The role of STK 11 gene testing in individuals with oral pigmentation

Facial Features of Hereditary Cancer Predisposition

In the age of telehealth medicine, an individual's facial features may provide the only physical clues signaling the presence of a heritable cancer predisposition syndrome. These syndromes include APC-associated polyposis, Birt-Hogg-Dubé syndrome, CYLD cutaneous syndrome, hereditary leiomyomatosis and renal cell cancer, multiple endocrine neoplasia, neurofibromatosis type 1, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, and tuberous sclerosis complex 1 and 2, among others. Correctly identifying characteristic features is important for genetic and nongenetic specialists as early detection can enable prompt intervention, improving patient outcomes. Advancements in the availability of genetic testing allow patients and their relatives to have more information about their genetic risk profile than before. These changes in clinical pathways, combined with improvements in screening and risk-reducing treatment, highlight the need to outline the cutaneous and morphologic features of high-risk cancer syndromes for clinicians. In this review, we describe the important facial features of hereditary cancer predisposition, with emphasis on diagnosis, cutaneous and extracutaneous manifestations, and screening.

Peutz-Jeghers syndrome: Skin manifestations and endocrine anomalies (Review)

Peutz-Jeghers syndrome (PJS), a rare autosomal dominant serine/threonine kinase 11 (STK11)/ liver kinase B1 (LKB1) gene-related genodermatosis, is characterized by oral hyperpigmentation (OHP); multiple gastro-intestinal mucosal benign hamartomatous polyps causing local bleeding, occlusion, intussusception, post-resection small bowel syndrome, associated increased risk of small intestinal cancer (incidence during the third decade); and 76% cumulative higher risk than the global population of developing non-gastrointestinal tumors (female predominance) including ovarian/testicular neoplasia, pancreatic and gynecologic (breast, uterus, ovarian) cancers. Suggestive PJS-associated OHP requires STK11 genetic testing. Abdominal pain in an OHP patient may be related to PJS-associated polyps. Other features include focal depigmentation followed by hyperpigmentation, and xeroderma pigmentosum-like lesions. The severity of the dermatological findings is correlated with gastrointestinal polyps. The STK11 gene is linked to reserve of primordial follicles, polycystic ovary syndrome, female fertility, and spermatogenesis. PJS is associated with 2 types of ovarian sex-cord stroma tumors (SCSTs): annular tubules (SCTATs) and pure Sertoli cell tumors. SCSTs accounts for 8% of ovarian cancer and SCTATs represents 2% of SCST, which may be associated with the overproduction of progesterone. PJS-SCTAT vs. non-PJS-SCTAT reveals bilateral/multifocal, small tumors with a benign behavior vs. a unique ovarian, large tumor with increased malignant/metastasis risk. Male precocious puberty is due to large cell calcifying Sertoli cell tumors (LCCSCTs). Notably, 30-40% of LCCSCTs are caused by PJS or Carney complex. PJS-LCCSCT is not aggressive, but it may be bilateral/multifocal, with the ultrasound hallmark being micro-calcifications. Testicular, intra-tubular large cell hyalinizing Sertoli cell tumor is the second testicle neoplasia in PJS. The skin and mucosal lesions are useful markers of PJS, assisting with the early identification of hamartomatouspolyps and initiation of serial surveillance of ovarian, or testicular neoplasia.

The Management of Peutz-Jeghers Syndrome: European Hereditary Tumour Group (EHTG) Guideline

The scientific data to guide the management of Peutz–Jeghers syndrome (PJS) are sparse. The available evidence has been reviewed and discussed by diverse medical specialists in the field of PJS to update the previous guideline from 2010 and formulate a revised practical guideline for colleagues managing PJS patients. Methods: Literature searches were performed using MEDLINE, Embase, and Cochrane. Evidence levels and recommendation strengths were assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). A Delphi process was followed, with consensus being reached when ≥80% of the voting guideline committee members agreed. Recommendations and statements: The only recent guidelines available were for gastrointestinal and pancreatic management. These were reviewed and endorsed after confirming that no more recent relevant papers had been published. Literature searches were performed for additional questions and yielded a variable number of relevant papers depending on the subject addressed. Additional recommendations and statements were formulated. Conclusions: A decade on, the evidence base for recommendations remains poor, and collaborative studies are required to provide better data about this rare condition. Within these restrictions, multisystem, clinical management recommendations for PJS have been formulated.

Novel germline STK11 variants and breast cancer phenotype identified in an Indian cohort of Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) caused by germline STK11 variants is a rare autosomal dominant cancer predisposition syndrome characterized by multiple gastrointestinal (GI) hamartomatous polyps, mucocutaneous pigmentation and a high inherited risk of developing GI, breast and other cancers. Despite GI and breast being the two most common PJS-associated cancer sites, the immunohistochemical (IHC) and molecular features of these tumors in carriers of STK11 variant is not known. Detailed phenotyping including tumor IHC and its correlation with comprehensive STK11 genotyping by full gene sequencing followed by large genomic rearrangement analysis was performed in an Indian PJS cohort. A total of 4 distinct STK11 pathogenic or likely pathogenic variants were identified in 10 PJS cases from 7 of the 19 families tested-in 4/5 classical PJS families and 3/14 suspected PJS families. The pathogenic STK11 variant identified was novel in 3/7 families. In addition, four distinct, likely benign variants identified in seven families were also novel. All of the four breast cancer cases in families with STK11 pathogenic variant were estrogen receptor (ER)-positive and Her2-negative. Several novel STK11 variants identified in this Indian PJS cohort highlight the need to study PJS in different populations across the world. This is the first report showing ER positivity in breast cancer in carriers of STK11 variants and needs confirmation in a larger pooled cohort of PJS associated breast cancers. This could help establish the role of chemoprevention or prophylactic oophorectomy in female carriers of STK11 pathogenic variants.

Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier-Hunziker syndrome

Labial and oral melanotic macules are commonly encountered in a broad range of conditions ranging from physiologic pigmentation to a sign of an underlying life-threatening disease. Although Laugier-Hunziker syndrome (LHS) shares some features of labial and oral pigmentation with a variety of conditions, it is a benign and acquired condition, frequently associated with longitudinal melanonychia. Herein, the demographic, clinical, dermoscopic, and pathological aspects of LHS were reviewed comprehensively. The important differential diagnoses of mucocutaneous and nail pigmentation are provided. An accurate diagnosis is crucial to design a reasonable medical strategy, including management options, malignant transformation surveillance, and psychological support. It is important that clinicians conduct long-term follow-up and surveillance due to the potential risks of malignant transformation and local severe complications in some conditions.

Laugier-Hunziker Syndrome Presenting with Metachronous Melanoacanthomas

Laugier-Hunziker syndrome (LHS, also termed idiopathic lenticular mucocutaneous hyperpigmentation) is an unusual condition characterized by progressive pigmentation of the mucous membranes. LHS displays a benign course and is not associated with malignancy. Here we present a case of LHS with a 7-year follow-up. We document metachronous oral melanoacanthomas in this individual. In addition, we found that the oral melanotic macules in this patient waxed and waned in a cyclical manner. To our knowledge, this is the first report of these findings in the context of LHS. Finally, we provide an overview of other conditions that can present with mucosal hyperpigmentation. It is critical to distinguish LHS from other conditions characterized by mucosal pigmentation in order to facilitate optimal patient care.

Laugier-Hunziker syndrome: A case report

Laugier-Hunziker syndrome (LHS) is a rare, benign, acquired pigmentary condition mainly affecting lips, oral mucosa and acral area, frequently associated with longitudinal melanonychia. Herein, we reported a 45-year-old female case with LHS. The clinical, dermoscopic, histopathologic features of LHS were reviewed and the important differential diagnosis was discussed.