AB 53. Metastasis of nasopharyngeal carcinoma to the lung difficulties in diagnostic approach
Background: To highlight the difficulty of the diagnostic approach to estimate transbronchial biopsy in a patient with a known history of carcinoma after treatment.
Patients and methods: A 18-year-old man, with a known history of nasopharyngeal carcinoma, presented with dyspnea and chest pain. The X-ray and a computed tomographic (CT) scan revealed a perihilar mass. A transbronchial biopsy was performed. Evaluated microscopically using histochemical and immunohistochemical methods.
Results: The histological examination showed mucinous degeneration of the stroma (due to the prior treatment), with the presence of a few dense lymphocytic infiltrates in the mucosa - a predominance of T-cells lymphocytes (CD3+ >> CD20+) - including identified small or medium-sized cells with aberrant round or oval-shaped nuclei. Also, we observed areas with crash artifacts Immunohistochemically, the carcinoma cells expressed keratins 8/18 and 34BE12, p63 and ki67 (40%), while were negative keratins 5/6 and 7, TTF-1, CD56 and CD30. The histological report confirmed the diagnosis of undifferentiated carcinoma, which based on immunophenotype and clinical history (nasopharyngeal carcinoma) was regarded as disease recurrence.
Conclusions: The careful microscopic observation of biopsy material in combination with the knowledge of the clinical history and the age of the patient make histological diagnosis. The absence of clear invasive lesion in the material, having the information of history, impose further investigate with immunohistochemical methods. The use of the standard panel of antibodies (keratin 5/6, 7, CD56 and TTF-1) without the expected results (negative), require more careful assessment of data and expansion of immunohistochemical indicators needed to exclude malignancy. The size of the biopsy material is a prerequisite for better assessment. Also special emphasis on the fact of prior therapy, which complicates the evaluation of the material due to the presence of reduced numbers of tumor cells, and degenerative changes of the stroma.
