Subcutaneous and Submucous Connective Tissue.-Most of the chronic lymphatic affections of the subcutaneous connective tissue are of an infective origin and nature. They are caused by the filaria sanguinis hominis, and they are prevalent in southern countries, where this parasite has its habitat. Reference has been made to a case of almost general lymphangioma of non-infective origin. True lymphangiomatous tumors of the submucous and subcutaneous connective tissue are exceedingly rare (Fig. 322). Steudener described a cavernous lymph

angioma of the conjunctiva. Biesiadecki found a small lymphangioma in the subcutaneous connective tissue. Gjorgewic found a similar tumor, the size of a fist, in the subcutaneous tissue of the thigh in a girl nineteen years old. In this case large quantities of lymph escaped through two small openings. Reichel described a congenital lymphangioma, the size of a pigeon's egg, which he found in the perineum. More comprehensive statistics of lymphangioma can be found in the monographs on this subject by Busey and Wagner.

Uterus. The lymphatic origin of some of the cystic tumors of the uterus has been established by Leopold and Fehling. These cysts contain a fluid which coagulates on exposure to air, and which is often stained by the admixture of blood. The cyst-wall is lined by endothelial cells. Many of these cysts are multilocular, the septa being composed of firm fibrous tissue. The new cysts show in their interior, on silver staining, the characteristic reaction of endothelium. In most instances these cysts occur in connection with myofibromata.

XXV. LYMPHOMA.

UPON histogenetic, histological, and physiological grounds tumors of the lymphatic glands should be excluded from tumors of the true glandular organs. The lymphatic glands are mesoblastic structures, and are not secreting organs. They are hematoplastic organs, physiologically closely allied to the medullary tissue of bone and the spleen. They are composed of lymphoid corpuscles and a delicate reticulum of connective tissue enclosed in a firmer capsule

of connective tissue. They contain normally no epithelial cells (Fig. 323). The lining of the lymphsinuses and the follicles is composed of numerous plate-like connective-tissue cells, in places these elements constituting almost an endothelial covering. The lymphatic vessels and glands are found wherever blood-vessels are present; besides, lymphspaces are found in the cornea. In the submucous tissue lining the different hollow viscera lymphoid tissue is found as a diffuse infiltration in the form of follicles (Fig. 324).

FIG. 323.-Elements of adenoid tissue from partially brushed section of lymphatic

gland of a child (after Piersol): a, fibres of reticulum; 6, lym nective-tissue plate.

phoid cells: c, expanded con

As a lymphatic gland is not a true gland, the tissue composing it is called, from its resemblance to glandular tissue, adenoid tissue; and as it produces the lymph, it is also called lymphoid tissue. Its essential histological element is the lymphoid cell or lymphoid corpuscle, the product of proliferation of the plate-like connective-tissue cell.

Definition.-A lymphoma is a benign tumor formed of lymphatic tissue produced from a matrix of lymphoblasts. In no department of surgical pathology do we meet with more confusion than in the differentiation between benign and malignant tumors and infective swellings of the lymphatic glands. Virchow includes under the term "lymphoma" all tumors and swellings composed of lymphoid tissue. Many authors still continue to speak of a "primary carcinoma" of the lymphatic glands. Some pathologists entirely ignore the existence of non-malignant tumors of the lymphatic glands. This confusion of terms and pathological conditions was increased when Billroth introduced the term "malignant lymphoma." At the present time it is

easier to say what a lymphoma is not than what it is: it constitutes in surgical pathology at the present time a veritable lucus a non lucendo.

Lymphoid tissue is exceedingly susceptible to infection, and is therefore predisposed to acute and chronic inflammation; it is also frequently the seat of sarcoma, but lymphoma, in the restricted sense

The resem

in which this term will be used here, is exceedingly rare. blance in the structure of tumors and infective swellings of lymphatic glands is so close that a reliable differentiation must be based on the clinical aspects and the etiology of the different affections of the lymphatic glands. Enlargement of the lymphatic glands may be due (1) to infection, (2) to sarcoma, (3) to carcinoma, or (4) to lymphoma. The acute affections of the lymphatic glands, characterized by rapid enlargement, pain, tenderness, and fever, are produced by the entrance into the lymphatic system of pyogenic microbes, of the bacillus malleus, or of pre-formed septic material. If the process is chronic, the immediate cause is usually the virus of either syphilis or tuberculosis. In leukemia and pseudo-leukemia the infection is diffuse and is unattended by the usual symptoms which indicate the existence of an acute or a subacute inflammation; the glandular affection either appears diffusely from the beginning or becomes diffuse during its course. These affections point so strongly to the existence of a microbic origin that no doubt can be entertained as to their infective origin. Sarcoma invades successively the glands of the same chain, and frequently terminates fatally by general metastasis. Carcinoma of the lymphatic glands is always a secondary affection; it never occurs as a primary disease, as the lymphatic glands do not contain the essential histological elements-epithelial cells. Lymphoma is a tumor of the lymphatic

congenital. The development of the capsule is very imperfect as compared with true cystomata in the same locality. Arnold divides these tumors into superficial and deep. The former are situated between the skin and the platysma; the latter, beneath the platysma, usually along the anterior surface of the larger vessels. The deep tumors generally reach the greater size. They may surround the whole neck, and may extend beneath and below the clavicle, in the direction of the axillary space. In an upward direction they may encroach upon the cavity of the mouth. Rokitansky and Gurlt believed that these cysts originated in the connective-tissue spaces during intra-uterine life. The formation. of multilocular cysts they explained by assuming that collections of serous fluid formed in different parts of the connective tissue at the same time. It would be impossible to explain why similar hydropic conditions of the connective tissue should not take place in other parts of the body if hydrocele of the neck had such an origin. Luschka maintained that serous cysts of the neck originated in the ganglion caroticum a theory which does not deserve further consideration, since Arnold found this ganglion intact in two cases of hygroma of the neck. The existence of an endothelial lining of the cyst in all cases and the presence of lymphoid tissue in the cyst-wall leave no doubt that in the majority of cases of serous cysts of the neck, of congenital origin, we have to deal with cystic lymphangioma. The serum contained in these cysts is often stained by the admixture of blood, in which event the cysts lose their translucency. If the diagnosis is not clear, an exploratory puncture will provide the desired information. The tumor either remains stationary after birth or increases very rapidly in size. In the former case no treatment is indicated, as a spontaneous cure not infrequently takes place; if this should not be the case, operative treatment is postponed until the child is older. In rapid-growing tumors death often results from pressure of the tumor on the trachea, the œsophagus, and the large vessels and nerves of the neck. In such cases urgent symptoms call for aspiration, which may be repeated as often as the pressure-symptoms demand it. In older children strong enough to withstand the immediate effects of a radical operation, the tumor should be excised, in whole or in part, under strict antiseptic precautions. If complete removal is impracticable, the part of the cyst-wall which remains should be seared with the actual cautery sufficiently deep to destroy its endothelial lining, and the wound should be packed with iodoform gauze. Injections of iodine are too uncertain and dangerous. Injections of carbolic acid after tapping are less objectionable, and should be resorted to if partial or complete excision of the sac is intraindicated.

Subcutaneous and Submucous Connective Tissue.-Most of the chronic lymphatic affections of the subcutaneous connective tissue are of an infective origin and nature. They are caused by the filaria sanguinis hominis, and they are prevalent in southern countries, where this parasite has its habitat. Reference has been made to a case of almost general lymphangioma of non-infective origin. True lymphangiomatous tumors of the submucous and subcutaneous connective tissue are exceedingly rare (Fig. 322). Steudener described a cavernous lymph

angioma of the conjunctiva. Biesiadecki found a small lymphangioma in the subcutaneous connective tissue. Gjorgewic found a similar tumor, the size of a fist, in the subcutaneous tissue of the thigh in a girl nineteen years old. In this case large quantities of lymph escaped through two small openings. Reichel described a congenital lymphangioma, the size of a pigeon's egg, which he found in the perineum. More comprehensive statistics of lymphangioma can be found in the monographs on this subject by Busey and Wagner.

Uterus. The lymphatic origin of some of the cystic tumors of the uterus has been established by Leopold and Fehling. These cysts contain a fluid which coagulates on exposure to air, and which is often stained by the admixture of blood. The cyst-wall is lined by endothelial cells. Many of these cysts are multilocular, the septa being composed of firm fibrous tissue. The new cysts show in their interior, on silver staining, the characteristic reaction of endothelium. In most instances these cysts occur in connection with myofibromata.