Detection of melanin in the rat skin.

Melanogenesis disorder is called dyschromia, is involved in various conditions including vitiligo, solar lentigo, and melanoma, the last of which is the most malignant type of skin cancer. AIM: The aim of study was focused on histological visualization of melanogenic system. MATERIALS AND METHODS: To investigate the roles of melanocytes and melanin, we used a rat skin as an experimental animal. Samples were stained using hematoxylin-eosin, the Schmorl's technique, the Fontana-Masson technique, the Warthin-Starry technique, and the S100 immunohistochemistry marker technique. Microscopy images were analyzed using the ImageJ free software protocol. RESULTS: We found Fontana-Masson staining to be the most suitable for obtaining reliable results compared with the other methods, which had more disadvantages. We also found the S100 marker staining to be an effective tool for measuring the melanocyte count. CONCLUSIONS: We consider the ImageJ processing protocol and staining procedures to be useful tools to estimate melanin and melanocyte pathology.

Fontana-Masson stain in fungal infections.

BACKGROUND: Fontana-Masson (FM) staining is a histopathology technique used to identify dematiaceous fungi. The result often guides initial species identification and antifungal treatment; however, there is evidence that nondematiaceous fungi might react with this stain. Few studies in the current literature address this issue. OBJECTIVE: Our aim was to classify the FM staining patterns of common fungal pathogens for use by pathologists attempting to accurately identify fungi on histopathologic examination. METHODS: In total, 132 cases of culture proven mycoses were identified. We stained tissue with 2 different FM protocols and recorded the intensity and distribution of results. RESULTS: There was variability in staining, and many nondematiaceous fungi showed positivity, including Zygomycetes, Aspergillus, and Fusarium spp. LIMITATIONS: The study was limited by the number of cases. Of 132 cases identified, 112 cases had adequate tissue left after sectioning deeper into the block. CONCLUSION: Nondematiaceous fungi frequently stained positive with FM. The course of treatment should not be based on the result of this stain alone. Histopathology should be examined in multiple tissue sections, and therapy should be determined on the basis of clinical context and culture results.

Melanin fate in the human epidermis: a reassessment of how best to detect and analyse histologically.

Melanin is the predominant pigment responsible for skin colour and is synthesized by the melanocyte in the basal layer of the epidermis and then transferred to surrounding keratinocytes. Despite its optical properties, melanin is barely detectable in unstained sections of human epidermis. However, identification and localization of melanin is of importance for the study of skin pigmentation in health and disease. Current methods for the histologic quantification of melanin are suboptimal and are associated with significant risk of misinterpretation. The aim of this study was to reassess the existing literature and to develop a more effective histological method of melanin quantification in human skin. Moreover, we confirm that Warthin-Starry (WS) stain provides a much more sensitive and more specific melanin detection method than the commonplace Fontana-Masson (FM) stain. For example, WS staining sensitivity allowed the visualization of melanin even in very pale Caucasian skin that was missed by FM or Von Kossa (VK) stains. From our reassessment of the histology-related literature, we conclude that so-called melanin dust is most likely an artifact of discoloration due to non-specific silver deposition in the stratum corneum. Unlike FM and VK, WS was not associated with this non-specific stratum corneum darkening, misinterpreted previously as 'degraded' melanin. Finally, WS melanin particle counts were largely similar to previously reported manual counts by transmission electron microscopy, in contrast to both FM and VK. Together these findings allow us to propose a new histology/Image J-informed method for the accurate and precise quantification of epidermal melanin in skin.

Follmann balanitis - A very rare presentation of primary syphilis.

Syphilis is a sexually transmitted infection caused by Treponema pallidum. The primary stage of the disease manifests as a chancre. Balanoposthitis as a presenting feature of primary syphilis is a very rare presentation. A 26-year-old male presented with asymptomatic erythematous plaques involving the glans and prepuce after unprotected intercourse with a known female. Routine investigations, serology, and dark field examination were normal. Fontana-Masson stain revealed spirochetes and a diagnosis of syphilitic balanitis of Follmann was entertained. This rare presentation accounts for only 0.3%-0.5% of cases of primary syphilis and hence is highlighted in this case report.

Pigmented lateral periodontal cyst: A case report and review of pigmented odontogenic cysts.

Pigmented odontogenic cysts are uncommon and to date, only 37 cases have been reported in the English literature. Here, we report a case of a pigmented lateral periodontal cyst (LPC) in the maxilla of a 48-year-old female. The patient presented with clinical swelling in the maxillary anterior region. Microscopic features of the biopsied specimen were consistent with a diagnosis of LPC. The epithelial cyst lining exhibited numerous coarse granules of melanin pigment, which was confirmed by S-100 immunohistochemistry and Fontana-Masson bleach histochemical method. Almost all documented cases of pigmented odontogenic cysts have occurred in Asians and African-Americans, with only three cases in white patients. Racial pigmentation may have a role in the pathogenesis of these lesions. Although the origin and pathologic significance of melanocytes in these pigmented intraosseous lesions cannot be explained, it may be something to consider for investigation in future.

Round Cell Vaginal Malignant Melanoma: A rare entity.

Malignant melanoma is predominantly a skin disease but in rare instances it may occur at other sites. A vaginal melanoma is a rare clinical entity and the round cell type is an uncommon variant. Although the present case was clinically diagnosed as a urethral caruncle, on histopathological examination and immunostaining it was diagnosed as a round cell pigmented malignant melanoma. The patient refused radical surgery and was given a full course radiotherapy treatment but died a year later. Malignant vaginal melanoma carries a very poor prognosis even when lesion is localised at the time of presentation. The five-year survival rate ranges from 10-20% with the prognosis being influenced by tumour size. A tumour size ≥3cm has a poor prognosis. Age, mitotic count, stage, and location of the lesion do not influence survival rates.

Congenital systemic melanosis in a black mongrel pig / 대한수의학회지

Four 3-day-old piglets with retarded growth were submitted to the Animal and Plant Quarantine Agency for diagnosis. Necropsy showed that one piglet had black spots ranging from 2 mm to 1 cm in diameter in the cerebellum, lungs, regional lymph nodes, and cecum. Histological findings were consistent with the gross appearance in which melanin pigmentation was observed in the organs mentioned above. Based on Fontana-Masson staining, we diagnosed this animal with systemic melanosis. To the best of our knowledge, this is the first case of systemic melanosis in black breeds of swine in Korea.

The Correlation of the Expression of Foxn1 and the Pigmentation in Various Pigmentary Disorders / 대한피부과학회지

BACKGROUND: Transfer of melanosomes from melanocytes to the neighboring keratinocytes is a critical step in normal pigmentation. However, the mechanism of melanosome transfer and the regulation of pigmentation by the keratinocyte-melanocyte interactions are not well understood. It has recently been identified that keratinocytes use Foxn1 (transcription factor) to recruit melanocytes and induce their own pigmentation. OBJECTIVE: The purpose of this study was to assess the expression of Foxn1 in hypopigmentary disorders (vitiligo, pityriasis alba (P. alba) and postinflammatory hypopigmentation (PIHo)) and hyperpigmentary disorders (melasma, caf?-au-lait macule (CALM) and postinflammatory hyperpigmentation (PIHer)). METHODS: Immunohistochemical staining was performed on the formalin-fixed, paraffin-embedded tissue sections of hypopigmentary and hyperpigmentary disorders using anti-Foxn1 antibody with an avidin-biotin peroxidase complex procedure. The intraepidermal melanin pigments were examined in all the lesions by Fontana-Masson staining. RESULTS: We found a significantly lower Foxn1 expression (p<0.05) and less intraepidermal melanin pigments (p< 0.01) in the hypopigmentary disorders as compared to that of the hyperpigmentary disorders. In the hypopigmentary disorders such as vitiligo, P. alba and PIHo, the expression of Foxn1 was decreased in the order named. In thehyperpigmentary disorders such as CALM, PIHer and melasma, the expression of Foxn1 was increased in the order named. CONCLUSION: The intraepidermal Foxn1 expression and melanin pigments in PIHer, PIHo and melasma showed a positive correlation, but there was no statistically significant. Our findings suggest that the expression of Foxn1 might be associated with the pathogenesis of three pigment disorders (PIHo, PIHer, melasma). We consider that inflammatory mediators might interact with the intraepidermal Foxn1 expression in PIHo, PIHer and melasma, resulting in an abnormality of the mechanism of melanosome transfer. Further studies are warranted to elucidate the role of the Foxn1 expression in the pathogenesis of pigment disorders.

Histopathology, serology and cultures in the diagnosis of cryptococcosis / Histopatologia, sorologia e cultivo no diagnóstico da criptococose

Cryptococcosis is one of the most common opportunistic fungal infections in patients with acquired immunodeficiency syndrome (AIDS). We report 13 cases of cryptococcal infection based on histopathology, serology and cultures. Epidemiological analysis, histochemical techniques of hematoxilin and eosin (HE) and Grocot's silver (GMS), as well special histochemical techniques such as Mayer's mucicarmine (MM) and Fontana-Masson (FM), cryptococcal antigen test (CrAg) and isolation on fungal media: Sabouraud's (SAB), brain-heart infusion agar (BHI) and canavanine-glycine-bromothymol blue (CGB) agar were analyzed. Unsatisfactory staining results by MM stain associated to negative titers by CrAg test, which FM stain confirmed that capsule-deficient Cryptococcus infections were observed in four cases. Eight isolated cases were identified as follows: six cases were infection with Cryptococcus neoformans and two cases were Cryptococcus gattii.

A criptococose é a mais comum infecção fúngica oportunística observada em pacientes com síndrome da imunodeficiência adquirida (AIDS). Relatamos 13 casos da infecção baseados no diagnóstico histopatológico, sorológico e cultivo. Foram analisadas: a epidemiologia, as técnicas histoquímicas básicas de hematoxilina-eosina (HE) e coloração pela prata (GMS), bem como as técnicas histoquímicas especiais de mucicarmim de Mayer (MM) e Fontana-Masson (FM), o teste do antígeno criptocóccico (CrAg) e o isolamento em cultivos em ágar-Sabouraud (SAB), ágar infusão de cérebro-coração (BHI) e meio com canavanina azul de bromotimol (CGB). Em quatro casos, resultados tintoriais insatisfatórios pela coloração de MM associados a títulos negativos pelo teste do CrAg, a coloração de FM confirmou a infecção pelo Cryptococcus deficiente de cápsula. Oito isolados foram identificados: seis casos apresentaram a infecção por Cryptococcus neoformans e dois casos apresentaram a infecção por Cryptococcus gattii.

Value of Histological Staining in Differential Diagnosis of Vitiligo / 대한피부과학회지

BACKGROUND: Vitiligo is a depigmented disorder, causing serious cosmetic problems for patients. In diagnostic and therapeutic aspects, vitiligo should be differentiated from other hypopigmented disorders as the therapeutic approach and prognosis are different for each disease. OBJECTIVE: This study aimed to compare the usefulness of several markers for melanocytes or melanin in differential diagnosis of vitiligo. METHODS: Twenty-eight patients were studied, who were diagnosed clinically as suffering from one of the following diseases: vitiligo, nevus depigmentosus, pityriasis alba, postinflammatory hypopigmentation, and idiopathic guttate hypomelanosis. Skin samples (frozen or paraffin-fixed) were obtained from depigmented patches and normal neighboring skin (control). Histological staining was performed by using Fontana-Masson, S-100, MART-1, and DOPA. The staining level of lesional skin was compared with that of normal skin. RESULTS: When the staining level of vitiligo was compared with that of others, vitiligo was significantly lower in Fontana-Masson (13.3+/-17.2% vs 44.4+/-23.7%), S-100 (49.5+/-14.9% vs 74.7+/-24.2%), MART-1 (7.4+/-8.7% vs 68+/-33.9%), and DOPA (9.5+/-11.3% vs 58.2+/-29.5%) (p<0.0001). CONCLUSION: MART-1 and DOPA are valuable markers in differential diagnosis of vitiligo. However, Fontana-Masson, a marker of melanin, had some limits in detecting melanocytes, and S-100 showed non-specific staining other than melanocytes.

Técnicas histopatológicas no diagnóstico de criptococose por Cryptococcus deficiente de cápsula: relato de caso / Histopathological techniques for diagnosing cryptococcosis due to capsule-deficient Cryptococcus: case report

Caso de criptococose por Cryptococcus deficiente de cápsula, no qual cultivo do espécime clínico e pesquisa do antígeno capsular no líquor e soro foram negativos. As técnicas histopatológicas foram: Hematoxilina-eosina, Grocott, Mucicarmim de Mayer e Fontana-Masson. Confirmou-se o diagnóstico do Cryptococcus deficiente de cápsula pela técnica de Fontana-Masson e pela imunofluorescência direta. É discutida a potencialidade das técnicas histoquímicas.

A case of cryptococcosis due to capsule-deficient Cryptococcus is presented, in which culturing of the clinical specimen and tests for capsular antigen in cerebrospinal fluid and serum were negative. The histopathological techniques evaluated were hematoxylin-eosin, Grocott methenamine silver, Mayer’s mucicarmine and Fontana-Masson. The diagnosis of cryptococcosis due to capsule-deficient Cryptococcus was confirmed by means of the Fontana-Masson technique and by direct immunofluorescence. The potential of the histochemical techniques is discussed.

A Case of Pulmonary Cryptococcosis by Capsule-deficient Cryptococcus neoformans

Pulmonary infection by capsule-deficient Cryptococcus neoformans (CDCN) is a very rare form of pneumonia and it is seldom seen in the immunocompetent host. The authors experienced a case of pulmonary cryptococcosis by CDCN in 25-year-old woman who was without any significant underlying disease. The diagnosis was made from the percutaneous lung biopsy and special tissue staining, including Fontana-Masson silver (FMS) staining. Fungal culture confirmed the diagnosis afterward. Her clinical and radiologic features improved under treatment with fluconazol. It's known that CDCN is not so readily confirmed because fungal culture does not always result in growth of the organism and the empirical fungal stain is not helpful for the differentiation between CDCN and the other infections that are caused by the nonencapsulated yeast-like organisms. In this report, we emphasize the diagnostic value of performing FMS staining for differentiating a CDCN infection from the other confusing nonencapsulated yeast-like organisms.

Two Cases of Dyschromatosis Symmetrica Hereditaria / 대한피부과학회지

We report two cases of dyschromatosis symmetrica hereditaria. One is a 12-year- old female and her family had five individuals with similar pigmentary disorder through three generation. The other is a 22-yesr-old female who had no family history of similar disease. Fontana-Masson stain revealed increased and decreased melanin granules in the basal cell layers in the pigmented and depigmented lesions respectively.

A Case of Dermal Melanocyte Hamartoma / 대한피부과학회지

Dermal melanocytosis is characterized by the presence of ectopic melanocytes in the dermis. Dermal melanocytosis assumes several morphologic forms, including the Mongolian spot, the blue nevus, the nevus of Ota, the nevus of Ito and dermal melanocytic hamartoma. Differential diagnostic features of these dermal melanocytic lesions depend on onset, course, distribution, histologic features, uniformity of pigmentation, etc. In our case, an 18-year-old girl had asymptomatic 5x3cm sized ill-defined bluish patch on left forearm since birth. Histologic examinations revealed marked increased infiltrate of pigment cells mainly in the upper dermis in Hematoxylin & eosin stain . Fontana-Masson stain and Gp 100 stain revealed marked infiltrate of melanin-containing cells in upper dermis. We report a rare case of dermal melanocyte hamartoma.

A Conjunctival Malignant Melanoma Involving the Cornea

In a case of conjunctival malignant melanoma involving the cornea, we evaluated the findings of H,E, Fontana-Masson, S-100 protein, HMB 45 stain after the localized excision in 39 years old male patient. B-scan ultrasonography, orbit, MRI, Ga citrate scanning and bone scan showed no metastasis to the intraocular tissue, orbital adnexae and other organs. In H-E stain, spindle cells containing melanin pigment which was growing diffusely underneath the conjunctival epithelium could be seen. Fontana-Masson and S-100 protein staining resulted in diffusely positive findings, Therefore we could diagnose as 8 spindle B type malignant m.elanom.a. By histopathological examination, in a case of confirmed spindle B type COunctival malignant melanoma involving the cornea, good result, could be obtained by localized excision followed by 11 months.