Dermoscopy for "true" amelanotic melanoma: a clinical dermoscopic-pathologic case study

Pheochromocytoma is a rare tumor originating from neuroectodermic cells. Only 10% of these tumors are malignant. There are many familial forms of this tumor, including multiple endocrine neoplasia type II, Von Hippel-Lindau syndrome, and neurofibromatosis type I. Skin manifestations of pheochromocytoma are rare, and cutaneous metastasis in patients with multiple endocrine neoplasia IIB has never been described. The case of a patient with multiple endocrine neoplasia IIB who presented malignant pheochromocytoma with multiple cutaneous metastasis is described.     

Regressing seborrheic keratosis - clinically and dermoscopically mimicking a regressing melanoma

The diagnosis of seborrheic keratosis is a clinical diagnosis. In a certain percentage of cases, differential diagnosis between seborrheic keratosis and malignant melanoma is difficult. We describe a case of regressing seborrheic keratosis simulating malignant melanoma. Clinical, dermoscopic and histopathologic examinations were performed for the occurrence of an asymmetric, irregularly demarcated, irregularly pigmented lesion measuring 1.3 x 1.5 cm on the right part of the abdomen in a 76-year-old male Caucasian. In order not to miss melanoma, the excision and histopathologic examination of the lesion with peppering is essential.     

Pigmented primary carcinoma of the breast: a clinical mimic of malignant melanoma

A 68-year-old man had a pigmented tumour in the breast. Although the clinical picture suggested a malignant melanoma, histology revealed that the tumour was a primary ductal carcinoma of the breast. There was no pagetoid cell proliferation in the epidermis. However, tumour nests contained numerous dendritic melanocytes that could survive in the tumour nests without the existence of epidermal keratinocytes. Further immunohistochemical study employing antibodies to melanocyte growth factors demonstrated that anti-basic fibroblast growth factor (bFGF) antibody was the only reagent to show a positive staining for tumour cells. This indicated that the breast cancer cells produced bFGF, which enabled survival of melanocytes within the tumour mass.     

Multiple pigmented trichoblastomas and syringocystadenoma papilliferum in naevus sebaceous mimicking a malignant melanoma: a clinical dermoscopic-pathological case study

We report a case of three distinct adnexal neoplasms associated with a naevus sebaceous of the scalp: a nodular pigmented trichoblastoma, a smaller flat pigmented trichoblastoma and a syringocystadenoma papilliferum, and discuss the clinical and histological features of these neoplasms. The clinical manifestation was suggestive of malignant melanoma, a feature that has never been reported before. For the first time in the literature we describe the case also by means of a noninvasive analysis, i.e. epiluminescence microscopy. In our experience, epiluminescence microscopy does not appear to be more diagnostically accurate than simple clinical examination when diagnosing lesions of the scalp, contrary to other regions.     

Assessing malignant melanoma: a case study

Good history and close physical examination with high index of suspicions allowed us to perform an excisional biopsy which was also adequate for the primary treatment of this superficial malignant melanoma. The diagnosis, management, and followup of melanoma have undergone many changes and updates over the past decade, prompting practitioners to keep abreast of updated techniques on newer guidelines in order to offer excellent quality care.     

Pigmented apocrine hamartoma of the vulva: A case report

We herein report a patient who clinically presented with a pigmented, flat plaque in the vulvar area. Histological examination showed a benign lesion mainly composed of tubular and cystic glands with apocrine differentiation. The most striking histological feature was the deposition of finely granular melanin pigment both in the epithelial cells and in the luminal surface of the glands. In addition, Melan‐A immunostaining showed the presence of numerous melanocytes within the lesion suggesting that the pigment deposition was secondary to colonization of the lesion by melanocytes. We therefore diagnosed this lesion as “pigmented apocrine hamartoma.” To the best of our knowledge only 3 cases of pigmented apocrine hamartoma have been reported in the literature so far.     

The relation between seborrheic keratoses and malignant solid tumours. A case-control study.

In order to establish whether or not here is an association between cancer and intense growth of seborrheic keratosis, the so-called Leser-Trelat sign, we conducted a case control study in which the number and features of seborrheic keratosis in 82 patients with recent solid tumours, were compared with 82 age- and sex-matched controls. Neither numbers nor features of seborrheic keratosis differed significantly in patients and controls. Eruptive seborrheic keratosis was noted in only one patient and one control. This study showed that solid malignancies are not generally associated with an increase in the number or size of seborrheic keratosis lesions, thus suggesting that they are not controlled by a hypothetical secretion of growth factors by tumours. Our results suggest that Leser-Trelat is either a coincidence, or at most a very rare sign of unusual types of cancer. We also showed that multiple cherry angiomas, previously reported to be a paraneoplastic sign, are not regularly associated with solid tumours.     

Pigmented extramammary Paget's disease of the axilla mimicking melanoma: case report and review of the literature

Pigmented Paget's disease is a rare variant that is often confused clinically and histologically with melanoma in situ . Herein, we describe a case of pigmented extramammary Paget's disease involving the axilla of a 79-year-old white male thought initially to represent malignant melanoma clinically and histologically. Review of the literature reveals that pigmented variant of Paget's disease, either mammary or extramammary, could be initially misdiagnosed as melanoma unless this entity is considered in the differential diagnosis, and additional confirmatory studies are performed.     

Prevalence of melanoma clinically resembling seborrheic keratosis: analysis of 9204 cases

OBJECTIVE: To estimate the prevalence of melanoma clinically mimicking seborrheic keratosis. DESIGN: Retrospective review of cases submitted for histological examination with a clinical diagnosis of seborrheic keratosis or with a differential diagnosis that included seborrheic keratosis. SETTING: A tertiary medical care center-based dermatopathology laboratory serving academic dermatology clinics that have a busy pigmented lesion clinic. MATERIALS AND METHODS: A total of 9204 consecutive pathology reports containing a diagnosis of seborrheic keratosis in the clinical information field were identified between the years 1992 and 2001 through a computer database search. Reports with a final histological diagnosis of melanoma were selected for further review and clinicopathological analysis. MAIN OUTCOME MEASURE: Histological diagnosis, which was correlated with the preoperative clinical diagnosis. RESULTS: Melanoma was identified in 61 cases (0.66%) submitted for histological examination with a clinical diagnosis that included seborrheic keratosis. Melanoma was in the clinical differential diagnosis of 31 cases (51%). The remaining lesions had a differential diagnosis of seborrheic keratosis vs melanocytic nevus (17 cases, 28%), basal cell carcinoma (7 cases, 12%), or a squamous proliferation (3 cases, 5%). In 3 cases (5%), seborrheic keratosis was the only clinical diagnosis. All histological types of melanoma were represented. CONCLUSIONS: Our results confirm that melanoma can mimic seborrheic keratosis. These data strongly support the current policy of submitting for histological examination all specimens that have been removed from patients.     

Pigmented mammary Paget's disease mimicking melanoma: report of three cases

Pigmented mammary Paget's disease (PMPD) is a rare subtype of mammary Paget's disease. The differential diagnosis of PMPD and melanoma is difficult clinically and sometimes histopathologically. Here we present three cases of PMPD with a variable-sized lesion. All cases showed an irregular-shaped black-brown macule, one of which was accompanied by nipple retraction. Dermoscopically, all cases showed reticular pigmentation with or without irregular black dots, regression structures and streaks, which were indistinguishable from those of melanoma. In all but one of the cases, preoperative examinations confirmed the presence of a subcutaneous mammary lesion. All patients underwent a total mastectomy with the histopathological results indicating invasive ductal carcinoma. These cases emphasize how difficult it is to distinguish PMPD from melanoma. Dermoscopic features also mimic those of melanoma, but the reticular pigmentation seen in all cases could be a feature specific to PMPD. For suspicious cases, histopathological assessment using immunohistochemistry is highly recommended.     

Pigmented breast carcinoma. A clinical and histopathologic simulator of malignant melanoma

A case of infiltrating breast carcinoma presenting as a pigmented lesion of the areola and nipple is described. The pigmentation was found to be primarily due to interspersed melanocytes and melanophages within the tumor. The histologic criteria and the differential immunohistochemical staining characteristics of melanoma and breast carcinoma are presented. Also emphasized is the difficulty in differentiating pagetoid malignant melanoma and epidermotrophic breast carcinoma.