[Three Cases of Appendiceal Goblet Cell Adenocarcinoma in Our Institution].

Appendiceal goblet cell adenocarcinoma(AGCA)is a newly designated pathological term adopted in the 5th edition of the WHO classification. It is synonymous with goblet cell carcinoid, which was previously categorized as a part of appendiceal carcinoid. However, since 2018, it has been classified as a subtype of adenocarcinoma. We have experienced 3 cases of this relatively rare tumor, of which 2 were initially diagnosed with acute appendicitis and were diagnosed with AGCA by pathological examination after an emergency appendectomy. Each of them underwent additional ileocolic resection with lymph node dissection as the second surgery. In the 3rd case, an appendiceal tumor was detected during preoperative examinations for an ovarian tumor. Staging laparoscopy revealed comorbid peritoneal dissemination, and only the appendix and right ovary were removed in the consecutive surgery. The ovarian tumor was pathologically diagnosed as a metastasis of AGCA. In this case, the introduction of oxaliplatin-based systemic chemotherapy after surgery achieved a complete response after more than 2 years. Although no recurrence has been observed in all 3 cases to date, AGCA is considered highly malignant compared to conventional appendiceal carcinoids. Therefore, it is crucial to practice multidisciplinary treatments, including sufficient radical surgery based on a precise diagnosis of AGCA, as is performed for advanced colorectal cancer.

Benefit of Continuation of Low-Dose Imatinib for Gastrointestinal Stromal Tumors despite Adverse Events with Regular-Dose Imatinib.

Tyrosine kinase inhibitors (TKIs) such as imatinib improve the prognosis of patients with gastrointestinal stromal tumors (GISTs). However, treatment options for GISTs are still limited, and the continuation of TKIs is difficult due to adverse events in some cases. The effectiveness of low-dose imatinib is unclear. We report 2 cases to show effectiveness of low-dose imatinib in patients with adverse events. The first case is a male in his early 60s with a history of intestinal GIST resection who was diagnosed with recurrent GIST with peritoneal dissemination. He was started on low-dose imatinib (300 mg) because of a history of subconjunctival hemorrhage after receiving postoperative imatinib. Follow-up contrast-enhanced ultrasonography revealed that the tumors had shrunk in size and number after 2 months of treatment with 300-mg imatinib. He continued this treatment and showed partial response for 8 months. The second case is a female in her late 70s with rectal GIST who was treated with imatinib 400 mg. Due to a severe skin lesion, she changed her treatment to sunitinib 2 months after initiation. However, new metastasis in the liver was confirmed after 4 months of administration of sunitinib. She underwent surgical esection of the rectal tumor to reduce the volume. After the surgery, low-dose imatinib (300 mg) with oral steroids was adopted. Follow-up confirmed the absence of recurrence at the rectum and no increase in hepatic tumor size for 18 months. Aggressive treatment with low-dose imatinib instead of discontinuation or alteration of treatment may benefit patients with unresectable and postoperative GISTs with sensible mutation to imatinib.

Brain and Adrenal Metastasis From Unknown Primary Tumor: A Case Report.

The clinical management of brain metastasis (BM) and adrenal metastasis (AM) of cancer of unknown primary (CUP) can be challenging. A 73-year-old man presented to the hospital with sudden-onset hemiplegia. His laboratory data were normal, except for elevated levels of carcinoembryonic antigen (CEA) (33.8 ng/mL). Contrast-enhanced magnetic resonance imaging revealed a 2-cm mass with ring enhancement in the right parietal lobe and extensive vasogenic edema around the tumor. The lesion was diagnosed as BM; however, we could not detect the primary origin by fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT). Stereotactic radiotherapy was then administered, resulting in reduced tumor size and relief of symptoms. Follow-up after one year revealed an elevated CEA level (148.6 ng/mL) and remarkable fluorodeoxyglucose (FDG) uptake in the right adrenal gland, with an area of enhancement of 20 mm, on FDG-positron emission tomography computed tomography, with normal findings in other distant organs. He underwent adrenalectomy, and the adrenal tumor was diagnosed as a poorly differentiated adenocarcinoma likely of lung origin based on the histopathologic and immunohistochemistry findings of cytokeratin (CK) 7 (+), CK 20 (-), thyroid transcription factor-1 (TTF-1) (+), inhibin (-), napsin A (+), prostate-specific antigen (PSA) (-), caudal type homeobox 2 (CDX-2) (-), synaptophysin (-), and p40 (-). Metastatic tumors of unknown primary origin remain latent. Aggressive treatment of these lesions can be beneficial for symptom relief, diagnosis, and prolongation of survival.