Related Experiment Video For SMARCB1
Updated: Feb 5, 2026

Development of Compendium for Esophageal Squamous Cell Carcinoma
Published on: April 12, 2024
SMARCB-1 deficient squamous cell carcinoma of a mediastinal cyst
Yuuki Nishimura1, Akihiko Yoshida1, Kan Yonemori2
1Department of Pathology and Clinical Laboratories, National Cancer Center Hospital, Tokyo, Japan.
Abstract:
SMARCB1-deficiency has been found in a variety of tumors. Here, we report a SMARCB1-deficient squamous cell carcinoma of a mediastinal cyst. A 53-year-old man was diagnosed with a cyst of the pericardial region in his twenties. As a symptom at this time, he complained of severe pain and dyspnea in the right chest. Following investigation using imaging and histological examination of the biopsy specimen, he was diagnosed with a SMARCB1 deficient malignant neoplasm. As tumor cells showed positive immunostaining for p40 and CK5/6, the immunophenotype of the tumor was consistent with squamous cell carcinoma (SCC). The patient died six months after initial presentation. The autopsy showed the most part of the tumor with anaplastic cytomorphology, loss of SMARCB1, diffusely positive immunostaining for pancytokeratin, and negative immunostaining for p40 and CK5/6. To our knowledge, this is the first report of SMARCB1-deficient SCC of mediastinal cyst.
Related Concept Videos
SN1 Reaction: Stereochemistry
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
SN1 Reaction: Kinetics
However, Sir Christopher Ingold and Edward D. Hughes, who studied the kinetics of various nucleophilic substitution reactions, noticed that a tertiary alkyl halide does undergo a nucleophilic substitution reaction in the presence of a weak nucleophile. While studying the substitution...
SN1 Reaction: Mechanism
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a...
Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
Predicting Products: SN1 vs. SN2
With increased substitution on the alkyl halide,...
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...

