A Case of Punctate Leukoderma after 1,064 nm Q-Switched Nd:YAG Laser

Punctate leukoderma is characterized of the destruction of melanocytes after chemical of physical damage. In addition, the term is broadly used to describe hypopigmented lesions induced in vitiligo patients after psolaren administration with ultraviolet A and in psoriasis patients with repetitive ultraviolet B phototherapy. The Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser in treating melasma is frequently reported to be associated with the cause. A 44-year-old woman presented to the department with numerous confetti-like hypopigmented macules on both cheeks for over a year. Weekly treatment of 1,064 nm Qswitched Nd:YAG laser (2.0–3.4 J, 8 mm spot-size) therapy at a non-dermatologic clinic had induced both hyperpigmentation and hypopigmentation lesions. Biopsy performed at both hyperpigmented and hypopigmented lesions revealed variable melanin pigmentation with segmental loss and infiltration of pigment incontinence. The patient was diagnosed with punctate leukoderma and was directed for narrow-band ultraviolet B phototherapy. Herein, we report a case of punctate leukoderma after inadvertent use of 1,064 nm Q-switched Nd:YAG laser.

Diagnostic utility of melanin production by fungi: Study on tissue sections and culture smears with Masson-Fontana stain.

Background: Dematiaceous fungi appear brown in tissue section due to melanin in their cell walls. When the brown color is not seen on routine H and E and culture is not available, differentiation of dematiaceous fungi from other fungi is diffi cult on morphology alone. Aims and Objective: To study if melanin production by dematiaceous fungi can help differentiate them from other types of fungi. Materials and Methods: Fifty tissue sections of various fungal infections and 13 smears from cultures of different species of fungi were stained with Masson Fontana stain to assess melanin production. The tissue sections included biopsies from 26 culture-proven fungi and 24 biopsies of fi lamentous fungi diagnosed on morphology alone with no culture confi rmation. Results: All culture-proven dematiaceous fungi and Zygomycetes showed strong positivity in sections and culture smears. Aspergillus sp showed variable positivity and intensity. Cryptococcus neoformans showed strong positivity in tissue sections and culture smears. Tissue sections of septate fi lamentous fungi (9/15), Zygomycetes (4/5), and fungi with both hyphal and yeast morphology (4/4) showed positivity for melanin. The septate fi lamentous fungi negative for melanin were from biopsy samples of fungal sinusitis including both allergic and invasive fungal sinusitis and colonizing fungal balls. Conclusion: Melanin is produced by both dematiaceous and non-dematiaceous fungi. Masson-Fontana stain cannot reliably differentiate dematiaceous fungi from other fi lamentous fungi like Aspergillus sp; however, absence of melanin in the hyphae may be used to rule out dematiaceous fungi from other fi lamentous fungi. In the differential diagnosis of yeast fungi, Cryptococcus sp can be differentiated from Candida sp by Masson-Fontana stain in tissue sections.

Malignant melanoma of the mandibular gingiva: A rare occurrence.

Primary mucosal malignant melanoma of the oral cavity is a rare tumor. It accounts for only 0.2-8% of all malignant melanomas. This malignancy commonly affects male subjects and is more frequently seen on the hard palate and maxillary gingiva. The peak age for diagnosis of oral melanoma is between 55 and 65 years. A biopsy is required to establish a diagnosis. Ablative surgery with tumor-free margins remains the treatment of choice. It has a much poorer prognosis than its counterpart on the skin. Here, we present a case of malignant melanoma of the mandibular lingual gingiva in a 55-year-old male patient. Immunohistochemistry and special stains were conducted for confirmatory diagnosis.