Atypical Clinical Presentation of Xeroderma Pigmentosum in a Patient Harboring a Novel Missense Mutation in the XPC Gene: The Importance of Clinical Suspicion

BACKGROUND

Xeroderma pigmentosum (XP) is a genodermatosis caused by abnormal DNA repair. XP complementation group C (XPC) is the most frequent type in Mediterranean countries. We describe a case with a novel mutation in the XPC gene.

CASE

A healthy Caucasian male patient was diagnosed with multiple primary melanomas. Digital follow-up and molecular studies were carried out.

RESULTS

During digital follow-up 8 more additional melanomas were diagnosed. Molecular studies did not identify mutations in CDKN2A, CDK4 or MITF genes. Two heterozygous mutations in the XPC gene were detected: c.2287delC (p.Leu763Cysfs*4) frameshift and c.2212A>G (p.Thr738Ala) missense mutations.

CONCLUSION

The p.Thr738Ala missense mutation has not been previously described. Missense mutations in the XPC gene may allow partial functionality that could explain this unusual late onset XP. Atypical clinical presentation of XPC could be misdiagnosed when genetic aberrations allow partial DNA repair capacity.

Surgical treatment of primary melanoma

The incidence of primary cutaneous malignant melanoma (MM) has been rapidly growing during the last decades with only a small rise in overall mortality. MM accounts for most of the deaths from skin malignancies due to its metastatic potential. However, early detection and wide surgical excision with histologically negative margins are nearly always curative for patients without micrometastatic disease. Although nonsurgical treatments have been increasingly used in recent years, surgery with standardized margins remains the only curative treatment modality for primary cutaneous MM. There are some special locations (e.g., the ear, nose, eyelid, genitalia, hand, or foot) where standardized wide surgery can not be completely achieved either for lack of tissue, ill-defined lesions, or cosmetic and functional reasons. Thus, skin surgeons dealing with these MMs should be well versed in new technologies such as confocal microscopy for the presurgical assessment of ill-defined lesions or the promising electrochemotherapy for nonsurgical tumors. Furthermore, a multidisciplinary melanoma team and a well-trained and experienced surgeon are mandatory to deal with these "out-of-the-guidelines" melanomas.

Multicentric reticulohistiocytosis with elevated cytokine serum levels

Multicentric reticulohistiocytosis (MRH) is an uncommon non-Langerhans cell histiocytosis of unknown etiology. It is a multisystem disorder characterised by a papulonodular skin eruption, mainly in the extensor surfaces, and destructive polyarthritis. Histologically, either cutaneous lesions or the synovium show a dense dermal infiltrate of histiocytes and multinucleated giant cells with an eosinophilic granular material in the cytoplasm. In the immunohistochemical analysis these cells stain positively with monocyte/macrophage markers (CD68 and CD45), as well as with certain cytokines (tumor necrosis factor-α, interleukin 1β and interleukin 6). Moreover, recent reports suggest an osteoclastic nature of the infiltrating cells, as they stain strongly with osteoclast tissue lytic markers including tartrate-resistant acid phosphatase and cathepsin K. We report a case of MRH presenting with clinical features of dermatomyositis. Furthermore, the patient showed elevated cytokine serum levels that lowered after therapy.

Congenital atrichia and hypotrichosis

BACKGROUND

Alopecia present from birth includes a broad differential diagnosis and often represents a diagnostic and therapeutic challenge for the involved physician.

DATA SOURCES

An initial correct diagnosis and classification is essential because structural hair defects may be the expression of a genetic disorder affecting hair growth, part of a congenital syndrome with accompanying hair malformations, or a marker for an underlying metabolic disorder and may impact the mental and physical development of a child. Pathological hair loss rarely occurs in the first year of life; however, it may be a leading symptom of many congenital diseases.

RESULTS

In recent years, the clinical and microscopic features of hereditary hair shaft disorders have been characterized and classified. Furthermore, significant progress has been made in our knowledge of genes that control the normal development and differentiation of hair follicles, and thus the research is to define and classify the hair disorders within a genetic basis.

CONCLUSIONS

In this article we discuss several types of genotrichosis and provide a practical classification based on their clinical features.

Two cases of photocontact allergy to the new sun filter octocrylene

We report two cases of photocontact allergy to a cinnamate sun filter, octocrylene. In the last few years octocrylene has been broadly used in the manufacturing of many cosmetics and UV filters, hence the importance of octocrylene as an emerging cause of contact and photocontact allergy.

[Annular plaques in the skin folds: 4 cases of lichen planus pigmentosus-inversus]

We report 4 patients with relatively asymptomatic, annular brownish plaques arising in the skin creases.The lesions had remained stable for months despite many topical treatments. Histological examination revealed an atrophic epidermis with a dermal lichenoid inflammatory infiltrate showing marked pigmentary incontinence.These clinical and pathological features were consistent with lichen planus pigmentosus-inversus,a rare, recently described variant of lichen planus, with only 10 cases reported to date. It has been suggested that he intensity and speed of onset of the inflammatory response could be modulated by keratinocyte surface markers, which could also determine the typical morphology of the lesions of this disease.