Intraoral Pigmented Low-Grade Adenocarcinoma, Not Otherwise Specified: Case Report and Immunohistochemical Study

Construction of hematoxylin-eosin, immunohistochemistry, and EBER-ISH methodology after trichloroisocyanuric acid treatment in melanin-containing tissues

This study investigated the effects of trichloroisocyanuric acid (TCCA) on the bleaching and morphology of melanin-containing pathological sections. The pathological sections of 27 patients with high melanin content were bleached with 0.5% potassium permanganate, 10% hydrogen peroxide, and different concentrations of TCCA. Significant differences were found among the blank control group, 1% TCCA group (P < 0.0001). The hematoxylin-eosin (HE) score of the "recovery pH" HE staining group after treatment with 1% TCCA was similar to that of the "Conventional HE" scheme group (P > 0.05). The morphological diagnostic scores of 50 cases of pathological sections with different melanin content before and after TCCA bleaching were compared. The results showed a significant difference in the diagnostic score between the middle- and high-melanin content groups before and after 1% TCCA bleaching (P < 0.05). Immunohistochemical staining was performed on meningeal melanoma tissue. For this, 8% TCCA solution was used to remove melanin after Ki67, S100, and β-catenin immunohistochemical staining. After bleaching with TCCA, the staining and positioning of each marker with different localization were accurate and the background was clear. The same results were also shown with EBER-ISH. This study concluded that 1% TCCA could be used for HE staining of pathological sections containing melanin, and "restore pH" HE scheme as the staining method after TCCA melanin removal. Further, 8% TCCA was used for bleaching after immunohistochemical DAB staining. Melanin can be completely removed, and sections can meet diagnostic needs.

Adenocarcinoma not otherwise specified (NOS) arising in the sublingual gland: Rare case report and follow-up

BACKGROUND

Adenocarcinoma not otherwise specified (AdCaNOS) is a rare malignant salivary gland tumor that occurs with higher frequency in the parotid gland of male patients. In this study, we described a second case of AdCaNOS arising in the sublingual gland, in a female patient with 39 years of age, highlighting the clinical, radiographic, microscopic, treatment features and follow-up.

CASE REPORT

A 39-year-old female patient presented a fibroelastic nodule with a yellowish coloration, in the left region of the floor of mouth, measuring about 4.0 cm in its largest diameter. An incisional biopsy was performed and the main microscopic features revealed an infiltrative lesion with glandular differentiation organized in cystic spaces, where neoplastic cells secreting eosinophilic material were observed. The tumor showed immunopositivity for pancytokeratin (AE1/AE3), keratins 7 (CK7) and 14 (CK14), and negativity for p63. The proliferation level measured by Ki-67 marker was considered higher. The patient underwent radical surgical resection, but unfortunately, she developed local recurrence, lymph node mestastasis and died 1.5 year after diagnosis.

CONCLUSION

Although rare in the sublingual gland, particularly at this age, AdCaNOS can occur and early diagnosis and early treatment are essential for a better prognosis and survival rates of the patients.

Co-expression of Myoepithelial and Melanocytic Features in Carcinoma Ex Pleomorphic Adenoma

The presence of melanin pigment and melanocytic markers expression have been rarely reported in salivary gland tumors. Herein, two cases of carcinoma arising in pleomorphic adenoma of the parotid gland and showing diffuse expression of myoepithelial and melanocytic markers are described. The clinical-pathological clues useful in the differential diagnosis with melanoma are discussed. In addition, a review of the pertinent literature is also proposed, discussing the pathologic mechanisms potentially involved in this phenomenon.