bromochloroacetic-acid and Melanoma--Amelanotic

We report a case of a 27-year-old woman with a nonpigmented lesion on the right scalp. Histological examination showed a malignant nodular neoplasm with 2 distinct but intimately admixed components: a malignant melanoma with a spindle component and an unusual glandular component. Immunohistochemical studies demonstrated epithelial differentiation on the basis of cytokeratin (CAM5.2 and AE1/AE3) expression in the glandular component and melanocytic differentiation (HMB-45, PNL2, MITF, and S-100) of the spindle cell component. A single melanocytic marker (MITF) was expressed in both components, raising the possibility of dual differentiation in a single tumor, rather than the alternative considerations of a collision tumor or a reactive pseudoepitheliomatous hyperplasia with eccrine duct lumen formation within a melanoma. This unusual tumor with both melanocytic and epithelial components may represent a true melanocarcinoma, which becomes a plausible consideration, in view of melanoma plasticity and recent experimental evidence and speculation about the role of stem cells in melanoma.

Topics: Adenocarcinoma; Adult; Cell Differentiation; Epithelial Cells; Female; Humans; Immunohistochemistry; Keratins; Melanocytes; Melanoma, Amelanotic; Microphthalmia-Associated Transcription Factor; Neoplasms, Glandular and Epithelial; Neoplasms, Multiple Primary; Scalp; Skin Neoplasms

A 63-year-old patient with a malignant melanoma of the uterine cervix is described. Subtle epitheliotropism of the neoplastic cells within the endocervical columnar epithelium suggested melanoma in situ and the possibility of a primary uterine cervical melanoma, despite a negative anti-S-100 protein immunohistochemical stain. An exhaustive clinical workup, and ultimately, complete autopsy failed to reveal any other primary tumor site, and the diagnosis of melanoma was confirmed by histology and immunohistochemistry on the hysterectomy specimen. A world literature review revealed 54 previously reported cases of uterine cervical melanoma of which 43 had been reported as primary uterine cervical melanoma. A true intraepithelial melanocytic component was found in only 14 of those cases, however, and none of those reports illustrated this with the clarity with which it was seen in the endocervical glandular and surface columnar epithelium of the present case. Primary uterine cervical melanoma is usually discovered at an advanced stage and is no longer amenable to curative therapy. Even when this tumor is discovered early, however, the diagnosis may be unnecessarily delayed if the often subtle interaction of the neoplastic cells with the benign cervical squamous or glandular epithelium is not appreciated, or if the possibility of malignant melanoma is not entertained based on other histologic or immunohistologic characteristics of the tumor cells.

Topics: Actins; Desmin; Epithelium; Fatal Outcome; Female; Humans; Hysterectomy; Immunohistochemistry; Keratins; Melanocytes; Melanoma; Melanoma, Amelanotic; Middle Aged; Mucin-1; Neoplasm Metastasis; Neoplasm Recurrence, Local; S100 Proteins; Uterine Cervical Neoplasms; Uterine Hemorrhage

Amelanotic malignant melanoma (AMM) is a subtype of cutaneous melanoma with little or no pigment upon visual inspection. The lack of pigmentation is the reason for late diagnosis of lesions and a poor prognosis. We report a case of a 55-year-old female with an AMM diagnosed by immunophenotyping. Monoclonal antibodies S-100, HMB-45, and antibodies to cytokeratin were used. Our patient underwent a wide local excision (a 2 cm wide margin) 2 years ago. So far there are no signs of a recurrence. In doubtful cases, immunophenotyping with monoclonal antibodies HMB-45 and S-100 is important for confirming the correct diagnosis of AMM.

Topics: Antibodies; Antibodies, Monoclonal; Combined Modality Therapy; Diagnosis, Differential; Female; Humans; Immunophenotyping; Keratins; Melanoma, Amelanotic; Middle Aged; S100 Proteins; Skin Neoplasms

A 3-year-old, neutered, male Golden Retriever was presented for evaluation of a 10 X 9 X 5 mm, firm, red, raised, cutaneous mass located over the left cranial thorax and noted incidentally by the owner. On cytologic evaluation of a fine-needle aspirate of the mass, the interpretation was a malignant tumor with predominantly mesenchymal features. Differentials included liposarcoma, atypical amelanotic melanoma, anaplastic sarcoma, and anaplastic carcinoma. Following complete excision of the mass, a diagnosis of sebaceous adenocarcinoma was made based on histologic features, positive immunostaining for pancytokeratin, and negative staining for vimentin, Melan-A, and S-100. There was no evidence of metastasis on physical examination or thoracic radiographs, and the prognosis was good. The unique and previously unreported cytologic features of this small, sebaceous adenocarcinoma were the extreme pleomorphism, including marked anisocytosis, anisokaryosis, and multinuclearity, and the paucity of epithelial features.

Topics: Adenocarcinoma, Sebaceous; Animals; Carcinoma; Diagnosis, Differential; Dog Diseases; Dogs; Immunohistochemistry; Keratins; Liposarcoma; Male; Melanoma, Amelanotic; Sebaceous Gland Neoplasms

Topics: Antigens, Neoplasm; Ciliary Body; Humans; Immunoenzyme Techniques; Iris Neoplasms; Keratins; Male; Melanoma-Specific Antigens; Melanoma, Amelanotic; Middle Aged; Neoplasm Proteins; Neoplasms, Unknown Primary; Ultrasonography

The authors retrospectively tested the potential value of paraffin-reactive monoclonal antibodies (A103 against melan-A, T311 against tyrosinase) and antibody KBA62 as immunohistochemical markers for amelanotic metastatic melanomas. The study cases included 72 amelanotic metastases of known cutaneous melanomas, 59 poorly differentiated carcinomas, 73 sarcomas of varying histogenesis, 4 Leydig cell tumors, 10 high-grade lymphomas, and 6 plasmoblastic/anaplastic myelomas. The results were compared with immunostainings for S-100 protein and HMB-45. HMB-45, antimelan-A, and antityrosinase showed almost identical staining results, with a sensitivity of 0.85 for HMB-45 and of 0.86 for both antimelan-A and for antityrosinase. HMB-45 and antityrosinase both had a specificity of 1.00; the specificity of antimelan-A was 0.95 as a result of a positive reaction in three of three adrenocortical carcinomas and four of four Leydig cell tumors. KBA62 stainings resulted in a sensitivity of 0.86 for melanomas. A positive immunoreactivity of KBA62 alone had a specificity of only 0.83, but in conjunction with anti-S-100 protein (sensitivity, 1.00; specificity, 0.87) and anticytokeratin 8/18/19 (CK), a KBA62+/S-100+/CK- immunophenotype identified all except one of the melanoma cases that were negative for the three melanocyte-specific markers with a specificity of 0.99. In conclusion, we found comparable immunohistochemical sensitivities of HMB-45, antityrosinase, and antimelan-A for a highly specific identification of approximately 85% of amelanotic metastatic melanomas on paraffin sections. Melanomas that were negative for all of these specific markers might be sensitively and specifically detected with anti-S-100 protein and KBA62.

Topics: Antibodies, Monoclonal; Antigens, Neoplasm; Biomarkers, Tumor; Humans; Immunohistochemistry; Keratins; MART-1 Antigen; Melanoma-Specific Antigens; Melanoma, Amelanotic; Monophenol Monooxygenase; Neoplasm Proteins; Paraffin; S100 Proteins; Staining and Labeling