176 PROGRESS OF MICROSCOPICAL SCIEHCE. 



Tlie Development of Cancer. — In the 'Medical Record' (Feb. 12) 

 Dr. C. Creightou gives a valuable account of Dr. Carmalt' s recent 

 researches on this point, which are published in Virchow's ' Archiv.' 

 (vol. 58.) The writer records the results of the examination of three 

 carcinomatous tumours, removed from the skin of the nose, the cheek, 

 and the eyelid. Thiersch, in his work on cancer, has pointed out 

 that the epithelial cells of the sebaceous and sweat glands, and espe- 

 cially the cells of the rete Malpighii, are often the point of departure 

 for cancer of the skin, and he casually includes the epithelium and 

 the hair-follicles in the same category. In the hair-follicles Dr. 

 Carmalt found not only an increase of the outer layer of epithelium, 

 but also offshoots from the follicles, diverticula lined with epithelium, 

 penetrating the connective tissue to various depths and in various 

 directions. A section made either obliquely or parallel to the axis of 

 the follicle, and passing through the diverticula, gave exactly the 

 appearance of the ordinary cancer-alveoli, filled with epithelial cells. 

 In certain preparations, it was possible to see the alveolar groupings 

 of the cells pass into long processes lined with epithelium, which, 

 again, opened into the hair-follicle ; so that the appearance was that of 

 a group of acinous glands with their excretory duct. Other sections 

 presented a still more complete picture, viz. the enlarged follicles 

 and their offshoots, the alveolar groups of epithelial cells, evidently 

 in connection with the follicular offshoots, and lastly, isolated 

 epithelial alveoli, situated more deeply in the tissues, and showing the 

 ordinary characters of cancer-alveoli. Carmalt thinks it is hardly to 

 be doubted that these isolated cancer-alveoli were also originally in 

 continuity with the hair-follicles and their diverticula. The sebaceous 

 glands were found unchanged, or hyperplastic, or quite undistinguish- 

 able, according to the degree of invasion of the cancerous growth. 

 The connective tissue (stroma) surrounding the follicles and their 

 abnormal offshoots was at some points so infiltrated with small round 

 and spindle-shaped cells, that the cancer-alveoli could not be dis- 

 tinguished ; at other points, the stroma consisted of a delicate network. 

 In showing that the epithelium of the hair-follicles form a point of 

 departure for the cancerous growth, Carmalt thinks that some light 

 has been thrown on the cause of cancer of the skin. Referring to the 

 statement of Fiihrer, that frequent and rough shaving is apt to pro- 

 duce cancer of the skin of the face, he points out that, out of fifty or 

 sixty cases of cancer of the lip and cheek that have occurred within a 

 recent period in the Breslau Pathological Institute, only two were in 

 women, and not a single case occurred in men with unshaved beards. 

 With reference to the general question of the histological origin of 

 cancer, his conclusions are so far in support of the opinion of 

 Waldeyer and others, that every cancerous growth originates in the 

 epithelial elements of the part, and are in opposition to the opinion of 

 Yirchow, that the cancer-cells are the equivalents of connective tissue 

 corpuscles. In cancer of the oesophagus, Carmalt found an analogous 

 condition. Sections showed processes of the deeper epithelial layer 

 (corresponding to the rete Malpighii of the skin), penetrating the 

 subjacent tissue. These processes were in connection with the cancer- 



