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CASE REPORT
Year : 2022 | Volume
: 26
| Issue : 3 | Page : 35-37
Nonfamilial isolated collagenoma
Farhana T Taj, Dilsha Shareef
Department of Dermatology, Jawaharlal Nehru Medical College, KLE Academy of Higher Education, Belgaum, Karnataka, India
Correspondence Address:
Farhana T Taj
Department of Dermatology, Jawaharlal Nehru Medical College, KLE Academy of Higher Education, Belgaum - 590 010, Karnataka
India
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/jdds.jdds_2_20
Connective tissue nevi (CTN) are hamartomas consisting of the various components of the dermal connective tissue. The predominant element of the extracellular connective tissue within an individual nevus can be collagen, elastic fibers, or glycosaminoglycans. Those predominantly composed of collagen are called collagenomas. CTN can be classified as congenital or acquired, and independent or in association with a systemic disease. Collagenomas are asymptomatic and can be seen over the trunk, arm, thigh, and soles. We present the case of an 18-year-old boy with an isolated collagenoma over the lower back.
Keywords: Collagen nevi, collagenomas, connective tissue nevi, hamartomas
Connective tissue nevi (CTN) are hamartomas that result from increase in or change in extracellular matrix components of the dermis. The three main components can be collagen, elastin, and proteoglycan. The term “connective tissue nevi” was coined by Lewondowsky in 1921.[1] They can present as solitary, multiple or zosteriform, sporadic or inherited, painless pink-colored or flesh-colored nodules or plaques. CTN can be classified as congenital, acquired, isolated, or in association with systemic disease. Syndromic collagenomas can be seen in tuberous sclerosis (TS),[2] multiple endocrine neoplasm Type 1,[3] Buschke–Ollendorff,[4] Proteus,[5] and pseudo-Hurler polydystrophy.[6] We report a case of an isolated nonfamilial collagenoma over the lower back.
Case ReportAn 18-year-old male with no previous personal or family medical history presented with an asymptomatic lesion over the lower back since birth. The patient reported a history of an increase in size over the past month. The patient had no similar lesions and had not attempted any treatment. There was no history of seizures and adenoma sebaceum (angiofibromas) suggestive of TS. On physical examination, there was a well-defined hypopigmented plaque with areas of bluish gray pigmentation of size 4 cm × 1 cm seen over the lower back in the midline [Figure 1]. It was nontender to touch and firm in consistency. Dermoscopy of the lesion revealed brownish globules with faint erythema. Skin biopsy was done from the lesion, which showed dermis with dense collagen bundles arranged haphazardly with few spindle-shaped cells with brown pigment in between [Figure 2]a and [Figure 2]b. Magnetic resonance imaging (MRI) screening of the lesion showed no extension to the spinal cord.
Figure 1: Leaf-shaped hypopigmented plaque with few hyperpigmented spots over the surface
Figure 2: (a) Histopathology image showing normal epidermis with increased thickness of dermis (H and E, ×10). (b) Histopathology image showing increased and haphazardly arranged collagen bundles in the dermis with spindle-shaped cells and pigment incontinenceBased on history, clinical presentation, and histopathological confirmation, a diagnosis of an isolated nonfamilial collagenoma was made The lesion was excised surgically by a pediatric surgeon without any complications.
Discussion1CTN are hamartomas that result from an increase in or change in extracellular matrix components of the dermis. CTN can be classified based on clinical, histopathological, and genetic features [Table 1].[7] Collagenoma or CTN of collagen type are hamartomas which are classified as familial and nonfamilial.
Collagenomas of familial type include familial cutaneous collagenoma and Shagreen patches in TS and nonfamilial type include acquired isolated collagenoma and eruptive collagenoma. Many isolated collagenomas in different patterns have been described. There are reports of isolated collagenomas of scalp mimicking cutis verticis gyrata, multidermatomal zosteriform collagen nevus, and linear collagen nevi.[8],[9],[10],[11],[12]
Nonfamilial, or isolated collagenoma, is due to an increase in Type 1 collagen with a decrease in the enzyme collagenase.[6],[13] Clinically, it presents as a papule, a nodule, and a plaque with hypo or hyperpigmentation. It can present in different morphological patterns such as zosteriform, corymbose, cerebriform, and papulolinear. It is usually asymptomatic and presents as a single plaque on the trunk, arm, and back. Histologically, an isolated collagenoma shows increased and irregularly distributed collagen fibers with a decrease in elastic fibers. Histopathological features are seen in (1) eruptive collagenoma which shows vertically oriented collagen bundles with decreased and fragmented elastic fibers and (2) familial cutaneous collagenomas where a dilution phenomenon is seen; because of collagen buildup, there is decrease in and wider space between elastic fibers. Isolated nonfamilial collagenomas should be differentiated from familial collagenomas, which is associated with cardiac abnormalities and positive family history.[13]
Our patient had isolated asymptomatic hypopigmented plaque without a family history of similar complaints, and histology showed increased and haphazardly arranged collagen fibers. The diagnosis of a nonfamilial isolated collagenoma was made and treated with surgical excision.
In conclusion, sporadic collagenomas have been reported on different body locations with variable clinical morphologies. Thus, thorough history and physical examinations are required to rule out known associations. In addition, imaging such as MRI is needed to assess the extent of the lesion and genetic testing as indicated.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
References
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