E. B. Chung

Benign lipoblastomatosis. An analysis of 35 cases

The pathologic features and the behavior of 35 cases of lipoblastomatosis, a benign tumor frequently confused with a liposarcoma, were presented. In the reviewed material, the tumor affected exclusively infants and young children, with 88% of the cases occurring before the age of 3 years. It involved most commonly the soft tissues of the lower and upper extremities. A circumscribed and a diffuse form of lipoblastomatosis could be distinguished. The circumscribed form was the mose common one (23 of 35 cases); usually it was superficially located and clinically comparable to a lipoma. The diffuse form was more deeply situated and was analogous to a diffuse lipomatosis. Nine cases belonged in this category. In three cases, the data were insufficient to classify them as to the circumscribed or diffuse type. Microscopically, both forms showed an identical histologic picture consisting of tabulated immature adipose tissue composed of lipoblasts, a plexiform capillary pattern, and a richly myxoid stroma. Although the term “lipoblastomatosis” has been used in the past for both circumscribed and diffuse forms, it is suggested that the term “benign lipoblastoma” be employed for the circumscribed type and the term “benign lipoblastomatosis” for the diffuse type of this tumor. Follow‐up information revealed a benign clinical course with a low rate of recurrence (14%), probably attributable to incomplete removal of the tumor; three of the five recurrent tumors were of the diffuse type. Complete local excision appears to be the treatment of choice.

Multiple bile‐duct hamartomas

Six cases of multiple bile‐duct hamartomas are reported as incidental findings in 875 autopsies (0.69%). All of the patients were Negroes; there were 3 males and 3 females, ranging in age from 46 to 93 years. One patient had associated bilateral congenital polycystic kidney and hemangiomas of the liver. Another patient had associated unilateral congenital cysts of the kidney and a cortical hamartoma of the ipsilateral kidney. Gross and microscopic variations of bile‐duct hamartomas are illustrated and their significance is discussed. To avoid possible oversight of the lesions, reexamination of the liver after fixation in 10% neutral formalin is recommended. It is also emphasized that the histology of the lesions may be clear‐cut hamartomas or may suggest neoplastic growths. The relationship of bile‐duct hamartomas to polycystic disease of the liver is discussed. Its association with congenital hepatic fibrosis and congenital dilatation of the intrahepatic bile ducts is presented.