Lymphadenowhat?, may be the reaction from a patient or clinician upon reading a diagnosis of cutaneous lymphadenoma or lymphoepithelial tumor of the skin. Not to be confused with lymphoepithelioma-like carcinoma of the skin. This tumor is thought to be a variant of trichoblastoma (trichoblastoma with adamantinoid features).
Lymphadenomas are rare, but typically occur on the face of patients in their 40s and 50s. Nose seems to be a great place to get one of these, as that is where the lymphadenomas I have seen came from. Full disclosure, this biopsy recently came from the nasal root of a patient in their 50s, but I included a photo I took years ago of a lymphadenoma from the nose.
Histology: The tumor shows lobular and trabecular nests of basaloid cells within a fibrotic stroma. The nests are rimmed by basaloid cells. Some of the nests show infiltration by small lymphocytes and larger histiocytoid cells with abundant cytoplasm. I have never performed immunohistochemsitry on one of these, but reports show S100 and CD1a staining cells within the nests. CD30 positive cells have also been reported, which may be histiocytes or activated lymphocytes. The small lymphocytes are usually predominantly T-cells with some B-cells. The infiltrate within the epithelial nests is not as extensive in this biopsy as in others I have seen.
J Cutan Pathol. 1999 Mar;26(3):119-24. Immunohistochemical comparison of cutaneous lymphadenoma, trichoblastoma, and basal cell carcinoma: support for classification of lymphadenoma as a variant of trichoblastoma. McNiff JM, Eisen RN, Glusac EJ.