Neurofibroma, Plexiform Neuroma, and Amputation Neuroma. — Neurofi broma may develop as an overgrowth of the endoneurium„ the perineurium, or even the epineurium.
Multiple neuromata of the skin are known as molluscum fibrosum. Over 2000 of these small tumors may exist along the course of the different nerves involved.
Plexiform neuroma shows tortuosity and increase in size of the nerve-bundles. The classical case of Bruns in his Bei &age z. klin. Chir., vol. viii, '91, occurred on the back of a youth aged 19 years.
Neuromata appear on the ends of nerves after injury, especially after am putations. They may reach the size of a cherry, and are often so painful as to demand resection or reamputation of the limb in which they occur. They are composed of connective tissue and out growths of the ends of the axis-cylinders.
Angiomata and Lymphangiomata. Angiomata, popularly spoken of as strawberry patches, consist in a dilata tion and the reproduction of new blood vessels, the whole growing so as to give rise to a reddish and but slightly ele vated tumor. Lymphangiomata show a similar dilatation of the lymphatics. They are most frequently congenital, though their growth takes place in later life. A careful examination of the face and neck will often reveal a slightly ele vated reddish point, with three or four zigzag and overdilated capillaries. When in this stage they are easily destroyed. Later they undergo proliferative changes and extend in area. When once started, they may involve as much as half the face and neck and give rise to consider able disfigurement. They are composed of capillaries and veins, proliferation of the arteries not taking place.
Mibelli (Arch. f. Dermat., vol. xlv, p. 357) describes a condition which he calls angiokeratoma; it may be looked upon as a combination of a simple wart and a superficial angioma. The neo plasms are multiple, and occur almost always on the back of the hands and the feet.
Cavernous angiomata occur in the skin and the subcutaneous tissue, but more frequently in the liver, where the tissue resembles that of the cavernous body of the urethra. Hfemorrhoids are sometimes classed among the angiomata, but they are mechanical in their forma tion, due to interference with the circu lation, and can hardly be considered as tumors proper, though bunches are some times seen as large as a fist.
There is a peculiar form of racemose arterial angioma in which the arteries of a certain branch become dilated. To the finger these vessels feel like a mass of worms. When lymphangioma affects
the tongue, the condition is known as macroglossia; when the cheek is diseased, it is called macrocheilia.
Many varieties of nwvi, sun-spots, freckles, and moles often have as their basis a lymphangiomatous condition. Unna, Kromayer, Delbanco, and Schen ber (Arch. f. Dermat., vol. xliv, p. 175) are of the opinion that the cell-nests in the cellular nevi come from the epithe lial layers, while Ziegler and others con sider that they originate in the con nective tissue. One reason for this belief is the fact that they nndergo sarcoma tous and not cancerous changes.
II. Epithelial (Organoid) Tumors.
Papilloma.—The ordinary wart as it appears on the hand is a papillomatous growth composed of dense connective tissue containing blood-vessels and cov ered with epithelial cells. Lanz (Dent. med. Woch., No. 20, '99) has experiment ally proved the possibility of the trans plantation of warts. They may be as large as the fist. Warts are found on mucous membranes, and when in the bladder they are spoken of as villous tu mors. Small pieces of these tumors are sometimes passed in the urine. Haemor rhage may be excessive. Intracystic villous papillomata occur in the breast and ovary.
Cutaneous Horns.—Cutaneous horns are objects of curiosity and popular dread among the common people, and I are often seen in museums. They are due to the escape of the contents of a seba ceous cyst, which becomes dried and is pushed further out by its collection of new material.
Epithelioma. — An epithelioma is a proliferation of stratified epithelium which has broken through the basement membrane, and in these situations shows the presence of epithelial nests. These tumors are peculiarly liable to occur in those places where one kind of epithe lium joins another, as at the junction of the mucous membrane of the eye, mouth, or anus with the skin. The term epithelioma is often used as a synonym for cancer, but the latter tumors orig inate from glandular structures. Epithe liomata arc often caused by irritation, as in the pipe-smoker's epithelioma of the lip and the now almost extinct variety of chimney-sweeper's epithelioma of the scrotum. They are malignant tumors, prone to recurrence, and give metastasis by the lymph-channels, though not to so great an extent as cancer. Their first appearance may be as a wart, fissure, or nodule. Fantastic shapes are often as sumed, as on the penis, when they have I attained considerable size.