Search

This unusual case is that of a middle-aged man exhibiting a tumor diathesis including a basal cell adenocarcinoma with features of adenoid cystic carcinoma arising in minor salivary gland of lip in association with multiple primary malignant cylindromas of skin. The labial lesion showed invasive tubules, solid epithelial sheets and cribriform structures. It did not exhibit PAS positive juxta-tubular basement membrane material. The skin lesions all showed features of a highly infiltrative cylindromatous carcinoma with two cell types, peripheral palisading and prominent PAS positive juxta-tubular basement membrane material. Immunocytochemical studies of the lip lesion and one of the skin lesions showed similarities, including positive staining for high and low molecular weight keratins and S-100 with negative staining for CEA. The previous descriptions of tumor diatheses involving dermal cylindromas and dermal analogue tumors of salivary glands and the distinctions with the present study are noted. If benign and even malignant cylindromas were described in the literature to be associated with basal cell adenocarcinoma of the major salivary glands, our case is unique by its association with this rare malignant tumor in a minor salivary gland. [ABSTRACT FROM AUTHOR]

Adenoid cystic carcinoma ( ACC) is a relatively rare slow-growing and often-aggressive epithelial-myoepithelial neoplasm that arises in multiple organs including the skin. The t(6;9) (q22-23;p23-24) translocation, resulting in a MYB-NFIB gene fusion has been found in ACCs from the salivary glands and other organs. Recently, MYB aberrations occurring in a subset (40%) of primary cutaneous ACC ( PCACC) examples was described. Herein, we report three additional cases of PCACC harboring MYB aberrations. The tumors presented in three males aged 43, 81 and 55 years old and affected the extremities in the first two patients and the scalp in the third one. None of the patients had history of prior or concurrent ACC elsewhere. Lesions exhibited the classic ACC morphology of nests of basaloid cells arranged in cribriform and adenoid patterns. Sentinel lymph node biopsy was performed in two cases with one case showing lymph node positivity. Fluorescence in situ hybridization with break-apart probes for MYB and NFIB loci revealed that two cases showed MYB rearrangements while one case showed loss of one MYB signal. None of the cases showed NFIB rearrangements. We contribute with three additional cases of PCACC exhibiting MYB aberrations, the apparent driving genetic abnormality in these tumors. [ABSTRACT FROM AUTHOR]

Background: The evaluation of malignant cutaneous spindle cell tumors is challenged by a diagnostic differential that comprises neoplasms of diverse histogenesis, and a broad immunohistochemical panel may confound the diagnosis when the results suggest multiple lines of differentiation, such as with a combined myofibroblastic and epithelial phenotype. Methods: We report the case of a solitary scalp nodule that quickly became locally metastatic. A comprehensive panel of immunohistochemistry markers and electron microscopy was evaluated to determine the differentiation of the spindle cells. Results: The tumor, consisting of wavy and slender spindle cells with predominantly bland nuclei, showed immunoreactivity to vimentin, smooth muscle actin, and muscle-specific actin. AE1/AE3, CK5/6, and MNF-116 antibodies were weakly positive in rare cells. However, 34βE12 showed diffuse positivity in the spindle cell population, thus supporting the diagnosis of a sarcomatoid carcinoma with myofibroblastic differentiation. Conclusions: The use of 34βE12 is essential for the evaluation of myofibroblastic spindle cell tumors with rare cytokeratin reactivity. However, even with immunohistochemical and electron microscopic studies, the diagnosis of spindle cell tumors can be confounded by the multiplicity of nosologic equivalents, such as carcinosarcoma, spindle cell carcinoma, and metaplastic carcinoma. The nomenclature of these spindle cell tumors is discussed. [ABSTRACT FROM AUTHOR]

Among sarcomas with a round‐cell morphology that lack rearrangement of the EWSR1 gene, rearrangements involving the CIC gene are the most common. In comparison with Ewing Sarcoma, CIC‐rearranged sarcomas present at an older average age, arise almost exclusively in soft tissues, are clinically more aggressive, and are more likely to be resistant to the chemotherapy regimens used for Ewing sarcoma. CIC‐rearranged sarcomas present more commonly in a deep location, and we suspect that superficial presentations may be under‐recognized. In this case series, we report three of such cases. Overall, the morphology is similar to CIC‐rearranged sarcomas of deeper locations. We hope to raise awareness among the dermatopathology community by expanding the differential of superficial tumors with round cell morphology. [ABSTRACT FROM AUTHOR]