Acral papular neuromatosis: an early manifestation of Cowden syndrome

The Skin in Cowden Syndrome

Cowden syndrome (CS) is an autosomal dominant condition caused by mutations in the phosphatase and tensin homolog (PTEN) gene, and is characterized by multiple hamartomas and a predisposition to malignant tumors. Characteristic skin lesions include trichilemmomas, acral keratosis, mucocutaneous neuromas, oral papillomas, and penile macules, and are often the first clues to the underlying diagnosis. Here, we discuss the mucocutaneous manifestations of CS, differential diagnoses of genetic causes of each cutaneous finding, genetic analyses for patients with skin manifestations, management of patients with CS, and potential new targeted therapies for CS.

Congenital infiltrating lipomatosis of the face with lingual mucosal neuromas associated with a PIK3CA mutation

We report the case of a 5-year-old girl with congenital right-sided facial hemihypertrophy and right hemi-macroglossia with lingual mucosal neuromas. The segmental presentation of findings suggested the diagnosis of congenital infiltrating lipomatosis of the face (CILF), which belongs within the PIK3CA-related overgrowth spectrum (PROS). This was confirmed by genetic analysis showing a mosaic mutation in PIK3CA H1047R. CILF/PROS should be considered in the differential diagnosis of mucosal neuromas.

PTEN Hamartoma tumor syndrome in childhood: A review of the clinical literature

PTEN hamartoma tumor syndrome (PHTS) is a highly variable autosomal dominant condition associated with intellectual disability, overgrowth, and tumor predisposition phenotypes, which often overlap. PHTS incorporates a number of historical clinical presentations including Bannayan-Riley-Ruvalcaba syndrome, Cowden syndrome, and a macrocephaly-autism/developmental delay syndrome. Many reviews in the literature focus on PHTS as an adult hamartoma and malignancy predisposition condition. Here, we review the current literature with a focus on pediatric presentations. The review starts with a summary of the main conditions encompassed within PHTS. We then discuss PHTS diagnostic criteria, and clinical features. We briefly address rarer PTEN associations, and the possible role of mTOR inhibitors in treatment. We acknowledge the limited understanding of the natural history of childhood-onset PHTS as a cancer predisposition syndrome and present a summary of important management considerations.

PTEN Hamartoma Tumor Syndrome: A Clinical Overview

The phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is a grouping of related genetic disorders that has been linked to germline mutations in the PTEN gene. These disorders include Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome, adult Lhermitte–Duclos disease, and autism spectrum disorders associated with macrocephaly. The majority of the clinical information available on PHTS, however, is related to individuals diagnosed with CS. There is still much to be learned about this disorder, since diagnostic criteria for CS were only established in 1996, before the identification of the PTEN gene, and were based primarily on features seen in cases reported in the existing literature. More recently, however, data from several large series of patients have shown that a number of the clinical features associated with PTEN mutations are either more or less common than previously reported. In addition, we now know that only about 30–35% of patients meeting clinical diagnostic criteria for Cowden syndrome actually have a detectable PTEN mutation. Thus, our understanding of PTEN-related diseases and their management has evolved significantly over time. The United States National Comprehensive Cancer Network (NCCN) has produced and regularly updates practice guidelines which include clinical diagnostic criteria as well as guidelines for PTEN testing and management of patients with mutations. This review will summarize the overall literature on PHTS as well as recent findings which are broadening our understanding of this set of disorders.

Dermal Hyperneury and Multiple Sclerotic Fibromas in Multiple Endocrine Neoplasia Type 2A Syndrome

Importance

Multiple endocrine neoplasia type 2 (MEN 2) syndrome is an autosomal dominant, hereditary cancer disorder caused by germline mutations in the RET (formerly MEN2A, MEN2B) proto-oncogene located on chromosomal band 10q11.21. Two distinct clinical forms have been described as the following phenotypes: multiple endocrine neoplasia type 2A (MEN 2A) and multiple endocrine neoplasia type 2B (MEN 2B) syndromes. The common and necessary nexus that defines these 2 phenotypes is the presence of medullary thyroid carcinoma (MTC). The familial MTC type of MEN 2 syndrome was included within the spectrum of MEN 2A syndrome. Cutaneous manifestations of MEN 2A syndrome include macular amyloidosis, whereas MEN 2B syndrome is traditionally linked to multiple mucosal neuromas.

Objectives

To describe a family with cutaneous manifestations not previously described in patients with MEN 2A syndrome and to discuss the association of this disorder with Cowden syndrome.

Design, Setting, and Participants

Clinicopathologic correlation of cutaneous lesions and genetic studies in 11 members of a family with familial MTC.

Interventions

Cutaneous lesions were histopathologically and immunohistochemically studied. Genetic screening for a germline mutation at the RET gene was performed in 11 family members.

Main Outcomes and Measures

Identification of cutaneous lesions not previously described in patients with MEN 2A syndrome.

Results

This family of 11 individuals with familial MTC type of MEN 2A syndrome demonstrated the moderate risk RET p.Val804Met (protein valine at residue 804 replaced by methionine) genetic mutation, with 2 of the relatives presenting with dermal hyperneury, cutaneous lesions classically described in MEN 2B syndrome, and 1 relative also showing multiple sclerotic fibromas, a cutaneous manifestation of PTEN (phosphatase and tensin homologue) hamartoma-tumor syndrome.

Conclusions and Relevance

Dermal hyperneury and multiple sclerotic fibromas should be added to the list of cutaneous manifestations of patients with the familial MTC type of MEN 2A syndrome.

Genodermatosis Affecting the Skin and Mucosa of the Head and Neck: Clinicopathologic, Genetic, and Molecular Aspect--PTEN-Hamartoma Tumor Syndrome/Cowden Syndrome

PTEN hamartoma tumor syndrome refers to a spectrum of disorders caused by mutations in the phosphatase and tensin homolog (PTEN) gene. Cowden syndrome, the principal PTEN-related disorder is characterized by multiple neoplasms and hamartomas, mucosal papillomatosis, and skin lesions, trichilemmomas. Trichilemmomas and mucocutaneous papillomatous papules are one of the first signs of the disease. Early recognition of these skin lesions may help on diagnosing an underlying malignancy and early cancer screening.

Cutaneous manifestation of gastrointestinal disease

The gastrointestinal (GI) and cutaneous systems are closely linked in origin. Skin manifestations are frequently seen as a part of different GI syndromes. Gastroenterologists play an important role in recognizing the symptoms, patient workup and arriving at appropriate diagnoses, often in consultation with dermatologists. This review discusses the diseases with both cutaneous and intestinal involvement. Hereditary polyposis GI cancers, hereditary nonpolyposis colorectal cancers (CRCs), hamartomatous disorders, and inflammatory bowel disease (IBD) are reviewed with emphasis on the genetic basis, diagnostic, histologic findings, screening modalities, and therapeutic options.

PTEN gene: a model for genetic diseases in dermatology

PTEN gene is considered one of the most mutated tumor suppressor genes in human cancer, and it's likely to become the first one in the near future. Since 1997, its involvement in tumor suppression has smoothly increased, up to the current importance. Germline mutations of PTEN cause the PTEN hamartoma tumor syndrome (PHTS), which include the past-called Cowden, Bannayan-Riley-Ruvalcaba, Proteus, Proteus-like, and Lhermitte-Duclos syndromes. Somatic mutations of PTEN have been observed in glioblastoma, prostate cancer, and brest cancer cell lines, quoting only the first tissues where the involvement has been proven. The negative regulation of cell interactions with the extracellular matrix could be the way PTEN phosphatase acts as a tumor suppressor. PTEN gene plays an essential role in human development. A recent model sees PTEN function as a stepwise gradation, which can be impaired not only by heterozygous mutations and homozygous losses, but also by other molecular mechanisms, such as transcriptional regression, epigenetic silencing, regulation by microRNAs, posttranslational modification, and aberrant localization. The involvement of PTEN function in melanoma and multistage skin carcinogenesis, with its implication in cancer treatment, and the role of front office in diagnosing PHTS are the main reasons why the dermatologist should know about PTEN.