(Mr. Annandale's case.)
Belonging to this group also is a form of congenital elephantiasis resulting from the circular constriction of a limb in utero by amniotic bands.
Elephantiasis occurring apart from lymphatic or venous obstruction is illustrated by elephantiasis nervorum, in which there is an overgrowth of the skin and cellular tissue of an extremity in association with neuro-fibromatosis of the cutaneous nerves ([Fig. 89]); and by elephantiasis Græcorum—a form of leprosy in which the skin of the face becomes the seat of tumour-like masses consisting of leprous nodules. It is also illustrated by elephantiasis involving the scrotum as a result of prolonged irritation by the urine in cases in which the penis has been amputated and the urine has infiltrated the scrotal tissues over a period of years.
Sebaceous Cysts.—Atheromatous cysts or wens are formed in relation to the sebaceous glands and hair follicles. They are commonly met with in adults, on the scalp ([Fig. 99]), face, neck, back, and external genitals. Sometimes they are multiple, and they may be met with in several members of the same family. They are smooth, rounded, or discoid cysts, varying in size from a split-pea to a Tangerine orange. In consistence they are firm and elastic, or fluctuating, and are incorporated with the overlying skin, but movable on the deeper structures. The orifice of the partly blocked sebaceous follicle is sometimes visible, and the contents of the cyst can be squeezed through the opening. The wall of the cyst is composed of a connective-tissue capsule lined by stratified squamous epithelium. The contents consist of accumulated epithelial cells, and are at first dry and pearly white in appearance, but as a result of fatty degeneration they break down into a greyish-yellow pultaceous and semi-fluid material having a peculiar stale odour. It is probable that the decomposition of the contents is the result of the presence of bacteria, and that from the surgical point of view they should be regarded as infective. A sebaceous cyst may remain indefinitely without change, or may slowly increase in size, the skin over it becoming stretched and closely adherent to the cyst wall as a result of friction and pressure. The contents may ooze from the orifice of the duct and dry on the skin surface, leading to the formation of a sebaceous horn ([Fig. 100]). As a result of injury the cyst may undergo sudden enlargement from hæmorrhage into its interior.
Recurrent attacks of inflammation frequently occur, especially in wens of the face and scalp. Suppuration may ensue and be followed by cure of the cyst, or an offensive fungating ulcer forms which may be mistaken for epithelioma. True cancerous transformation is rare.
Wens are to be diagnosed from dermoids, from fatty tumours, and from cold abscesses. Dermoids usually appear before adult life, and as they nearly always lie beneath the fascia, the skin is movable over them. A fatty tumour is movable, and is often lobulated. The confusion with a cold abscess is most likely to occur in wens of the neck or back, and it may be impossible without the use of an exploring needle to differentiate between them.
Fig. 99.—Multiple Sebaceous Cysts or Wens; the larger ones are of many years' duration.
Treatment.—The removal of wens is to be recommended while they are small and freely movable, as they are then easily shelled out after incising the overlying skin; sometimes splitting the cyst makes its removal easier. Local anæsthesia is to be preferred. It is important that none of the cyst wall be left behind. In large and adherent wens an ellipse of skin is removed along with the cyst. When inflamed, it may be impossible to dissect out the cyst, and the wall should be destroyed with carbolic acid, the resulting wound being treated by the open method.