Clinical Characteristics of Connective Tissue Nevi in Tuberous Sclerosis Complex With Special Emphasis on Shagreen Patches

Segmental Collagenoma in Tuberous Sclerosis - Think Beyond the Skin: A Rare Case Report

Collagenomas are connective tissue nevi characterized by an imbalance in the distribution and amount of collagen in the extracellular matrix. Shagreen patch, a collagenoma of tuberous sclerosis, is a classical finding in this genodermatosis (Tuberous Sclerosis). Though the prototypical lesion is a shagreen patch, some individuals manifest only small collagenomas, and these can hinder a diagnosis of tuberous sclerosis and thus mask underlying systemic involvement as was seen in this case we have reported, wherein a 22-year-old male presented with segmental collagenomas over the face and calcified subependymal nodules of the brain on further investigation.

Histological Patterns of Skin Lesions in Tuberous Sclerosis Complex: A Panorama

Tuberous Sclerosis Complex (TSC) is a multisystem genetic disease characterized by cutaneous and extracutaneous hamartomas. The diagnosis is based on the association of major and minor criteria, defined by a consensus conference updated in 2012. The clinical examination of the skin is crucial because seven diagnostic criteria are dermatological: four major (hypomelanotic macules, angiofibroma or fibrous cephalic plaques, ungual fibromas, shagreen patches) and three minor criteria (confetti skin lesions, dental enamel pits, intraoral fibromas). Skin biopsy is commonly performed to assert the diagnosis of TSC when the clinical aspect is atypical. Histopathology of TSC cutaneous lesions have been poorly reported until now. In this article, we review the histologic features described in the literature and share our experience of TSC skin biopsies in our pediatric hospital specialized in genetic disorders. Both hypomelanotic lesions and cutaneous hamartomas (angiofibroma/fibrous cephalic plaques, ungual fibromas, shagreen patches) are discussed, including the recent entity called folliculocystic and collagen hamartoma, with a special emphasis on helpful clues for TSC in such lesions.

Folliculocystic and Collagen Hamartoma: A Subset of Fibrous Cephalic Plaque

Tuberous sclerosis complex is known to cause a variety of cutaneous hamartomas, most commonly hypomelanotic macules, angiofibromas, shagreen patches, and fibrous cephalic plaques. In recent years, a new cutaneous hamartoma that bears physical and histological resemblance to fibrous cephalic plaque has been proposed called folliculocystic and collagen hamartoma. The primary difference between the two diagnoses is the histologic presence of infundibular cysts in the latter. However, some authors have called into question if the two diagnoses are truly distinct. In this case report, we present a patient with tuberous sclerosis complex and fibrous cephalic plaque with infundibular cysts and propose that the presence of cysts should be incorporated into the possible histologic features of fibrous cephalic plaque.

Miliary fibromas in tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a hamartoma syndrome characterized by multiple skin lesions, such as angiofibromas, shagreen patch and miliary fibromas (MiF).

OBJECTIVE

To determine the clinical and histological features of MiF.

METHODS

A retrospective analysis was conducted on 133 adults with TSC. Photography was used to characterize the appearance and location of MiF. Histological features in five skin samples from four individuals were evaluated by a board-certified dermatopathologist.

RESULTS

MiF were observed in 19 of 133 (14%) individuals with TSC. MiF were 1- to 3-mm skin-coloured, sessile papules scattered on the back and rarely buttocks or thighs. Most were scattered in a bilaterally symmetric distribution, but others were asymmetric or associated with a shagreen patch. Histological features of MiF included expansion of the papillary and periadnexal dermis with variable hamartomatous abnormalities involving adjacent epithelial components.

CONCLUSIONS

MiF are distinct from other cutaneous lesions in TSC such as shagreen patches and angiofibromas. Recognition of this entity is important in defining the spectrum of TSC disease and reassuring individuals with TSC that these lesions are benign.

Hereditary Syndromes in Neuroendocrine Tumors

OPINION STATEMENT

Oncologists should be able to discern the salient clinical features of the most common germline mutations that give rise to neuroendocrine tumors. Astute recognition of an index patient affected by a hereditary syndrome can lead to a "tip-of-the-iceberg" phenomenon whereby their entire kindred can then be proactively monitored and managed potentially with substantial reduction of morbidity and mortality. Through careful history-taking, as well as thoughtful assimilation of findings from the physical exam, biochemical laboratories, scans, and pathology reports, the clinician can spot phenotypic clues that distinguish these familial patterns from sporadic cases of tumorigenesis.

Natural history of a fibrous cephalic plaque and sustained eight decade follow-up in an 80 year old with tuberous sclerosis complex type 2

INTRODUCTION

Fibrous cephalic plaques (FCP) are a characteristic manifestation of tuberous sclerosis complex (TSC) and occur in one third of cases. Their natural history and long term course is unknown, as is the outcome of long term follow-up of TSC cases in old age.

PHENOTYPE AND METHODS

We describe an 80 year old with TSC due to a c.2784dupC TSC2 mutation, who was diagnosed in infancy with an FCP and was regularly followed up at the TSC clinic over 8 decades with regular epilepsy treatment and renal monitoring.

RESULTS

Regular clinical photography and clinical records document the plaque at different ages. The FCP naturally resolved at 74 years. Facial angiofibromas also faded with time in the last decade. His epilepsy and renal abnormalities remained under control with careful surveillance and monitoring.

DISCUSSION

Natural aging in the eighth decade causes progressive laxity of collagen and leads to natural resolution of FCPs. This novel finding with a unique 80 year follow up yields valuable insights into the aging changes within FCPs and facial angiofibromas as the pathways linking facial angiofibromas and FCP's through the TGF-β1 pathway are now being elucidated.

CONCLUSION

We present a clinical odyssey showing the natural progression and history of FCPs in TSC and comment on the mechanistic pathways allowing potential interventions in this disfiguring condition. TSC cases can be successfully managed and complications - particularly in the brain and kidney, can be avoided over an entire lifetime. This is encouraging for long term prospects for patients with TSC.

Collagenoma of the Eyelid

The rare case of an eyelid lesion comprised of hamartomatous dermal collagen, known as a collagenoma, is presented. Collagenomas may be sporadically acquired, or inherited as part of numerous autosomal dominant syndromes. In the appropriate clinical context, their diagnosis should prompt a thorough review of systems, systemic examination, and inquiry into family history, to assess for underlying autosomal dominant syndromes. Recognition of collagenomas may thus allow diagnosis of inherited syndromes, allowing patients to obtain appropriate genetic counseling, as well as screening and treatment of associated systemic pathology.

Fibrous cephalic plaques in tuberous sclerosis complex

BACKGROUND

Fibrous cephalic plaques (FCPs) stereotypically develop on the forehead of patients with tuberous sclerosis complex (TSC). They constitute a major feature for TSC diagnosis and may present before other TSC-related cutaneous hamartomas.

OBJECTIVE

To describe the clinical characteristics of FCPs in TSC.

METHODS

A total of 113 patients with TSC were enrolled in an observational cohort study. Retrospective analysis of medical records and skin photography was performed. FCPs were categorized by anatomic location and size.

RESULTS

FCPs were observed in 36% of patients (41 of 113). Of 62 total lesions, 58% were 1 to less than 5 cm, 13% were 5 cm or larger, and 29% were of unknown size mostly because of prior excision. The distribution of lesions was 39% on the forehead, 27% on the face (nonforehead), 3% on the neck, and 31% on the scalp. Fourteen patients had similar lesions less than 1 cm in diameter. Histopathologically, FCPs displayed dermal collagenosis, decreased elastic fibers, and features of angiofibromas or fibrofolliculomas.

LIMITATIONS

Men were under-represented because the cohort was enriched for patients with TSC with lymphangioleiomyomatosis, which occurs in adult women.

CONCLUSION

Two-fifths of FCPs presented on the forehead, with most of the remainder in other locations on the face and scalp. Better recognition of these lesions may lead to earlier diagnosis of TSC.