Pigmented squamous cell carcinoma with dendritic melanocyte colonization in the external auditory canal

Pigmented apocrine hamartoma: A distinct and uncommon pigmented lesion with dendritic melanocytes and appraisal of terminology

A 20-year-old female presented to a gynecologist with an irregular, darkly pigmented, vulvar lesion. Histopathologic sections of a biopsy specimen showed cystically dilated glands with apical snouts, pigmented secretion, and numerous dendritic melanocytes. The lesion was diagnosed as a pigmented apocrine hamartoma of the vulva. We report the fifth case of this uncommonly encountered entity and discuss the conflicting terminology in the literature of this rare, pigmented lesion.

Clinicopathological and immunohistochemical characteristics of pigmented oral squamous cell carcinoma

Pigmented oral squamous cell carcinoma (POSCC) is a rare and underrecognized pathological variant of oral squamous cell carcinoma (OSCC). The current study aimed to evaluate the clinicopathological characteristics, treatment outcomes and prognosis of patients with POSCC and to investigate its oncological properties using immunohistochemical studies. A total of 1,512 patients were pathologically diagnosed with squamous cell carcinoma of the oral cavity, and were treated at the Department of Oral and Maxillofacial Surgery, Tokyo Medical and Dental University between January 2001 and December 2018. A total of 25 patients had POSCC and underwent radical surgery. Of these 25 patients, 23 presented with early T stage disease. Additionally, 22 patients were negative for cervical lymph nodes metastasis. Only one patient had local recurrence. The 5-year disease-free and disease-specific survival rates were 86.6 and 95.8%, respectively. Immunohistochemically, a high percentage of POSCC exhibited low p53 and Ki-67, preserved E-cadherin or negative vimentin expression. The results suggested that POSCC tends to exhibit non-aggressive oncological behavior and demonstrates a good prognosis.

Clinicopathologic features and pathogenesis of melanocytic colonization in atypical meningioma

Only two prior cases of benign dendritic melanocytes colonizing a meningioma have been reported. We add a third case, describe clinicopathologic features shared by the three, and elucidate the risk factors for this very rare phenomenon. A 29 year-old Hispanic woman presented with headache and hydrocephalus. MRI showed a lobulated enhancing pineal region mass measuring 41 mm in greatest dimension. Subtotal resection of the mass demonstrated an atypical meningioma, WHO grade II, and the patient subsequently underwent radiotherapy. She presented 4 years later with diplopia, and MRI showed an enhancing extra-axial mass measuring 47 mm in greatest dimension and centered on the tentorial incisura. Subtotal resection showed a brain-invasive atypical meningioma with melanocytic colonization. The previous two cases in the literature were atypical meningiomas, one of which was also brain invasive. Atypical meningiomas may be at particular risk for melanocytic colonization as they upregulate molecules known to be chemoattractants for melanocytes. We detected c-Kit expression in a minority of the melanocytes as well as stem cell factor and basic fibroblast growth factor in the meningioma cells, suggesting that mechanisms implicated in normal melanocyte migration may be involved. In some cases, brain invasion with disruption of the leptomeningeal barrier may also facilitate migration from the subarachnoid space into the tumor. Whether there is low-level proliferation of the dendritic melanocytes is unclear. Given that all three patients were non-Caucasian, meningiomas in persons and/or brain regions with increased dendritic melanocytes may predispose to colonization. The age range spanned from 6 years old to 70 years old. All three patients were female. The role of gender and estrogen in the pathogenesis of this entity remains to be clarified. Whether melanocytic colonization may also occur in the more common Grade I meningiomas awaits identification of additional cases.

Pigmented squamous cell carcinoma in situ of the conjunctiva in 5 cases

PURPOSE

To describe 5 patients with pigmented conjunctival squamous cell carcinoma in situ.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Five patients.

METHODS

Clinical and histopathologic features were reviewed.

MAIN OUTCOME MEASURES

Relationship of clinical and histopathologic features to carcinoma pigmentation.

RESULTS

All 5 patients were male. Two were Hispanic, 2 were Caucasian, and 1 was Asian Indian. Localized racial melanosis was evident in 3 cases and no case showed diffuse racial melanosis. The tumor showed leukoplakia (n = 1) and was at the temporal limbus (n = 4) or nasal limbus (n = 1). The mean tumor basal dimension was 9.2 mm and mean thickness was 3.2 mm. Brown pigment was present deep within the tumor in all 5 cases, involving 50% to 90% of the mass. In each case, pigmented squamous cell carcinoma was suspected; melanoma was a second possibility. Histopathology revealed in situ squamous cell carcinoma (conjunctival intraepithelial neoplasia) with pigmented dendritic melanocytes in all 5 cases. Pigment was also found within neoplastic cells (n = 2). After surgical resection, there was no recurrence over mean follow-up of 23 months.

CONCLUSIONS

Squamous cell carcinoma in situ can manifest as a pigmented tumor, resembling melanoma, in both Caucasians and non-Caucasians, primarily due to intratumoral pigmented dendritic melanocytes.

Pigmented oral squamous cell carcinoma: a case report and brief review of the literature

Melanin impregnation in squamous cell carcinoma (SCC) is an uncommon histological finding. Rare nonmelanocytic entities were previously described as having melanocyte colonization. A 57-year-old Brazilian woman was referred with a pigmented lesion in the lower lip and alveolar ridge with a prior clinical diagnosis of melanoma. The incisional biopsy of the tumor revealed an SCC with strong colonization of melanocytes in the stroma. The authors report a case of an unusual SCC variant and a brief review of the literature.

Pigmented Squamous Cell Carcinoma

Although dendritic, melanin-containing melanocytes can be seen in a variety of epithelial neoplasms, only 0.01% to 7% of all squamous cell carcinomas (SCC) are pigmented. Furthermore, most reported cases have occurred in the oral and ocular mucosa, with relatively few cases reported to originate in the skin. Herein we report a case of a 61-year-old Caucasian male who presented with a large blue-black nodule on his left cheek, clinically suspicious for a melanoma; however, histological evaluation revealed an acantholytic pigmented squamous cell carcinoma. Previous cases are reviewed and the clinical and histological differential diagnoses are discussed.

Pigmented squamous cell carcinoma of the uterine cervix

A 57-year-old female presented with an abnormal Pap smear. Colposcopic examination of the cervix revealed white mucosa with erosion and several areas of black pigmentation. After a colposcopically directed biopsy and loop conization, radical hysterectomy and bilateral salpingo-oophorectomy with pelvic and paraaortic lymphadenectomy were performed. Pathological examination disclosed an invasive squamous cell carcinoma admixed with many dendritic melanocytes. Melanin granules were present within the melanocytes and tumor cells. Although similar tumors have been reported in other sites, this is the first report to our knowledge of a pigmented squamous cell carcinoma of the uterine cervix.

Pigmented squamous cell carcinoma of the cheek skin probably arising from solar keratosis

We report a rare case of pigmented squamous cell carcinoma (SCC) of the cheek skin probably arising from solar keratosis. An 80-year-old man was referred to our clinic because of a black skin nodule in the right cheek. The nodular lesion was 1 cm in diameter, dome-shaped, hard, sharply demarcated, partially erosive and telangiectatic at the border. The lesion was completely excised under the clinical diagnosis of probable seborrheic keratosis. Microscopically, cutaneous horn and mildly atypical squamous epithelia suggestive of previous solar keratosis were present in the surface of the lesion. The lesion consisted of atypical squamous cells with keratinization and intercellular bridges, and it was regarded as SCC. The SCC cells were seen to invade lightly into the upper dermis, where lymphocytic infiltrations and melanophages were noted. Characteristically, heavy deposition of melanin pigment was recognized in the SCC cells as well as in proliferated dendritic and pigment blockade melanocytes that were scattered or colonized within the SCC cell nests. Masson-Fontana stain revealed numerous melanin granules in the SCC cells, as well as in dendritic and pigment blockade melanocytes. Immunohistochemically, the SCC cells were positive for cytokeratins and epithelial membrane antigen, and negative for S-100 protein and HMB45 antigen. Dendritic and pigment blockade melanocytes were negative for cytokeratins, epithelial membrane antigen, and HMB45 antigen, but positive for S-100 protein. The present case suggests that SCC cells of the skin may induce proliferation of melanocytes. The differential diagnosis and the histogenesis of pigmented SCC of the skin are discussed.

Melanocytic colonization of a meningothelial meningioma: histopathological and ultrastructural findings with immunohistochemical and genetic correlation: case report

OBJECTIVE AND IMPORTANCE

Melanocytic colonization of nonpigmented extracranial tumors has been reported in adenocarcinomas, squamous cell carcinomas, skin appendage tumors, and dermatofibrosarcoma protuberans. To our knowledge, melanocytic colonization of a meningioma has not previously been described.

CLINICAL PRESENTATION

We report an unusual case of a 70-year-old African-American woman who presented with a large frontoparietal meningioma that extended through the calvarium.

INTERVENTION

Craniotomy with gross total resection of the tumor was performed. Histochemistry, immunocytochemistry, ultrastructural analysis, and molecular genetic study via fluorescence in situ hybridization confirmed melanocytic colonization of a meningothelial meningioma.

CONCLUSION

With the inclusion of meningothelial meningioma, the spectrum of tumors affected by melanocytic colonization continues to expand.

Pigmented Bowen's disease (squamous cell carcinoma in situ): a mimic of malignant melanoma

BACKGROUND

Darkly pigmented individuals may manifest unusual or uncharacteristic presentations of various skin conditions, including heavy pigmentation of cutaneous tumors.

OBJECTIVE

To increase the awareness of an unusual presentation of Bowen's disease in a darkly pigmented individual.

METHODS

We report the case of a 52 year old black woman that presented with a lesion clinically consistent with malignant melanoma. However, histopathologic examination revealed pigmented Bowen's disease.

RESULTS

A biopsy is almost always indicated to confirm the diagnosis of lesions in darkly pigmented individuals.

CONCLUSION

This case is presented to reinforce the idea that pigmented Bowen's disease should be considered in the differential diagnosis of malignant melanoma.