Xeroderma pigmentosum: clinicopathological review of the multiple oculocutaneous malignancies and complications

Oral mucosa involvement in pediatric patients with xeroderma pigmentosum: a comprehensive review

BACKGROUND

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder presenting with an inability to repair UV-induced DNA damage. This can lead to the development of neoplasms affecting multiple organ systems, with onset often in childhood. Unfortunately, no cure currently exists for XP, and management strategies focus on sun protection and early intervention for malignancies. Although most skin problems in XP patients are UV induced, various oral lesions are also described. However, the literature has not extensively characterized the oral manifestations and their prognostic significance.

METHODS

We conducted a comprehensive review to evaluate the prevalence and nature of oral mucosal lesions in pediatric XP patients.

RESULTS

Our literature search yielded 130 pediatric XP patients with oral involvement and 210 associated tumoral or non-tumoral lesions. Squamous cell carcinoma was the most common type of oral mucosal tumor reported, with other malignancies including basal cell carcinoma, melanoma, angiosarcoma, fibrosarcoma, and trichilemmal carcinoma.

CONCLUSION

Given the potential morbidity and mortality associated with oral mucosal tumors in XP patients, our study aims to raise awareness of these manifestations. Early diagnosis and treatment are crucial for managing these lesions effectively, and routine oral exams should be considered a critical component of dermatological evaluations for XP patients, especially in the pediatric age group.

Whole Exome Sequencing of a Patient with a Milder Phenotype of Xeroderma Pigmentosum Group C

A 17-year-old female Korean patient (XP115KO) was previously diagnosed with Xeroderma pigmentosum group C (XPC) by Direct Sanger sequencing, which revealed a homozygous nonsense mutation in the XPC gene (rs121965088: c.1735C > T, p.Arg579Ter). While rs121965088 is associated with a poor prognosis, our patient presented with a milder phenotype. Hence, we conducted whole-exome sequencing in the patient and her family members to detect coexisting mutations that may have resulted in a milder phenotype of rs121965088 through genetic interaction. Materials and Methods: the whole-exome sequencing analysis of samples obtained from the patient and her family members (father, mother, and brother) was performed. To identify the underlying genetic cause of XPC, the extracted DNA was analyzed using Agilent's SureSelect XT Human All Exon v5. The functional effects of the resultant variants were predicted using the SNPinfo web server, and structural changes in the XPC protein using the 3D protein modeling program SWISS-MODEL. Results: Eight biallelic variants, homozygous in the patient and heterozygous in her parents, were detected. Four were found in the XPC gene: one nonsense variant (rs121965088: c.1735C > T, p.Arg579Ter) and three silent variants (rs2227998: c.2061G > A, p. Arg687Arg; rs2279017: c.2251-6A > C, intron; rs2607775: c.-27G > C, 5'UTR). The remaining four variants were found in non-XP genes, including one frameshift variant [rs72452004 of olfactory receptor family 2 subfamily T member 35 (OR2T35)], three missense variants [rs202089462 of ALF transcription elongation factor 3 (AFF3), rs138027161 of TCR gamma alternate reading frame protein (TARP), and rs3750575 of annexin A7 (ANXA7)]. Conclusions: potential candidates for genetic interactions with rs121965088 were found. The rs2279017 and rs2607775 of XPC involved mutations in the intron region, which affected RNA splicing and protein translation. The genetic variants of AFF3, TARP, and ANXA7 are all frameshift or missense mutations, inevitably disturbing the translation and function of the resultant proteins. Further research on their functions in DNA repair pathways may reveal undiscovered cellular relationships within xeroderma pigmentosum.

Basal Cell Carcinoma in Xeroderma Pigmentosa: Reduced CD1a Expression as a Sensitive Predictor of Recurrence

Xeroderma pigmentosa (XP) is a rare genetic disorder that is characterized by defective DNA repair after ultraviolet induced damage with a great tendency for recurrent cutaneous malignancies including basal cell carcinoma (BCC). BCC is frequently linked to impaired local immune response with a major role played by Langerhans cells (LCs). The current study aims at investigating LCs in BCC specimens of XP and non-XP patients, in a trial to study its possible impact on tumor recurrence. It included 48 retrospective cases of primary facial BCC (18 for XP patients and 30 for non-XP controls). Each group was subdivided, based on the 5 years follow-up data, into recurrent and non-recurrent BCC groups. LCs were assessed immunohistochemically using the sensitive marker; CD1a. Results showed significantly reduced LCs count (intratumoral, peritumoral, and in perilesional epidermis) in XP patients compared with non-XP controls ( P ˂0.001 for all). Intratumoral ( P =0.008), peritumoral ( P =0.005), and perilesional epidermal ( P =0.02) LCs mean values were significantly lower in recurrent versus non-recurrent BCC specimens. Also, within each group (XP and controls), LCs were of significantly lower means in recurrent versus non-recurrent cases ( P ≤0.001 for all). Regarding recurrent BCC cases, peritumoral LCs showed a significant positive correlation with 1ry BCC duration ( P =0.05). Also, intratumoral and peritumoral LCs correlated positively with BCC relapse interval ( P =0.04 for both). Among non-XP controls, periocular tumors had the least LCs count (22.00±3.56), whereas tumors located in the rest of the face had the greatest count (29.00±0.00) ( P =0.02). Sensitivity and specificity of LCs to predict BCC recurrence in XP patients reached 100% in intartumoral area and perilesional epidermis when cutoff points were less than 9.5 and 20.5, respectively. In conclusion; reduced LC count in primary BCC specimens of XP patients and also in normal subjects could help to predict its recurrence. Thus, it might be identified as a risk factor for relapse to apply new strict therapeutic and preventive measures. This presents new avenue for the immunosurveillance against skin cancer relapse. However, being the first study to investigate that link in XP patients recommends further research to confirm.

Recurrent squamous cell carcinoma and a novel mutation in a patient with xeroderma pigmentosum: a case report

BACKGROUND

Xeroderma pigmentosum is an extremely serious genetic disorder defined by sensitivity to sunlight, resulting in sunburn and pigment changes. If patients are not completely protected from ultraviolet radiation, xeroderma pigmentosum is characterized by a greatly increased risk of sunlight-induced cutaneous neoplasms. There is no standard therapy for skin cancer of xeroderma pigmentosum. However, immune checkpoint inhibitors were reported to increase response rates and improve outcomes and life expectancy in patients with various cancers, including squamous cell carcinoma in xeroderma pigmentosum. In this paper, we report on a patient with xeroderma pigmentosum from a consanguineous family with recurrent facial chemotherapy-resistant squamous cell carcinoma lesions treated successfully with an anti-programmed cell death protein 1 monoclonal antibody in both relapses.

CASE PRESENTATION

A 7-year-old Turkish male was referred to our oncology department for recurring squamous cell carcinoma after local excision of the tumor over his nose. The lesion was a rapidly growing lesion, measuring 8 × 4 cm in size. Physical examination revealed that he also had hemorrhagic crusted plaques and nodules over both eyelids and upper lip, with multiple hypo- and hyperpigmented punctate lesions all over his body. After two more cycles of chemotherapy, progressive disease was noted, and a new lesion on the right eyelid caused blurred vision. Anti-programmed cell death protein 1 antibody treatment was planned with concomitant radiotherapy. He received nivolumab every 3 weeks for 4 months, improving his vision. No new lesions or active complaints have been observed in the current situation, and complete remission has been achieved. On the last admission, the patient was clinically diagnosed with xeroderma pigmentosum. Owing to the condition's genetic heterogeneity, whole-exome sequencing was performed with Ion Proton next-generation sequencing platform, and the c.2250 + 1G>A splice site mutation of the XPC gene was detected in the homozygous state.

CONCLUSIONS

The clinical report emphasizes the importance of clinical awareness and crucial early diagnosis of xeroderma pigmentosum and presents a novel causative homozygous c.2250 + 1G>A splice site mutation. Our case proves that next-generation sequencing is an effective method for the rapid diagnosis and determination of xeroderma pigmentosum genetic etiology.

Late Presentation of Xeroderma Pigmentosa With Squamous Cell Carcinoma in Septic Shock: Report of a Rare Case

Xeroderma pigmentosum (XP) is a rare autosomal recessive pathology affecting nucleotide excision repair against ultraviolet radiation. This leads to an increased predisposition to developing ophthalmological, neurological, and cutaneous conditions with an increased cell turnover. This case reports a late presentation of XP presenting with metastatic squamous cell carcinoma (SCC) and septic shock in an eight-year-old Indian male. Emergency management with IV fluid boluses and broad-spectrum antibiotics showed no improvement in vitals. Urgent surgical debridement and tumor debulking failed to improve laboratory values. Postoperative leukocytosis with fever spikes warranted the need to transfer the patient to a super-specialty oncology unit. Such an adverse presentation is commonly seen in XP-related invasive squamous cell carcinoma. Preventive management requires early identification and a multidisciplinary approach involving dermatologists, ophthalmologists, and surgeons. Late presentations revolve around control of the disease process by sharp debridement and chemotherapy with regular surveillance as the lesions tend to reoccur even after excision and chemotherapy.

Second Primary Malignancies following a Diagnosis of Conjunctival Melanoma

BACKGROUND

Although incidence of second primary malignancies (SPMs) has been investigated in patients with cutaneous melanoma and uveal melanoma, limited studies have investigated their occurrence subsequent to conjunctival melanoma (CM). We conducted a retrospective observational study to assess incidence of SPMs in patients with primary CM and to identify associated risk factors.

METHODS

Cases of first primary CM diagnosed from 2000 to 2018 were extracted from the national cancer database Surveillance, Epidemiology, and End Results Program. Standardized incidence ratios (SIR) and excess absolute risk (EAR) of SPMs were calculated compared to a matched cohort from the general population with similar sex, race, age group, and calendar year. EAR was per 10,000 individuals, and a P-value of <0.05 was considered significant.

RESULTS

A total of 471 patients met inclusion criteria, 57 (12.1%) of whom developed second primary malignancies (excluding eye and orbit melanomas) over an average (±SD) follow-up period of 6.8 (±5.0) years. Average age at diagnosis for the overall cohort was 60.2 (±18.6) years. Patients with CM demonstrated a significantly increased risk for overall SPMs relative to the general population, even after excluding eye and orbit melanomas (SIR 1.52; 95% confidence interval [CI], 1.15-1.97; EAR 67.58). Specific sites and malignancy types with increased risk were cutaneous melanoma (SIR 7.95; 95% CI, 4.45-13.12; EAR 45.34), ophthalmic non-melanoma malignancies (SIR 80.92; 95% CI, 2.05-450.84; EAR 3.41), and non-intrahepatic biliary malignancies (SIR 11.72; 95% CI, 1.42-42.32; EAR 6.32). Risk of overall SPMs (excluding eye and orbit melanomas) was significantly increased 5-10 years from diagnosis date.

CONCLUSIONS

Patients with CM had an increased incidence of SPMs compared to the general population. Specifically, these patients developed more cutaneous, ophthalmic non-melanoma, and non-intrahepatic biliary malignancies. These second neoplasms could be due to shared pathophysiology or mutual risk factors. Patients with CM may benefit from surveillance for SPMs, such as annual age-appropriate screenings in the first 10 years after diagnosis.

hSSB2 (NABP1) is required for the recruitment of RPA during the cellular response to DNA UV damage

Maintenance of genomic stability is critical to prevent diseases such as cancer. As such, eukaryotic cells have multiple pathways to efficiently detect, signal and repair DNA damage. One common form of exogenous DNA damage comes from ultraviolet B (UVB) radiation. UVB generates cyclobutane pyrimidine dimers (CPD) that must be rapidly detected and repaired to maintain the genetic code. The nucleotide excision repair (NER) pathway is the main repair system for this type of DNA damage. Here, we determined the role of the human Single-Stranded DNA Binding protein 2, hSSB2, in the response to UVB exposure. We demonstrate that hSSB2 levels increase in vitro and in vivo after UVB irradiation and that hSSB2 rapidly binds to chromatin. Depletion of hSSB2 results in significantly decreased Replication Protein A (RPA32) phosphorylation and impaired RPA32 localisation to the site of UV-induced DNA damage. Delayed recruitment of NER protein Xeroderma Pigmentosum group C (XPC) was also observed, leading to increased cellular sensitivity to UVB. Finally, hSSB2 was shown to have affinity for single-strand DNA containing a single CPD and for duplex DNA with a two-base mismatch mimicking a CPD moiety. Altogether our data demonstrate that hSSB2 is involved in the cellular response to UV exposure.

Clinical Spectrum of Cutaneous Malignancies in Central India: A Retrospective Study

Introduction:

Cutaneous malignancies account for 1%–2% of all the diagnosed cancers in India. Nonmelanoma skin cancers (NMSCs) include basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). Others include melanoma, cutaneous lymphomas, and sarcomas. Exposure to ultraviolet (UV) rays is the most important risk factor associated with skin malignancies, although various other factors are also implicated.

Aims and Objectives:

The aims of this work were to study clinical spectrum with age and sex distribution of cutaneous malignancies and metastasis; to study clinicopathological variants of each type of cutaneous malignancies; and to study the risk factors associated with cutaneous malignancies.

Patients and Methods:

It was a retrospective analysis of clinically and biopsy proven cases of cutaneous malignancies from January 1, 2016 to January 31, 2018. Medical records of patients were assessed with respect to demographic information, clinical examination, dermoscopy, and histopathology. Statistical analysis was done using mean, proportion, and percentage.

Results:

Sixty-six cases with cutaneous malignancies were recruited. There was female preponderance. The most common age group affected was 60–70 years. BCC was the most common malignancy (41%) followed by SCC (30%), malignant melanoma (9%), and cutaneous T-cell lymphoma (1.5%). Head and neck was the most common site involved. The most common clinical type of both BCC and SCC was the nodular type. Acral lentiginous was the most frequent subtype of melanoma reported. The most common predisposing for NMSCs was prolonged sun exposure (46%).

Conclusion:

This study highlights an increasing trend of NMSCs with female preponderance. Head and neck is the most common site involved. Increased risk of NMSCs is seen with increased sun exposure and predisposed genetic conditions. T-cell lymphoma was common than B-cell type. The most common internal malignancy to cause cutaneous metastasis was breast carcinoma.

Ocular Surface Squamous Neoplasia Following Keratoplasty in Xeroderma Pigmentosa: A Series of Seven Cases

Purpose: To describe the clinical features and management of post-keratoplasty ocular surface squamous neoplasia (pk-OSSN) in patients with xeroderma pigmentosum (XP).Methods: Retrospective case series of seven patients with XP.Results: The mean age at diagnosis of pk-OSSN was 22 years (median, 21 years; range, 12 to 37 years). There were four males and three females. Full-thickness keratoplasty (n = 5) and Descemet stripping endothelial keratoplasty (n = 2) were performed for optical (n = 6) and therapeutic indications (n = 1). None of the patients had evidence of OSSN before or at the time of keratoplasty. The mean interval between keratoplasty and pk-OSSN was 44 months (median, 14 months; range, 3 to 109 months). The tumor epicenter was located at the limbus (n = 4), bulbar conjunctiva (n = 1) or cornea (n = 2). The mean dimension of the lesions was 12 mm (median, 11 mm; range, 6 to 18 mm). Treatment details included conjunctival/corneal tumor excision (n = 6), plaque brachytherapy (n = 3; 1 primary, 2 adjuvant) and extended enucleation (n = 1). One patient had tumor recurrence 18 months after OSSN treatment, which was treated with wide excisional biopsy. All patients are alive and free of disease over a mean follow-up period of 37 months (median, 37 months; range, 4 to 65 months).Conclusion: XP patients undergoing keratoplasty can develop OSSN several months to years after keratoplasty and require close follow-up for the same. Wide excisional biopsy with/without plaque radiotherapy is effective in the management of pk-OSSN.

Skin tumors in xeroderma pigmentosum: Evaluation of a large series and a literature review

BACKGROUND

Xeroderma pigmentosum (XP) is a rare genodermatosis with a lifelong propensity to develop malignant skin tumors.

METHODS

In this retrospective study, 24 XP patients were evaluated with regard to frequency and clinicopathological features of benign and malignant skin tumors.

RESULTS

Seventeen patients had at least one malignant skin tumor diagnosed: basal cell carcinoma (BCC) in 13 patients (n = 72), basosquamous carcinoma in three patients (n = 4), squamous cell carcinoma in six patients (n = 13), keratoacanthoma in three patients (n = 15), and melanoma in six patients (n = 18). Most melanomas (n = 15) were in situ lesions. Several benign skin tumors were noted such as tricholemmoma (n = 1), trichoepithelioma (n = 1), trichoblastoma (n = 1), follicular infundibulum tumor (n = 1), keratoacanthoma-like follicular lesion (n = 1), adnexal tumors with folliculosebaceous (n = 1) and tricholemmal differentiation (n = 1), and neurofibroma (n = 1). Benign vascular proliferations including pyogenic granulomas (n = 8), widespread telangiectasias, and senile angioma-like lesions were also observed in 3, 5, and 5 patients, respectively.

CONCLUSIONS

Similar to many reports, BCC was found to be the most common malignant skin tumor. The high prevalence of benign adnexal tumors of follicular differentiation, some of them showing mixed histopathological features and various vascular proliferations in our series raises the question of whether they indicate a formerly undescribed association with XP.

Ocular Features in a Large Cohort of Indians With Xeroderma Pigmentosum

PURPOSE

Xeroderma pigmentosum (XP) is an extreme hypersensitivity to sunlight causing skin freckling and pigmentary changes because of defective DNA repair mechanisms. The purpose of this article is to evaluate the spectrum of ocular and systemic features in XP at a tertiary eye care center in India over 32 years.

METHODS

Data from 418 eyes of 209 patients diagnosed with XP from 1987 to 2018 were reviewed retrospectively for demographics, complaints, ocular features, systemic associations, and their management.

RESULTS

Median age at diagnosis was 2 years (interquartile range, 0.5-5 years). A total of 124 patients (59.3%) were men. There was parental consanguinity in 74.4% cases. Common ocular complaints were photophobia (47.1%), ocular discomfort (45%), defective vision (36.6%), redness (13.4%), tissue growth (12%), white spot (11.2%), and pain (10.5%). At presentation, 43.5% had corneal scars (45.5% were located inferiorly and 70.9% covered visual axis). Corneal vascularization and limbal stem cell deficiency were noted in 37.4%. A total of 56% of patients had at least 1 tumor, and 6.7% had neurological abnormalities. At least 1 ocular surgery was performed in 37.8% of patients. Ophthalmic surgical interventions included tumor excision (23%), keratoplasty (13.4%), and nontumor ocular surface surgery (3.4%).

CONCLUSIONS

XP is a disorder that has high ocular morbidity in Indian patients. The recognition of common signs and symptoms and relative frequency of various ocular complications with time trends will help in managing and reducing the sequelae of this otherwise untreatable and progressive disease.

Corneal endothelial assessment in xeroderma pigmentosum: a case-control study

PURPOSE

To analyze and compare corneal endothelial mosaic in terms of endothelial cell population, morphology and irregularity in patients with xeroderma pigmentosum (XP) with clear corneas with normal age and sex matched subjects using specular microscopy.

METHODS

Nine patients with XP without corneal involvement were evaluated in the study. An age and sex matched group of nine healthy subjects participated as control group. Evaluation of corneal endothelial layer was performed using specular microscopy.

RESULTS

Each study group consisted of five males and four females with total mean age of 28 ± 11.3 years (12-46 years). Endothelial cell density was significantly lower in patients with XP in comparison with controls (P < 0.002). Maximum and minimum cell areas were significantly higher in XP group (P < 0.016 and P < 0.029, respectively). Although central corneal thickness was higher in controls, the difference was not statistically significant (P = 0.106). Furthermore, our study showed that the patients with XP had no difference with controls in terms of coefficient of variation of cell areas.

CONCLUSIONS

This study showed that endothelial cell population can decrease in patients with XP, although other specular microscopic variables such as coefficient of variation and central corneal thickness may remain within normal values.

Conjunctival melanoma in patients with xeroderma pigmentosum: a series of four cases

PURPOSE

To study the demographic features, treatment, histopathology, and outcomes in patients of xeroderma pigmentosum (XP) with conjunctival melanoma.

METHODS

Retrospective case series.

RESULTS

The median age at presentation was 18 years (range 9-30 years). There were three females and one male patient presenting with a median duration of symptoms of 3 months (range 1-60 months). The tumor was located in the bulbar conjunctiva in all 4 patients. All patients had corneal involvement by the tumor. The median tumor basal diameter was 7 mm (range 4-15 mm). Wide tumor excisional biopsy with alcohol keratoepithelectomy, cryotherapy to the free margins, and amniotic membrane grafting was done in three patients. One patient underwent orbital exenteration for extensive tumor. One patient also received adjuvant plaque brachytherapy for microscopic residual tumor. Over a median follow-up of 22 months (range 2-101 months), there were no recurrences, metastasis, or death.

CONCLUSION

Conjunctival melanoma in XP is rare and manifests at a younger age.

Unusual intraoral cancer with unexpected outcome in a patient with xeroderma pigmentosum: An alert for antineoplastic treatment

Xeroderma pigmentosum (XP) is a rare autosomal disorder characterized by extreme sensitivity to ultraviolet radiation. DNA repair mechanisms are impaired, and minimal sun exposure can lead to the development of cutaneous neoplasms in very young patients. Intraoral carcinomas are uncommon and, when present, are located mainly at the tongue tip. We report an unprecedented case of squamous cell carcinoma (SCC) in the floor of mouth of a 23-year-old woman with XP. The patient was referred to the oncologist, and 2 months after surgical resection, she underwent a single session of chemotherapy plus radiotherapy. However, she died 73 hours after undergoing her first chemotherapy session. Considering the unexpected outcome of this case, we also investigated possible exacerbated adverse effects of antineoplastic treatments (especially cisplatin-based chemotherapy) in patients with XP and reviewed the main characteristics of the disease, especially cases with oral manifestations reported in the literature.

Characteristics, management, and outcome of squamous carcinoma of the conjunctiva in a single tertiary cancer center in Jordan

AIM

To evaluate the features and outcome of management of malignant conjunctival squamous tumors in King Hussein Cancer Center (a referral tertiary cancer center in the Middle East).

METHODS

Retrospective case series of 31 eyes for 31 patients with conjunctival squamous neoplasia. Main outcome measures included: age, gender, laterality, tumor location, pathological features, tumor stage, treatment modality, and outcome.

RESULTS

Twenty (65%) patients were males and median age was 58y. Twenty-two (71%) eyes had the tumor in the nasal quadrant. Tumor invasion to nearby structures was seen in 19 (61%) eyes, including the cornea, fornix, eyelid, and orbit in 17 (55%), 1 (3%), 2 (6%), and 3 (10%) eyes, respectively. Eye salvage was achieved by surgical excision with cryotherapy followed by topical chemotherapy in 28 (90%) eyes, and orbital exenteration was necessary in 3 (10%) eyes due to orbital tumor invasion. Tumor recurrence was seen in 7 (23%) eyes, and the significant predictive factors for recurrence were tumor extension onto the nearby structures (P=0.04), tumor invasiveness (P=0.038), and tumor TNM stage (P=0.031). No significant change in visual acuity was seen, and disease related mortality was 6% (2 patients, both had orbital invasion by invasive squamous carcinoma).

CONCLUSION

Conjunctival squamous carcinoma is more common in males. Advanced American Joint Committee on Cancer (AJCC) T-stage, tumor local invasion, more pathologically aggressive tumors, and surgical treatment alone (without adjuvant therapy) are associated with higher risk for recurrence, and orbital invasion is the most important poor prognostic factor for metastasis and death. Treatment strategies should be affected by tumor characteristics at presentation.

Recurrent conjunctival atypical fibroxanthoma in Pigmentosum Xeroderma

CASE REPORT

A 7 year-old boy with Xeroderma Pigmentosum (XP) and who presents a recurrent conjunctival atypical fibroxanthoma after two surgeries. This is the third procedure and the patient is treated with a surgical excision of the tumour and cryotherapy at the surgical bed. Due to the risk of recurrence, topical Mitomycin C 0,02% was added at post-operative care achieving a good clinical outcome.

DISCUSSION

Surgical exeresis with cryotherapy and topical Mitomycin C is an effective treatment for a case of an atypical fibroxanthoma with a high potential for recurrence and invasion. An ophthalmologic follow-up is required for these patients, as well as general paediatric care and support aids.

Understanding photodermatoses associated with defective DNA repair: Syndromes with cancer predisposition

Hereditary photodermatoses are a spectrum of rare photosensitive disorders that are often caused by genetic deficiency or malfunction of various components of the DNA repair pathway. This results clinically in extreme photosensitivity, with many syndromes exhibiting an increased risk of cutaneous malignancies. This review will focus specifically on the syndromes with malignant potential, including xeroderma pigmentosum, Bloom syndrome, and Rothmund-Thomson syndrome. The typical phenotypic findings of each disorder will be examined and contrasted, including noncutaneous identifiers to aid in diagnosis. The management of these patients will also be discussed. At this time, the mainstay of therapy remains strict photoprotection; however, genetic therapies are under investigation.

Childhood cancer predisposition syndromes-A concise review and recommendations by the Cancer Predisposition Working Group of the Society for Pediatric Oncology and Hematology

Heritable predisposition is an important cause of cancer in children and adolescents. Although a large number of cancer predisposition genes and their associated syndromes and malignancies have already been described, it appears likely that there are more pediatric cancer patients in whom heritable cancer predisposition syndromes have yet to be recognized. In a consensus meeting in the beginning of 2016, we convened experts in Human Genetics and Pediatric Hematology/Oncology to review the available data, to categorize the large amount of information, and to develop recommendations regarding when a cancer predisposition syndrome should be suspected in a young oncology patient. This review summarizes the current knowledge of cancer predisposition syndromes in pediatric oncology and provides essential information on clinical situations in which a childhood cancer predisposition syndrome should be suspected.