Biomedical subjects
Publications and source records attributed to K A Pasyk.
In this article the authors summarize statistical data from 19 patients obtained during quantitative analysis of the thickness of expanded skin and soft tissues utilizing silicone expander procedures. Histopathologic and ultrastructural changes that take place in individual levels of expanded tissues are also illustrated.
Tissue expansion offers a versatile new technique in the reconstruction of many areas of the body. The authors discuss laboratory studies that provide insight into the mechanism of the technique and present examples from clinical experience acquired over the past seven years, including applications in breast reconstruction and reconstruction of the scalp, head and neck, and extremities.
Ultrastructural studies of fibrous capsules surrounding silicone tissue expanders in guinea pigs revealed a number of fibroblasts containing collagen fibers inside cytoplasm with typical periodicity. These fibers were single or multiple, appeared straight, coiled, or bent, and lay in narrow, undulating membrane spaces. These intracellular collagen fibers were found in as many as 15% of the cells in capsules between 7 and 12 weeks of expansion. These observations suggest that during capsule development there is some imbalance between the synthesis of collagen fibers and their degradation. It is possible that increased synthesis of collagen fibers as well as their phagocytosis by fibroblasts may exist simultaneously.
Mast cells were counted in 78 histologic specimens from 70 patients with various vascular malformations showing cellularly dynamic and cellularly adynamic lesions. In growing stages of strawberry hemangiomas, there was an increased number of mast cells (mean 11.0 cells per high-power field in stage III and 23.7 in stage IV), as well as a high number of mast cells in the initial involution of strawberry hemangiomas (stage V, mean 21.0 cells per high-power field). In later involuting stages (stages VI and VII), the number of mast cells decreased (mean 9.3 in stage VI; mean 4.7 in stage VII). In cellularly adynamic lesions, i.e., port wine stains, the mean number of mast cells was 4.8, and in congenital arteriovenous malformations, it was 3.6. In normal skin, the mean number of mast cells was 3.2. In cellular hemangiomas that showed active growth (stages III to IV), the number of mast cells was strikingly low (mean 1.3). It seems that the mast cells are not responsible for the proliferation of the endothelium or for growth of the hemangioma. The markedly increased number of mast cells in the growing stages and initial involuting stage of strawberry hemangiomas parallels the gradual growth of fibrous connective tissue inside the tumor. Mast cells may thus be a precursor of the beginning of the involution of a strawberry hemangioma.
Vascular malformations are described in 25 members of one affected family. Most of these lesions were cavernous hemangiomas, but arteriovenous malformations and capillary hemangiomas were also microscopically observed in some specimens. The five generation pedigree suggests the vascular malformations are genetically determined on the basis of a dominant inherited trait.
Mast cells from 11 patients with growing strawberry (capillary) hemangiomas and cellular hemangiomas and from ten patients with involuting stages of strawberry hemangiomas were investigated electron microscopically. Two types of mast cells were evident: numerous elongated, fibroblastic cells and a few round, classic cells. The mast cells in growing hemangiomas contained many small, simple-type granules in various stages of development. It is possible that, owing to the immaturity of these granules, mast cells have different, probably weaker, functional activities. Mast cells in involuting stages of hemangiomas were filled primarily with compound-type granules, showing typical parallel, concentric lamellae or crystalloid structures, which were similar to the mature mast cells in normal skin.
The fine structure of crystalloid inclusions were found in the endothelial cells of capillary (strawberry) hemangiomas and cellular hemangiomas in nine infants. The inclusions measured from 0.5 to 2.0 microns in diameter and showed parallel lamellar bands with a regular periodicity of about 180 to 300 A. The presence of crystalloid inclusions and the absence of typical rod-shaped tubulated Weibel-Palade bodies suggest the immaturity and embryonic character of the endothelium present in the blood vessels of these kinds of hemangiomas.
Light and electron microscopic studies were conducted on the immature vascular tumors of two infants, containing various stages of differentiation of the blood vessels and both benign haemangioendotheliomas and haemangiopericytomas. We were able to confirm the existence of two kinds of hyperplastic, immature cells i.e. endothelial cells and pericytes in the same tumor. Presence of crystalloid inclusions in the endothelial cells and absence of the Weibel-Palade bodies, as well as a deficiency in factor VIII-related antigen and no tissue fibrinolytic activity, suggested that the endothelial cells in these lesions were immature. Electron microscopic studies appear more decisive in the diagnosis of heterogenous cellular vascular tumors than light microscopy and if available should be used to aid in the final diagnosis. The authors propose that the term cellular haemangioma would be more appropriate in describing this vascular entity.
An electron microscopic study of guinea pig skin and soft tissue after expansion by self-inflating silicone implant for periods of 7 weeks to 8 months revealed definite ultrastructural changes. In the epidermis, the cells of the malpighian layer contained larger groups of tonofilaments forming tonofibrils. Intercellular spaces in all layers of expanded epidermis were much more reduced than in normal epidermis. The basal lamina and the laminar surfaces of the basal cells demonstrated more undulation than those of the controls. The expanded dermis contained large bundles of compacted collagen fibers, as well as thin collagen fibers, active fibroblasts, and a few myofibroblasts. The subcutaneous tissue contained a paucity of adipose tissue and thickened collagen fibers in the interlobular spaces. The skeletal muscle showed larger amounts of sarcoplasm in relation to myofibrils. An increased number and size of mitochondria were found with sarcomeres abnormally arranged. The capsule around the implant was composed of active, elongated, and flattened fibroblasts and bundles of collagen fibers with variable fiber width. Intracellular collagen fibers were found in the cytoplasm of the fibroblasts. Myofibroblasts in the capsule were observed more often in early expanded tissue. Small blood vessels in the capsule showed multiplication of the basal lamina or were surrounded by a very wide, homogenous material. Inflammatory cells were not found in the capsule. Such findings are important in developing and evaluating future skin-expansion research in humans and animals.
To evaluate the histologic changes attendant on tissue expansion in the guinea pig, self-inflating implants were placed in the dorsal subcutaneous space and the tissue response was sequentially studied at periods ranging from 1 to 18 weeks. Fixation artifacts have been minimized. The cellular response is relatively benign. The epidermis does not undergo thinning during expansion, although dermis and panniculus carnosus become significantly thinner. Atrophy of panniculus muscle is demonstrable. This study supports the hypothesis that tissue expansion results in a net gain of donor tissue.
The growth of hemangiomas of the orbital region varies greatly; it is unpredictable. Most lesions never reach sufficient size to impair vision; a few, however, may grow sufficiently to cause disastrous complications. Nine children with complete or partial occlusion of the vision by hemangioma of one eye are reported. (Functional vision was preserved only in those patients who had early subtotal excision of the eyelid hemangioma.) Two children with complete occlusion developed amblyopia in the involved eye. One had optic nerve atrophy. One of the four children with partial occlusion of vision had a permanent decrease in visual acuity. Of the remaining three children with normal vision, two had been operatively treated early, and one had unusually rapid involution of the hemangioma. We recommend that when a child has complete or partial visual occlusion due to hemangioma, subtotal or total excision of the hemangioma should be carried out within 1 week of the onset of visual occlusion to prevent amblyopia.
An unusual case of angiolymphoid hyperplasia with eosinophilia (ALHE) simulating port-wine stain in a 50-year-old woman is reported. The lesions of ALHE are typically papules or subcutaneous masses that range from light pink to red-brown in color. In addition to the usual histologic findings of ALHE, the biopsy in our patient showed some fibrin-like material and fibrous long-spacing collagen on ultrastructural examination. This unusual lesion necessitates biopsy because the differential diagnosis includes port-wine stain, sarcoidosis, lupus erythematosus, and non-Hodgkin lymphoma (mycosis fungoides). Many different forms of treatment have been attempted for ALHE including radiotherapy, cytotoxic chemotherapy, corticosteroids, and antibiotics. The lesions in our patient responded to argon laser therapy and surgical excision, though there has been recurrence on the border of the treated area. Because laser energy is noncumulative in the tissues and effective in removing the lesions, we recommend it as the treatment of choice for these lesions.