Stereotactic aspiration combined with gamma knife radiosurgery for the treatment of cystic brainstem metastasis originating from lung adenosquamous carcinoma: A case report

Intestinal obstruction caused by primary adenosquamous cell carcinoma of the small intestine: A case report and review of the literature

Primary adenosquamous cell carcinoma (ASCC) arising from the ileum is an exceptionally rare malignant neoplasm exhibiting mixed glandular and squamous differentiation. The clinicopathological characteristics of ASCC have not been clearly determined due to its rarity. We herein report a case of a 74-year-old man with a successfully treated ASCC of the ileum. The patient visited a medical clinic due to abdominal pain. Abdominal computed tomography imaging revealed an intestinal tumor in the ileum. Prior to undergoing capsule endoscopy, the patient complained of severe abdominal pain due to intestinal obstruction from the patency capsule and the tumor. Thus, the patient was referred to our hospital for emergency surgery. Upon relieving the obstruction by partial resection of the ileum, an impacted patency capsule with a tumor with ulceration was identified. On histological examination, the tumor consisted of malignant glandular and squamous cell elements. The postoperative course was uneventful, without complications. The patient subsequently received adjuvant chemotherapy with oxaliplatin and capecitabine for 6 months. The patient has no evidence of recurrence 20 months after surgery. To the best of our knowledge, only 8 cases of ASCC have been reported in the English literature to date. This case serves as an important reminder to consider small intestinal carcinoma, including ASCC, in the differential diagnosis of intestinal obstruction.

Research progress of the clinicopathologic features of lung adenosquamous carcinoma

Adenosquamous carcinoma (ASC) of the lung, a biphasic malignant tumor arising from lung tissue, is a special subtype of non-small-cell lung cancer (NSCLC) with low incidence but high tendency of invasion and poor prognosis. ASC contains components of lung adenocarcinoma (AC) and lung squamous cell carcinoma (SCC). However, there is a remarkable difference between ASC and other NSCLCs in clinical features, suggesting that ASC is not a simple mixture of AC and SCC, but is rather a more complex carcinoma with a unique molecular phenotype. At present, the research on ASC is still rare, mostly because of its complicated molecular mechanism and unclear pathological origin. The lack of cognition of ASC limits its early diagnosis and treatment, and a set of mature and effective treatment programs has not been proposed yet. In-depth study of the molecular characteristics and clinical features of ASC will not only help to better understand the scientific issues, including phenotype switching of lung cancer, the origin of tumor development, and tumor heterogeneity, but also contribute to the development of its individualized treatment. This review summarizes the recent studies concerning the clinicopathologic features and the molecular mechanisms of ASC to further facilitate the development of its individualized treatment.

Toxicity of Radiosurgery for Brainstem Metastases

BACKGROUND

Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation-induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a review of all available studies reporting SRS treatment for BSM was performed.

METHODS

Twenty-nine retrospective studies investigating SRS for BSM were reviewed.

RESULTS

The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events, varied from 0 to 9.5% (mean 3.4 ± 2.9%). Overall, the median time to toxicity after SRS was 3 months, with 90% of toxicities occurring before 9 months. A total of 1243 cases had toxicity and location data available. Toxicity rates for lesions located in the medulla were 0.8% (1/131), compared with midbrain and pons, respectively, 2.8% (8/288) and 3.0% (24/811).

CONCLUSIONS

Current data suggest that brainstem substructure location does not predict for toxicity and lesion volume within this cohort with median tumor volumes 0.04-2.8 cc does not predict for toxicity.

Peritoneum as the sole distant metastatic site of lung adenosquamous cell carcinoma: a case report

Background

Peritoneum metastasis of lung cancer is a rare event which, in addition to the peritoneum, usually involves multiple metastatic tissues. Here we report a case of a patient with lung adenosquamous cell carcinoma with the peritoneum as the sole distant metastatic site.

Case presentation

An 82-year-old Han Chinese man, in the teaching profession, was diagnosed with lung adenosquamous cell carcinoma in the upper lobe of his left lung with the involvement of ipsilateral hilar and mediastinal lymph nodes, and was initially staged as IIIa (cT₂N₂M₀). Molecular testing identified a mutation at KRAS G12A. Due to his poor physical condition, our patient was given gamma knife radiotherapy with a total dose of 28.0 Gy. Two weeks later, our patient was diagnosed as peritoneal metastasis identified by using magnetic resonance imaging and confirmed with ascitic cytology and peritoneal histology. No other distant metastatic sites such as liver, brain, bone, paranephroi, and lungs were found. Subsequently, our patient received palliative intraperitoneal chemotherapy, and died within 2 months.

Conclusions

Our patient represented a rare case of lung adenosquamous cell carcinoma harboring the KRAS G12A mutation, which metastasized distantly to the peritoneum only, and progressed rapidly.