Abstract and Introduction
Worldwide, marijuana (cannabis) is a widely used drug. The incidence of marijuana smoking is increasing and is second only to tobacco as the most widely smoked substance in the general population. It is also the second most commonly used recreational drug after alcohol. Some adverse effects of marijuana smoking have been documented; however, the number of studies on the pulmonary effects of marijuana in individuals with leukemia is limited. In our case series, we report on 2 men with acute myeloid leukemia with miliary nodular lung patterns on computed tomography of the chest due to heavy marijuana use. We also report on 2 patients with acute lymphocytic leukemia who had a history of smoking marijuana and then developed lung opacities consistent with mold infection.
Use of marijuana (cannabis) is common by many people worldwide.The incidence of marijuana smoking is increasing, second only to tobacco as the most widely smoked substance in the general population. It is also the second most commonly used recreational drug after alcohol.As of publication, 23 states plus the District of Columbia allow marijuana to be used as a medicinal drug and 4 states have passed measures to make its recreational use legal.[4,5] However, the US Drug Enforcement Administration still considers marijuana to be a schedule 1 substance. Marijuana is a greenish-gray mixture of the dried, shredded leaves, stems, seeds, and flowers of Cannabis sativa. Preparations of C sativa have been used for their euphoric effects. The most psychoactive constituent compound in marijuana is tetrahydrocannabinol (THC), which is rapidly absorbed from the lungs and binds to endogenous cannabinoid receptors in the central nervous system.
The potency of THC in marijuana has risen from approximately 4% in the early 1980s to as much as 30% in the 2000s. The most common method of marijuana use is smoking, either as a rolled cigarette (joint), through a water-filled pipe (bong), or the hookah, with coal used to vaporize water and then mixed with tobacco. The bong is considered the most harmful method. Marijuana can be inhaled up to the peak inspiration, holding the hot fumes for as long as possible prior to slow exhalation. Such smoking technique results in a greater deposition of toxic substances, such as tar and carbon monoxide, as well as damage to the lung parenchyma typically seen in those who smoke tobacco cigarettes.[10–12]
The gaseous and particulate composition of marijuana is similar to tobacco cigarettes, except that the active component in tobacco is nicotine (compared with THC in marijuana). An accurate study of adverse effects of marijuana is difficult to perform due to its illegal status in many states, various smoking techniques, and its shorter duration of use compared with tobacco. In addition, tobacco smoking is frequently a confounding factor in marijuana studies, although some pulmonary adverse effects of marijuana smoking have been documented and include cough, dyspnea, bronchitis, pneumomediastinum, spontaneous pneumothorax, and apical lung bullae.[15–18]
Marijuana mold contamination has also been reported. The association between nodular pneumonia and bronchiolitis, with its associated miliary micronodular pattern, and smoking marijuana has been described in the literature. However, the effect of marijuana smoking in immunocompromised populations has not been studied, except for a few case reports.
Cancer Control. 2016;23(3):278-283. © 2016 H. Lee Moffitt Cancer Center and Research Institute, Inc.
Copyright by H. Lee Moffitt Cancer Center & Research Institute. All rights reserved.