We report a rare case of vaginal amelanotic melanoma. Malignant melanomas are cutaneous and extracutaneous tumors that arise from embryological remnants of neural crest cells/melanocytes. Amelanotic melanomas at such rare locations can be misdiagnosed both clinically and radiologically. Therefore, histopathological examination and immunohistochemistry are mandatory for the diagnosis of these tumors. We diagnosed this case using histopathology and confirmed the diagnosis based on the presence of immunohistochemical markers human melanoma black 45 (HMB45) and S-100.
Diagnosis ; Humans ; Immunohistochemistry* ; Melanoma ; Melanoma, Amelanotic* ; Neural Crest ; Vagina

No abstract available.
Melanoma, Amelanotic* ; Poroma*

Amelanotic melanoma comprises only 1.8~8.1% of malignant melanomas, and is difficult to diagnose clinically due to the lack of the diagnostic evidence of clinical pigmentation. To our knowledge, it is rarely reported, and only 10 cases have been reported in the Korean dermatological literature. It presents rather conflicting features such as a pink or red macule, papule, plaque, or nodule mimicking various benign and malignant conditions; therefore, it is difficult to diagnose. We performed a review of six patients with amelanotic melanoma focusing on differential diagnosis, particularly at the time of the initial visit. Clinical impressions included pyogenic granuloma, dermatofibrosarcoma protuberans, eccrine poroma, epidermal cyst, keloid, pilomatricoma, and squamous cell carcinoma in addition to malignant melanoma. The biopsy specimens were consistent with malignant melanoma with little or no melanin pigment on hematoxylin and eosin and Fontana-Masson stains. Four of the six patients were positive for S-100 and HMB-45, but two patients were positive for S-100 only. We report these cases to remind clinicians of the necessity of including malignant melanoma in the differential diagnosis process when patients show poor and unpredictable responses to treatment after a clinical diagnosis of other benign and malignant conditions.
Biopsy ; Carcinoma, Squamous Cell ; Coloring Agents ; Dermatofibrosarcoma ; Diagnosis ; Diagnosis, Differential* ; Eosine Yellowish-(YS) ; Epidermal Cyst ; Granuloma, Pyogenic ; Hematoxylin ; Humans ; Keloid ; Melanins ; Melanoma ; Melanoma, Amelanotic* ; Pigmentation ; Pilomatrixoma ; Poroma

Amelanotic acral melanoma is rare and difficult to diagnose, both clinically and pathologically. KIT mutations are frequently found in acral melanomas and are considered a risk factor for poor prognosis. The presence of vitiligo in melanoma has been reported, and KIT is thought to be partly responsible for the dysfunction and loss of melanocytes observed in vitiligo. We report a case of amelanotic subungual melanoma with multiple metastases that was associated with KIT mutation and vitiligo. An 85-year-old man presented with a 3-year history of a tender erythematous ulcerated tumor on the left third fingertip and developed hypopigmented patches on the face and trunk. Histopathological examination of the ulcerative tumor showed aggregates of tumor cells that were pleomorphic epithelioid cells. Immunohistochemical staining of the tumor cells was positive for S100, HMB45, and c-Kit. Histopathological findings from the hypopigmented patch on the face were consistent with vitiligo. Mutation analysis showed a KIT mutation in exon 17 (Y823D). The patient had metastasis to the brain, liver, bone, and both lungs. The patient refused chemotherapy, and died 3 months after the first visit.
Aged, 80 and over ; Brain ; Drug Therapy ; Epithelioid Cells ; Exons ; Humans ; Liver ; Lung ; Melanocytes ; Melanoma* ; Melanoma, Amelanotic ; Neoplasm Metastasis ; Prognosis ; Risk Factors ; Ulcer ; Vitiligo*

No abstract available.
Heel* ; Melanoma, Amelanotic* ; Ulcer*

Amelanotic maliganat melanoma is a comparatively rare disease. It accounts for 1.8~8.1% of all malignant melanoma. It is sometime difficult to diagnose amelanotic malignant melanoma because there is no pigmentation, clinically. Polypoid melanoma is a variant of nodular melanoma, which in depth seldom reaches the reticular dermis. The main part of the tumor is located above the nearby epidermis, raised in the form resembling cauliflower. We report a rare case of amelanotic malignant melanoma with polypoid feature in a 78-year-old woman who presented a single bright red nodule on the left thigh.
Aged ; Brassica ; Dermis ; Epidermis ; Female ; Humans ; Melanoma ; Melanoma, Amelanotic ; Pigmentation ; Rare Diseases ; Thigh

Primary malignant melanoma of the uterine cervix is a rare neoplasm with poor prognosis. It may be misdiagnosed especially when amelanotic, in which case immunohistochemistry is useful in reaching the diagnosis. We present one such case of a 65-year-old postmenopausal female patient presenting with bleeding per vaginum. Speculum examination revealed an ulcero-proliferative growth involving the cervix. On histopathological examination it was originally suspected to be a poorly differentiated carcinoma or a non-epithelial malignant tumor, but was subsequently correctly diagnosed by immunohistochemical staining with the HMB-45 antibody and S-100 protein.
Aged ; Cervix Uteri ; Female ; Hemorrhage ; Humans ; Immunohistochemistry ; Melanoma ; Melanoma, Amelanotic ; Prognosis ; S100 Proteins ; Surgical Instruments ; Uterine Cervical Neoplasms

Amelanotic melanomas comprise only 2% of malignant melanomas and are commonly a difficult clinical diagnosis, due to the lack of melanin pigment typically found in melanomas. Even rarer is the amelanotic malignant melanoma, which may clinically mimic a variety of other less serious cutaneous lesions such as erythema or pruritus, and therefore misdirecting the clinician toward improper treatments and frequently delaying necessary diagnostic biopsy. We report a rare case of amelanotic melanoma occurring in the left retromandibular area with a poor prognosis. A 73-year-old woman presented with a 3-year history of a erythematous lesion in the left retromandibular area. The lesion was surgically removed and biopsy was performed. The biopsy specimen showed atypical, pleomorphic tumor cells with little melanin pigment. On immunohistochemical study, the tumor cells were positive for S-100 protein, HMB-45 and Melan-A. These findings were consistent with amelanotic malignant melanoma. On positron emission tomography/computed tomography (PET/CT), hypermetabolic lesions were found in both the axillary lymph nodes. She was treated with chemotherapy. But four months later, the patient died. Amelanotic melanoma is extremely rare and is more aggressive than pigmented lesions in the similarly stage. The absence of pigmentation in the tumor may result in diagnostic confusion. The clinician should be familiar with the presentation of amelanotic malignant melanoma to facilitate prompt diagnosis. Early diagnosis is crucial since survival is related to tumor thickness and tissue invasion.
Aged ; Biopsy ; Early Diagnosis ; Electrons ; Erythema ; Female ; Humans ; Hydrazines ; Lymph Nodes ; MART-1 Antigen ; Melanins ; Melanoma ; Melanoma, Amelanotic ; Pigmentation ; Prognosis ; Pruritus ; S100 Proteins

Mucosal malignant melanomas (MM) within the nose and paranasal sinuses are rare, representing 1-3% of MM and 3-4% of malignant sinonasal tumors. The incidence of amelanotic MM with primary lesions in the sinonasal cavity is also extremely rare. The absence of pigmentation in the tumor may result in diagnostic confusion. Amelanotic MM may masquerade as a variety of other conditions leading to a delay in the diagnosis and worsen the prognosis. In this report, we present, along a brief review of the literature, an interesting case of amelanotic MM misconceived as a nasal polyp. Although paranasal MRI and endoscopy showed no evidence of remnant mass after surgery, positron emission tomography/computed tomography (PET/CT) image showed an area of increaed fluorodeoxyglucose (FDG) uptake.
Electrons ; Endoscopy ; Incidence ; Melanoma ; Melanoma, Amelanotic ; Nasal Cavity ; Nasal Polyps ; Nose ; Paranasal Sinuses ; Pigmentation ; Prognosis

Primary malignant melanoma of the vagina is extremely rare, accounting for 3% of all primary malignant tumor of the vagina and 0.3~1% of all malignant melanomas in the female. The amelanotic melanoma of the vagina showing no melanin granules on histological examination is exceedingly rare, accounting for only about 10% of all melanoma of the vagina. The amelanotic melanoma of the vagina is often difficult to differentiate from non-epithelial malignant tumor because of the minimal number of melanin granules. We describe a case of primary amelanotic melanoma of the vagina, which was initially suspected to be a non-epithelial malignant tumor, especially malignant peripheral nerve sheath tumor (MPNST), but was correctly diagnosed by HMB-45 antibody and S-100 protein immunohistochemical staining. So we present this case with a brief review of literature.
Accounting ; Female ; Humans ; Immunohistochemistry ; Melanins ; Melanoma ; Melanoma, Amelanotic ; Peripheral Nerves ; S100 Proteins ; Vagina