macrodystrophia lipomatosa, which is characterized by the enlargement
of one or more fingers or toes with predominantly fibroadipose tissue. Macrodystrophia
lipomatosa can be part of an overgrowth syndrome such as PS,[8] as in our patient, or CLOVES syndrome,[5] or it can be found as an isolated abnormality in an otherwise normal patient.[9]
[10]
The syndrome is so rare that there are few case reports in the literature. In 2002,
Lublin et al[11] described three patients with PS and conducted a review of the literature regarding
abdominal, otolaryngological, and thoracic manifestations and surgical complications.
Their three patients with intra-abdominal occurrence of the syndrome were treated
conservatively. One of the patients, a male, required an emergent exploration for
an acute abdomen secondary to a twisted necrotic portion of the right iliac. One of
the other two patients with retroperitoneal PS was treated conservatively, and the
other underwent an operation for extension to the inguinal canal, as in our case.[11] The surgical approach to PS with intra-abdominal and retroperitoneal extension is
primarily conservative, with surgery reserved for cases that are invasive in nature
or where the pathology causes compressions or complications.
Any organ or tissue can be affected in PS; therefore, the secondary complications
are highly variable. It is associated with a range of tumors, pulmonary complications,
progressive skeletal deformities, invasive recurrent lipomas, and a striking predisposition
to deep vein thrombosis and pulmonary embolism.[12] For the last 1 year, our patient is under careful follow-up to detect local relapse
with abdominal ultrasongraphy in every 6 months.
By presenting a case with PS, we aim to draw attention to the diagnosis, the treatment
modalities, and the place of surgical intervention in this rare disorder. Despite
their histological appearance, intra-abdominal lipomas increase the potential for
invasiveness in patients with PS. Such patients must have a conservative follow-up,
with periodic radiological imaging. Surgical intervention is indicated when the overgrowth
causes physical compression of the surrounding organs, as in our case.
