Germ cell tumors and leukemia

LE-ITERS TO THE EDITOR GERM

CELL

TUMORS

AND

LEUKEMIA

To the Editor: Dr. Brox and his colleagues described a patient with mediastinal germ cell tumor that expressed common acute lymphoblastic leukemia-associated antigen (CALLA) antigen (Am J Med 1986; 80: 1249-1252). Larsen et al [I] described a patient in whom acute lymphoblastic leukemia developed seven months after the diagnosis of mediastinal germ cell tumor. Cells resembling lymphoblasts were noted in the original tumor. Special stains were not performed. Development of acute lymphoid or myeloid leukemia after the diagnosis of mediastinal germ cell tumor has been reviewed [2]. We have recently reported another case and postulated that there is an embryologic link between leukemia and mediastinal germ cell tumor [3]. Therefore it is not surprising that CALLA antigen can be found in these tumors. It would be extremely interesting to follow the patient closely for the developement of leukemia in the future. JONATHAN

C. YAU,

M.D.,

F.R.C.P

(C.)

309 22 Sir Winston Churchill Avenue St. Albert, Alberta Canada T8N 184 1. Larsen 2.

3.

M, Evans WK, Shephard FA, et al: Acute lymphoblastic leukemia. Possible origin from a mediastinal germ cell tumor. Cancer 1984; 53: 441-444. Nichols CR, Hoffman R, Einhorn LH, et al: Hematological malignancies associated with primary mediastinal germ cell tumors, Ann Intern Med 1985; 102: 603-609. Reynoso E, Yau J, Shephard F, et al: Acute leukemia and mediastinal teratocarcinoma. Proc Am Sot Clin Oncol 1986: 5: 97.

Submitted

September

3, 1986,

and accepted

September

DOES MARIJUANA SMOKING REDUCE MONOXIDE DIFFUSING CAPACITY?

18, 1986

CARBON

study, the mean carbon monoxide diffusing capacity in marijuana-plus-tobacco smokers was within normal limits, and the number of marijuana cigarettes smoked was higher (mean 32 cigarette-years) (data pending publication). Our data, along with those previously reported by Tashkin et al [2], suggest that marijuana smoking by itself does not cause a significant reduction in carbon monoxide diffusing capacity and that the reduction found in some marijuanaplus-tobacco smokers is not correlated with the amount of marijuana smoked. There can be several explanations for these discrepancies. To begin with, the persons these studies evaluated have been very distinct. Tilles et al studied women only, whereas male subjects predominated in our and Tashkin et al’s studies. This difference can be important, since carbon monoxide diffusing capacity is more reduced in female that in male tobacco smokers [3]. Therefore, this same difference could exist between male and female marijuana-plustobacco smokers. Second, the predicted values employed by Tilles et al are the highest among the reported [4] and this undoubtedly contributes to a decline in the mean carbon monoxide diffusing capacity. In fact, their nonsmoker control group had a mean value of 92 percent whereas this should be closer to 100 percent. Finally, the authors did not mention if subjects that smoked other illicit drugs had been excluded. This information is important, since cocaine smoking, for example, can cause carbon monoxide diffusing capacity reductions [6]. It is difficult to interpret results when dealing with such a small number of subjects, so further studies should be made to clear up these discrepancies and to verify if there are actual differences between male and female marijuana-plus-tobacco smokers. SEBASTIAN de 10s SANTOS-SASTRE, M.D. Department of Pulmonary Medicine Virgen del Rocio Hospital of the Spanish Social Security Seville, Spain 1.

To the Editor: I have read with great interest a recent article by Tilles et al (Am J Med 1986; 80: 601-606) in which the effects of marijuana smoking on lung function were analyzed. A marked reduction in carbon monoxide diffusing capacity was found in a group of seven marijuana-plus-tobacco smokers. These findings are surprising when compared with reports by other investigators as well as with a study presently being carried out in our hospital. Tashkin et al [l] found a higher percentage of abnormal carbon monoxide diffusing capacity values in a group of marijuana-plus-tobacco smokers than in another group that smoked marijuana only. However, the mean values of carbon monoxide diffusing capacity were within normal limits in both groups. The number of marijuana cigarettes smoked was similar in both of these groups and practically the same as in the marijuana-plus-tobacco smokers group in the study of Tilles et al (mean 24.5 cigarette-years). In our January

2.

3.

4.

5.

Tashkin DP, Coulson A, Spivey G, et al: Lung function in habitual, heavy smokers of marijuana with and without tobacco (abstr). Am Rev Respir Dis 1984; 129 (suppl): A141. Tashkin DP, Shapiro BJ, Lee YE, Harper CE: Subacute effects of heavy marijuana smoking on pulmonary function in healthy men. N Engl J Med 1976; 294: 125-129. Enjeti S, Hazelwood 8, Permutt S, Menkes H, Terry P: Pulmonary function in young smokers: male-female differences. Am Rev Respir Dis 1978; 118: 667-676. Crap0 RO, Morris ‘AH: Standardized single,breath normal values for carbon monoxide diffusing capacity. Am Rev Respir Dis 1981; 123: 185-190. ltkonen J, Schnoll S, Glassroth J: Pulmonary dysfunction in “ireebase” cocaine users. Arch Intern Med 1984; 144: 2195-2197. Submitted

July 8, 1986,

and accepted

September

2, 1986

The Reply: The single-breath diffusing capacity for carbon monoxide is a moderately sensitive test for damage to the gas exchange surface of the lung, but there is considerable spread in the

1987

The

American Journal

of

Medicine

Volume

82

183