Malignant schwannoma associated with xeroderma pigmentosum in a patient belonging to complementation group D

Spontaneous malignant transformation of trigeminal schwannoma: consideration of responsible gene alterations for tumorigenesis-a case report

Malignant peripheral nerve sheath tumors (MPNSTs) arising from the trigeminal nerves are extremely rare (only 45 cases, including the present case, have been published) and have been reported to develop de novo from the peripheral nerve sheath and are not transformed from a schwannoma or neurofibroma. Here, we report a case of MPNSTs of the trigeminal nerve caused by the malignant transformation of a trigeminal schwannoma, with a particular focus on genetic considerations. After undergoing a near-total resection of a histologically typical benign schwannoma, the patient presented with regrowth of the tumor 10 years after the primary excision. Histopathologic and immunochemical examinations confirmed the recurrent tumor to be an MPNST. Comprehensive genomic analyses (FoundationOne panel-based gene assay) showed that only the recurrent MPNST sample, not the initial diagnosis of schwannoma, harbored genetic mutations, including NF1-p.R2637* and TP53-p.Y234H, candidate gene mutations associated with malignant transformation. Moreover, the results of reverse transcription polymerase chain reaction showed that the fusion of SH3PXD2A and HTRA1, which has been reported as one of the responsible genetic aberrations of schwannoma, was detected in the recurrent tumor. Taken together, we could illustrate the accumulation process of gene abnormalities for developing MPNSTs from normal cells via schwannomas.

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.

Malignant peripheral nerve sheath tumors of the trigeminal nerve: a systematic review of 36 cases

OBJECT

Malignant peripheral nerve sheath tumors (MPNSTs) are a rare form of malignancy arising from the Schwann cells of peripheral nerves. MPNSTs of the trigeminal nerve are exceptionally rare, with only a handful of reports in the literature. These tumors are typically very aggressive, resulting in significant patient morbidity and a generally grim prognosis. Most current reports suggest that radical resection with radiation therapy offers the best benefit. In this study, the authors systematically reviewed the world English-language literature on MPNSTs of the trigeminal nerve to analyze the presentations, treatment options, and outcomes for patients with this disease.

METHODS

A literature search for MPNSTs of the trigeminal nerve confined to nonanimal, English-language articles was conducted utilizing the PubMed database, with additional cases chosen from the references of selected articles. Only cases of confirmed MPNSTs of the trigeminal nerve or its peripheral branches, based upon surgical, pathological, or radiological analysis, were included.

RESULTS

From the literature search, 29 articles discussing 35 cases of MPNSTs of the trigeminal nerve were chosen. With the addition of 1 case from their own institution, the authors analyzed 36 cases of trigeminal MPNSTs. The average age of onset was 44.6 years. These tumors were more commonly seen in male patients (77.1%). The gasserian ganglion was involved in 36.1% of the cases. Of the cases in which the nerve distribution was specified (n = 25), the mandibular branch was most commonly involved (72.0%), followed by the maxillary branch (60.0%) and the ophthalmic branch (32.0%), with 44.0% of patients exhibiting involvement of 2 or more branches. Altered facial sensation and facial pain were the 2 most commonly reported symptoms, found in 63.9% and 52.8% of patients, respectively. Mastication difficulty and diplopia were seen in 22.2% of patients, facial weakness was seen in 19.4%, and hearing loss was present in 16.7%. With regard to the primary treatment strategy, 80.6% underwent resection, 16.7% underwent radiation therapy, and 2.9% received chemotherapy alone. Patients treated with complete resection followed by postoperative radiation therapy had the most favorable outcomes, with no patients showing evidence of disease recurrence with a mean follow-up of 34.6 months. Patients treated with incomplete resection followed by postoperative radiation therapy had more favorable outcomes than patients treated with incomplete resection without radiation therapy or radiation therapy alone.

CONCLUSIONS

Trigeminal MPNSTs most commonly present as altered facial sensation or facial pain, although they exhibit a number of other clinical manifestations, including the involvement of other cranial nerves. While a variety of treatment options exist, due to their highly infiltrative nature, aggressive resection followed by radiation therapy appears to offer the greatest chance of recurrence-free survival.

Phenotype-specific adverse effects of XPD mutations on human prenatal development implicate impairment of TFIIH-mediated functions in placenta

Mutations in XPD (ERCC2), XPB (ERCC3), and TTD-A (GTF2H5), genes involved in nucleotide excision repair and transcription, can cause several disorders including trichothiodystrophy (TTD) and xeroderma pigmentosum (XP). In this study, we tested the hypothesis that mutations in the XPD gene affect placental development in a phenotype-specific manner. To test our hypothesis and decipher potential biologic mechanisms, we compared all XPD-associated TTD (n=43) and XP (n=37) cases reported in the literature with respect to frequencies of gestational complications. Our genetic epidemiologic investigations of TTD and XP revealed that the exact genetic abnormality was relevant to the mechanism leading to gestational complications such as preeclampsia. Through structural mapping, we localized the preeclampsia-associated mutations to a C-terminal motif and the helicase surfaces of XPD, most likely affecting XPD's binding to cdk-activating kinase (CAK) and p44 subunits of transcription factor (TF) IIH. Our results suggested a link between TTD- but not XP-associated XPD mutations, placental maldevelopment and risk of pregnancy complications, possibly due to impairment of TFIIH-mediated functions in placenta. Our findings highlight the importance of the fetal genotype in development of gestational complications, such as preeclampsia. Therefore, future studies of genetic associations of preeclampsia and other placental vascular complications may benefit from focusing on genetic variants within the fetal DNA.

A novel mutation in the XPA gene associated with unusually mild clinical features in a patient who developed a spindle cell melanoma

BACKGROUND

Xeroderma pigmentosum (XP) is an autosomal recessive disorder of, in most cases, defective nucleotide excision repair (NER) of ultraviolet radiation (UV)- and chemical-induced DNA damage. The condition is characterized by an increased sensitivity of the skin to UV radiation, with early development of pigmentary changes and premalignant lesions in sun-exposed areas of the skin, signs of photoageing and a greatly increased incidence from a young age of skin tumours including melanoma. Approximately 20% of patients with XP show neurological abnormalities of varying severity due to primary neuronal degeneration. Genetic analysis by somatic cell hybridization has led to the identification in the NER-defective form of XP of seven complementation groups, designated XP-A to XP-G. These complementation groups correspond to different proteins involved in the NER process. XP-A classically includes some of the most severely affected patients.

OBJECTIVES

We describe a 61-year-old Punjabi woman with XP. Remarkably she had only mild cutaneous abnormalities, minimal neurological features and unusual longevity, and developed a malignant spindle cell melanoma. There are few previous reports of spindle cell melanoma associated with XP. To gain insight into the aetiology of these unusual features, we sought to analyse the DNA repair properties of the patient and identify the complementation group and the causative mutation in the defective gene.

METHODS

Unscheduled DNA synthesis and the inhibition of RNA synthesis were measured. The complementation group was assigned by fusing the cells of our patient with XP cells of known complementation groups and determining the ability to carry out unscheduled DNA repair. Molecular analysis of the cDNA was carried out by polymerase chain reaction and DNA sequencing.

RESULTS

Levels of DNA repair were extremely low and complementation analysis assigned the defect to the XP-A group. Sequencing of the XPA gene revealed a novel homozygous mutation of A-->G at the eighth nucleotide of intron 4 causing aberrant splicing and a nonfunctional truncated XP-A protein. However, a small amount of normally spliced mRNA was detected at <5% the level in normal cells.

CONCLUSIONS

The small amount of normally spliced mRNA detected may be sufficient to explain the relatively mild clinical features in our patient.

Xeroderma Pigmentosum: Mondscheinkinder. Xeroderma Pigmentosum: Children of the Moon

Xeroderma pigmentosum is based on a genetic defect in the DNA repair system, which is diagnosed in early childhood. Xeroderma pigmentosum is a rare disorder, which is transmitted in an autosomal recessive manner. Children with xeroderma pigmentosum display hypersensitivity to ultraviolet (UV) radiation. These patients experience serious sunburns with minimal exposure and then develop poikiloderma in the sun-exposed areas. Squamous cell carcinomas, basal cell carcinomas and malignant melanomas all appear during childhood. The majority of patients do not reach adult, but die from metastatic cutaneous malignancies. Genetically, xeroderma pigmentosum is differentiated into 7 complementation groups (XP-A to XP-G) and the xeroderma pigmentosum variants (XP-V). The assignment to the specific complementation group is made by fusing of xeroderma pigmentosum fibroblasts. Xeroderma pigmentosum must be distinguished from other so-called DNA repair deficiency syndromes, including Cockayne syndrome and trichothiodystrophy. A topical DNA repair enzyme appears to be helpful. A recombinant liposomal encapsulated T4 endonuclease V repairs UV-induced cyclobutane-pyrimidine dimers. Direct curative treatment of xeroderma pigmentosum could be achieved with gene therapy in future. Transfection of an intact repair gene which specifically codes for the missing repair protein could open new possibilities in the therapy of xeroderma pigmentosum.

Xeroderma pigmentosum: spinal cord astrocytoma with 9-year survival after radiation and isotretinoin therapy

BACKGROUND

Patients with xeroderma pigmentosum (XP) frequently develop sunlight-induced skin cancer. Infrequently, internal neoplasms may also occur. A 21-year-old patient with XP, who had many skin cancers, developed a rare internal tumour - a grade II diffuse fibrillary spinal cord astrocytoma - during a break in a therapeutic trial of isotretinoin for skin cancer prevention. Treatment of neoplasms in XP patients presents special difficulties because of their defect in DNA repair.

OBJECTIVE

The study objective was to raise awareness of the cancer surveillance process in XP patients and the concerns involved in choice of therapy.

METHODS

Since the spinal cord tumour was inoperable, the patient was treated with x-radiation, continued on isotretinoin treatment and was followed closely for tumour response.

RESULTS

Despite sensitivity to sunlight, the patient had a normal acute response to the x-ray treatment without excessive skin reaction. Serial examinations by magnetic resonance imaging (MRI) starting 8 months after x-ray treatment was initiated, showed a marked gadolinium enhancement followed by regression. This clearing was first seen at 2 years after biopsy and persisted to at least 9 years after treatment.

CONCLUSION

In contrast to the exaggerated sensitivity to UV radiation, XP patients may tolerate therapeutic doses of x-radiation. Isotretinoin treatment may have contributed to the good response of this spinal cord astrocytoma.

Group D xeroderma pigmentosum: a case with a number of nevocellular nevi

A 12-year-old boy was diagnosed as having group D xeroderma pigmentosum based on the results of unscheduled DNA synthesis (UDS) tests and complementation tests. More than 200 moles were distributed all over his body, including the unexposed areas of his torso and scalp. All of eight removed specimens were compatible histologically with nevocellular nevi.