A 69-year-old woman was admitted to our hospital because of dizziness. Brain CT and MRI revealed a cerebellar tumor with hemorrhage, as well as multiple small brain tumors (fig. ). The cerebellar tumor was resected because of the hemorrhage, while the other tumors were treated using Gamma-Knife radiosurgery. Adenocarcinoma was strongly suspected on pathological examination (fig. ); however, the primary tumor site was unidentifiable. Serum carcinoembryonic antigen (CEA) and sialyl Lewis X antigen (SLX) levels were 129.9 ng/ml and 150 U/ml, respectively. Other tumor markers were within the reference range. Malignancy was not detected in the mammary glands, or in gynecological or gastroenterological areas. Chest CT revealed enlarged submandibular (only the right side), infraclavicular, and subcarinal lymph nodes (fig. ). Fluorodeoxyglucose (FDG) positron emission tomography revealed high FDG uptake in these lymph nodes (maximal standardized uptake values of 3.8, 8.2, and 10.2, respectively; fig. ). The resected tumor was positive for napsin A and thyroid transcription factor-1 (TTF-1) (fig. ); an epidermal growth factor receptor (EGFR) exon 19 deletion mutation was also detected. These findings led us to strongly suspect lung adenocarcinoma (cTxN3M1b, stage IV). Thus, gefitinib (250 mg/day) treatment was initiated.
a Brain CT showing cerebral tumor with hemorrhage. b T2-weighted MRI image of the brain.
Fig. 2 Microscopic appearance of the cerebellar tumor specimen. a Tumor cells showing papillary and ductal arrangement (H&E staining). b Tumor cell nuclei and cytoplasm stained with adenocarcinoma cocktail antibodies comprising TTF-1 and napsin A antibodies. (more ...)
Fig. 3 Chest CT on admission (a–c) and on day 19 (d–f) of the chemotherapy course. a, d Right submandibular lymph node (arrows). b, e Right infraclavicular lymph node (arrows). c, f Subcarinal lymph node (arrows). g FDG positron emission tomography (more ...)
On day 19 of the therapy, chest CT revealed 60% shrinkage in lymph node volume (fig. ), particularly in the subcarinal lymph nodes. On day 46, serum CEA and SLX levels were 11.6 ng/ml and 29 U/ml, respectively.