ABSTRACT
INTRODUCTION: Polymorphous low-grade adenocarcinoma (PLGA) occurs more frequently in minor salivary glands. The diagnosis of PLGA, in general, is not difficult but in occasional tumors showing limited invasion or in small biopsy specimens, PLGA may be confused with cellular pleomorphic adenoma (PA). Plasmacytoid cells, a usual component of PAs, have been considered helpful for correct tumor identification. OBJECTIVE: The aim of this study was to verify the frequency (if any) of plasmacytoid-type cellular differentiation (PD) in PLGA. MATERIALS AND METHODS: Thirty-two cases of PLGA were reviewed. PD was recognized in 2 cases (6.25%), in which immunohistochemical expression of AE1/AE3, CK7, CK14, vimentin, α-SMA, p63, S-100, calponin, GFAP, and Ki-67 was evaluated. RESULTS: The 2 cases presented conventional areas of PLGA and variable quantities of cells with PD forming aggregates in the stroma and lining ductal structures. Cells with PD showed positivity for AE1/AE3, CK7, S-100, and vimentin and were negative for CK14, calponin, and GFAP in both cases. In case 1, cells with PD did not present α-SMA and p63 positivity whereas in case 2 they were positive, but for α-SMA such reactivity was restricted to cells forming solid aggregates. CONCLUSION: Although PD in PLGA is rare, it is necessary to be aware of this possibility, particularly in small incisional biopsies and in PLGA with limited invasion, to avoid confusion with cellular PA.
Subject(s)
Adenocarcinoma/pathology , Salivary Gland Neoplasms/pathology , Adenocarcinoma/diagnosis , Adenoma, Pleomorphic/diagnosis , Adenoma, Pleomorphic/pathology , Biomarkers, Tumor/analysis , Cell Differentiation , Diagnosis, Differential , Female , Humans , Immunohistochemistry , Male , Middle Aged , Salivary Gland Neoplasms/diagnosisABSTRACT
UNLABELLED: The synchronous occurrence of two different neoplasias is an uncommon event, which may arise between tumors originating in the same organ or in cancer-to-cancer metastasis. We report a rare case of chronic lymphocytic leukaemia / small lymphocytic lymphoma associated with a cutaneous metastatic squamous cell carcinoma in a cervical lymph node. In the affected lymph node, it was observed an effacement of the normal architecture by neoplastic lymphocytes and it was noted the presence of neoplastic invasive epithelial islands. Immunohistochemical analysis demonstrated that lymphocytic proliferation was positive for CD20, CD5, CD23 and Kappa, and negative for CD3, CD10, Cyclin D1 and Lambda. The morphological and immunohistochemical profile lead to a phenotype of B-cell chronic lymphocytic leukaemia / small lymphocytic lymphoma. The epithelial cells were positive for CK5, thus rendering the diagnosis of synchronous metastatic cutaneous squamous cell carcinoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma. Literature supports the poor prognosis in cases that present coexistence of squamous cell carcinoma and chronic lymphocytic leukaemia / small lymphocytic lymphoma. Thus, it is necessary to be aware about this unusual finding in order to provide specific treatment. KEY WORDS: Chronic lymphocytic leukaemia, small lymphocytic lymphoma, squamous cell carcinoma, metastasis.