Isolated SOLAMEN Syndrome.

Sir,

A 31-year-old female born to non-consanguineous marriage presented with a 10-year history of cerebriform hypertrophic swelling afflicting the medial side of her left hand. The swelling was associated with episodic localized pain on exertion. There were no reported similar lesions in detailed family history. On clinical examination, her left ring and middle fingers were proportionately longer and thicker compared to the contralateral ones on the right hand [Figure 1a and b]. There was a visible hypertrophic swelling of the palmar surface of the left ring finger that was neither pulsatile nor tender. There were no overlying skin color changes on the left hand and forearm or associated pigmentary macules on the rest of her skin surface. Her radial and ulnar pulsation were normal, with normal systemic blood pressure. The bilateral axillary lymph node examination showed no abnormalities. The whole body was screened but no other abnormality or hamartoma was found. There was no personal or family history of seizures or any neurological disorders. We considered a differential diagnosis of Proteus syndrome, Macrodystrophia lipomatosa, SOLAMEN (Segmental overgrowth, lipomatosis, arteriovenous malformation, and epidermal nevus) syndrome, Fibrolipomatous hamartoma, Plexiform neurofibroma, and Klippel–Trenaunay–Weber syndrome [Table 1]. The Color Doppler ultrasound of the left upper limb revealed a soft-tissue swelling (38.0 mm × 9.7 mm) in the left ring finger and left the metacarpal bone area with increased vascularity in the lesion consistent with a hemangiomatous malformation in the left hand. The magnetic resonance imaging (MRI) of the left hand revealed a minimal soft-tissue thickening with T2 and STIR hyperintensity surrounding the muscles and tendons of the left ring finger without bone or joint involvement [Figure 2 and Supplemental Figures 1, 2]. A punch biopsy was obtained from the soft-tissue overgrowth that showed a collection of disorganized mature adipocytes within the stroma, consistent with lipomatosis [Supplemental Figure 3]. Due to a lack of facilities, the genetic study for the patient and her family members was not available. Based on the clinicopathological correlation and radiological assessment, the possibility of an isolated localized SOLAMEN syndrome is highly likely.

Figure 1

(a and b) Showing cerebriform hypertrophy of the medial side of the left hand

Table 1

Differentials of segmental hypertrophy of the limb

Differential diagnosis	Clinical features	Pathological findings
Proteus syndrome	Hemihypertrophy with asymmetrical partial gigantism, skull abnormalities, pigmented naevi, lung cysts, dermatologic changes like palmar and plantar cerebroid thickening and intra-abdominal lipomas. Cerebriform connective nevus has deep gyri	Asymmetric overgrowth of soft-tissue, bone, adipose tissue, and vascular malformations
SOLAMEN syndrome	Segmental overgrowth, lipomatosis, arteriovenous malformation and epidermal nevus. Segmental proportionate overgrowth of soft-tissue without deep gyri or sulci. Multiple lipomatosis, macrocephaly, breast and thyroid hamartomas	Findings suggestive of lipomatosis or angiolipoma. No involvement of bony structure
Macrodystrophia lipomatosa	Affects only the plantar and median nerve with localized disproportionate gigantism affecting the phalanges, metacarpals, and soft-tissue	Increased adipose tissue with scattered fibrous tissue that may involve periosteum, nerve sheath, and muscle
Fibrolipomatous hamartoma	Mostly affects the median nerve, digital overgrowth, paresthesia, motor deficit, and pain along the affected nerve	Perineural and endoneural fibrosis, infiltration of interfascicular connective tissue by mature fat cells
Neurofibromatosis	Positive family history in many cases, bilateral involvement, café au lait macules, Lisch nodules, freckling in axilla	Nonencapsulated bundles of spindle cells with wavy nuclei, no adipose tissue involvement
Klippel-Trenaunay- Weber disease	Port-wine stain, varicose veins, osseous, and soft-tissue hypertrophy, venous malformation	Irregular venous-type channels with flattened endothelial lining and surrounded by smooth muscle

Figure 2

Showing MRI of the left hand which revealed a minimal soft-tissue thickening with T2 and STIR hyperintensity surrounding the muscles and tendons of the left ring finger without any evident bone or joint involvement

The SOLAMEN syndrome is considered a segmental exacerbation of the Cowden disease.[1] It is a Proteus-like disease caused by a mosaic PTEN (Phosphatase and Tensin homolog), wild-type allelic loss which distinguishes it from the Proteus syndrome [Table 2].[12] The tumor-suppressor gene, PTEN, shows somatic mutations in a wide variety of sporadic neoplasia.[3] The SOLAMEN syndrome is characterized by progressive development of numerous hypertrophic, hamartomatous, and neoplastic lesions involving the skin, mucous membranes, gastrointestinal tract, thyroid, breast, brain, and genito-urinary system. Lipomas, angiomas, and macrocephaly are frequently associated. The SOLAMEN syndrome represents a segmental exacerbation of some autosomal-dominant disorders, as hypothesized by Rudolph Happle. Further, a bi-allelic inactivation of PTEN can lead to developmental anomalies rather than malignant transformation.[2] To our knowledge, only two cases of the SOLAMEN syndrome have been reported in the literature for patients with a positive family history of the Cowden disease.[4] Our case was unique in terms of the localized isolated patterns without Cowden disease. Clinical suspicion is more important where there is a lack of genetic study. The treatment is multidisciplinary involving plastic, ortho, and Laser therapy to correct the anomaly.

Table 2

Difference between SOLAMEN syndrome and Proteus syndrome

SOLAMEN Syndrome	PROTEUS Syndrome
Thickened palm or sole only has wrinkling without deep gyri	Cerebriform connective tissue nevi has deep grooves and gyration
Proportionate segmental overgrowth with soft-tissue hypertrophy	Asymmetric, disproportionate overgrowth with tissue hypertrophy and hyperostosis
Multiple lipomatosis with angio-lipoma or fibrolipoma or invasive lipomas	Lipomas are associated with some areas of regional absence of fatty tissue
Mucocutaneous lesions, macrocephaly, breast or thyroid hamartomas are present as in the Cowden disease	Cowden disease manifestations not marked

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Showing MRI left hand revealed minimal soft-tissue thickening with T2 and STIR hyperintensity surrounding the muscles and tendons left ring finger without any evident bone or joint involvement

Showing MRI left hand revealed minimal soft-tissue thickening with T2 and STIR hyperintensity surrounding the muscles and tendons left ring finger without any evident bone or joint involvement

H and E Stain (40X) showing a collection of disorganized mature adipocytes within the stroma