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Biomedical subjects

S G Ronan

Publications and source records attributed to S G Ronan.

At least 37 records · Page 2Linked to original sources

Computer diagnosis of skin disease.

A transferable computer program for the differential diagnosis of diseases of the skin, CLINDERM, has been produced for use by physicians on standard IBM and compatible personal microcomputers. This program lists the differential diagnosis and definitive diagnosis of any presented disease of the skin, except single tumors. The physician operator indicates the distribution and detailed description of lesions, which the interactive system integrates with a comprehensive knowledge base. The computer diagnosis in 129 cases was compared with independent interpretation of the same information by an academic dermatologist. Results were synonymous in 66.7% of all diseases and similar in an additional 4.7%. A common differential diagnosis was obtained in 24%, for a 95.3% rate of synonymous, similar, or common differential diagnoses. Diagnosis was different in 3.9% and description was inadequate for diagnosis in 0.8%. The variation in diagnosis showed that some descriptive terms are prejudicial of certain diagnoses; that diagnostic terms are not all completely standardized; that some diagnoses are variants of another disease; and that drug-induced eruptions simulate many other diseases. A skin disease can usually be diagnosed by specific description. Most lesions that are not diagnostic from inspection are nodular. A computer can be programmed to list diagnoses according to morphologic description.

Dermatology↗

Disseminated strongyloidiasis presenting as purpura.

We report a patient with disseminated strongyloidiasis who was being treated with steroids for cerebral edema caused by brain metastases from urinary bladder carcinoma. He had extensive purpura involving the abdomen, arms, and thighs. A skin biopsy specimen showed numerous larvae of Strongyloides stercoralis. Subsequently, rhabdoid larvae of S. stercoralis were isolated in the stool and the sputum. The patient died 2 days later despite thiabendazole therapy.

Diagnosis, Differential↗

Comparative histopathology of porcine and human cutaneous melanoma.

Pigmented tumors resembling cutaneous melanoma were first reported in Sinclair miniature swine in 1967. Since that time, carefully planned breeding has established that this is an inherited malignancy the natural history of which mimics human cutaneous melanoma in a number of ways. Because of these characteristics, miniature swine melanoma appears to be an effective model with which to investigate the mechanisms influencing initiation, growth, and progression of human melanoma. This investigation characterized histologically the cutaneous melanoma in miniature swine and compared the findings with human neoplasm. Primary cutaneous melanoma in swine has been reclassified and standardized according to the classifications currently in vogue in human melanoma. Our results suggest that the condition in miniature swine is histologically similar to that in humans. These observations will provide a basis for interpretation of the results derived in the biologic studies performed in this model.

Animals↗

Growth of Sinclair swine melanoma as a function of age, histopathological staging, and gonadal status.

We have analyzed the association between host hormonal status and growth rate of congenital exophytic melanomas of Sinclair swine. The growth of multiple exophytic lesions during the first year of life of intact males, orchiectomized males, intact females, and ovariectomized females was quantitated using a proliferative index which assigned a numerical value to fixed increments of gains or losses in tumor volume. The proliferative index from 6 wk (gonadectomy at 6 wk) to 52 wk of age of each treatment group was statistically increased from 0 (P less than 0.01) except that of gonadectomized females. The proliferative indices from lesions in gonadectomized females were significantly lower than those from intact males, intact females, and gonadectomized males. A total of 93 exophytic tumors from 63 swine were biopsied and histopathologically staged according to the degree of progression or regression and analyzed as a function of animal age. There were no Stage I and only two Stage II lesions at the time biopsies were taken. Twenty-six of 32 (81.2%) Stage III tumors were found in swine of both sexes less than 26 wk of age of which 71.8% were found less than 10 wk of age, while 20 of 29 (68.9%) were Stage IV, and only 3 of 32 (9%) were Stage V lesions present in this age group (P less than 0.001, chi 2). Only 20.7% of Stage IV tumors were present prior to 6 wk of age. Preliminary results suggest that castration of either sex also altered tumor histopathology. Our data suggest that a reduction in gonadal steroid secretion was associated with a decrease in exophytic tumor growth rate and regression in animals of both sexes during the first year of life in Sinclair swine. The effect in female swine was due to significant reduction in the proliferative index over the first 6 mo of age.

Age Factors↗

Early experimental experience with a surgically created, totally autogenous venous valve: a preliminary report.

A surgically created, totally autogenous venous valve has been devised that holds potential for the treatment of venous insufficiency. Valves were constructed from 2.7 cm long segments of canine external jugular veins. Through the use of intimal separation, folding, and suturing techniques, thin, pliable valves with an intimal lining were constructed and interposed in the canine superficial femoral vein. Fifteen valves were implanted in three groups of dogs. In group I (six dogs) the valves were immediately removed after implantation and subjected to various levels of hydrostatic pressure. In group 2 (six dogs) valves were removed after 1 week and examined for patency and competency. Group 3 animals (three dogs) were anticoagulated with subcutaneously administered heparin from implantation to removal at 7, 9, and 13 days. In group 1 valves were found to open at less than 3 cm of water and remain competent at 55 cm of water. Two of these valves subjected to 300 mm Hg pressure also remained competent. In the six group 2 dogs, two valves remained patent and competent, whereas four valves were patent but incompetent as a result of thrombus that prevented valve closure. In group 3 all valves were patent and competent at 7, 9, and 13 days after implantation. An autogenous venous valve that opens at physiologic pressures and remains competent at high pressures can be surgically created. The ability to remain competent at high pressures may give this valve an advantage over the repaired, transposed, or transplanted native venous valve in the treatment of chronic venous valvular insufficiency.

Animals↗

Cutaneous thick melanoma. Prognosis and treatment.

Among proponents of elective lymph node dissection (ELND) for clinical stage I melanoma, controversy exists as to whether there is an upper limit of tumor thickness beyond which ELND should not be considered. We reviewed 169 patients with clinical stage I and II melanoma that was greater than or equal to 3.0 mm thick and who were treated at the University of Illinois Hospital, Chicago. Of 139 patients with clinical stage I disease, 117 underwent ELND. Five- and ten-year survival rates were 55.7% and 48.9%, respectively. Multifactorial analysis demonstrated that anatomical location, level, pathologic stage, and ulceration were the best predictors of survival. Thickness did not emerge as a significant variable. Our findings do not support basing treatment decisions, eg, ELND in this group of patients, solely on the thickness of the primary tumor. We continue to recommend ELND in patients with either intermediate or thick melanomas.

Adult↗

Computerized dermatopathologic diagnosis.

A practical, transferable microcomputer system for differential diagnosis in dermatopathology, called TEGUMENT, has been developed for use by dermatologists on the standard IBM PC, Compaq, and other compatible personal microcomputers. In an interactive computer program a set of information is abstracted from the microscopic study of each specimen by a dermatologist, to compare with a structured knowledge base. The process leads through a relevant sequence of descriptive phrases until the findings can be allocated to a disease class. The microscopic description and diagnosis are then combined with clinical information by the computer and printed, optionally, as a pathology report. The identification and diagnosis of each case are preserved in permanent memory to enable future search and sorting. The results of independent validation are that a pathologist made the same diagnosis as the machine or a similar differential diagnosis in 91.8%, disagreed in 4.8%, and was unable to make a diagnosis from the description furnished by the machine in 3.4% of 147 actual cases. We conclude that a certain critical minimum of information is required for objective diagnosis; more information is needed for definitive than for differential diagnosis; a characteristic feature is necessary to distinguish between differential diagnoses; an objective description may admit of more than one diagnosis; ambiguity may be reduced by presenting for consideration all distinguishing features that characterize closely related diagnoses; and the personal microcomputer, programmed in this way, is of considerable assistance to the dermatologist in the histopathologic diagnosis of diseases and neoplasms of the skin.

Decision Making, Computer-Assisted↗

Thin malignant melanomas with regression and metastases.

The significance of partial regression in thin malignant melanomas (0.76 mm or less) of the skin was evaluated to determine if the regression was associated with the later development of metastases in patients who previously were considered to have a favorable prognosis. Of 575 patients with primary cutaneous melanoma treated and followed up by the Division of Surgical Oncology at the University of Illinois, Chicago, we found that 103 (18%) had tumors that measured less than 0.76 mm. Of these, 30 (29%) showed histologic evidence of partial regression. In six (20%) of the 30 patients, visceral metastases developed and the patients died. All six had more than 77% regression of their primary tumors. Of the remaining 24 patients, only one had regression greater than 77% and she is still alive three years after diagnosis. Most of these 24 (83%) patients had regression of less than 50% (mean, 29.9%). No metastasis occurred in the 73 patients who had thin melanomas without histologic evidence of regression. It is apparent from this study that patients with thin melanomas who show partial regression cannot be included in the "low-risk" group if the extent of regression is 75% to 80% or more.

Aged↗

The demonstration of papilloma virus in cervical dysplasia and/or neoplasia.

Thirty-three random biopsy specimens of uterine cervix were studied by immunoperoxidase technique to evaluate the presence of HPV antigen in dysplastic and neoplastic cells. Four cases of mild dysplasia, nine cases of moderate to severe dysplasia, two cases of carcinoma in situ and one case of invasive carcinoma were associated with condylomatous lesions. Intranuclear dark-brown precipitates were observed in superficial and intermediate zones of the dysplastic epithelium. Positive reaction was seen in condylomatous epithelium associated with neoplasia. No nuclear precipitates were observed in carcinoma cells, but one noncondylomatous lesion with moderate dysplasia showed positive intranuclear staining. These preliminary findings suggest that papilloma viruses may play a role in the development of human cervical neoplasias.

Condylomata Acuminata↗

Dissecting cellulitis of the scalp.

Dissecting cellulitis of the scalp or perifolliculitis capitis abscedens et suffodiens is a rare, chronic, progressive, suppurative disease of the scalp of unknown etiology. It is characterized by painful nodules, purulent drainage, burrowing interconnecting abscesses, and cicatricial alopecia. The pathogenesis is unknown, although it is probably related to follicular occlusion, secondary infection, and deep inflammation. Black men in their second to fourth decade are predominantly affected. Treatment varies from systemic antibiotics to incision and drainage, x-ray epilation of the affected areas, systemic steroid administration, and surgical excision. Our experience with four patients with extensive scalp disease is presented. Wide excision of the affected areas and splitthickness skin graft are favored as our treatment of choice.

Adult↗

Cutaneous malignant melanoma and bilateral retinoblastomas: a case report and review of the literature.

Retinoblastoma survivors following successful treatment have a predilection to develop other malignant neoplasms. This report describes a patient with bilateral retinoblastomas diagnosed and treated early in life, who developed cutaneous malignant melanoma 20 years later. In our review of the literature only 5 cases with this association have been reported. We would like to report the sixth case.

Adult↗

Panniculitis associated with cutaneous T-cell lymphoma and cytophagocytic histiocytosis.

A 36-year-old woman had a 6-year history of recurrent panniculitis with development of an angiocentric and angiodestructive cutaneous T-cell lymphoma (CTCL) of the helper cell phenotype. She subsequently developed a rapidly progressive fatal syndrome characterized by cytophagocytic histiocytosis and hyperlipidaemia. Cytophagocytic histiocytosis has previously been reported in association with panniculitis, malignancy and infection, but not with CTCL and the precise relationship between panniculitis, CTCL, cytophagocytic histiocytosis and hyperlipidemia is unclear.

Adult↗

Verruciform xanthoma of penis. Light and electron-microscopic study.

A case of verruciform xanthoma of the penis diagnosed by light microscopy was studied ultrastructurally. No extra-oral verruciform xanthoma has been analyzed at the ultrastructural level before. On electron microscopy the lipidized cells were histiocytes distended with lipid vacuoles of varying sizes and electron density. Lipid vacuoles were also in the overlying epidermis. Viral particles were not seen in the epidermal cells.

Adult↗

Benign neonatal eruptive hemangiomatosis in identical twins.

Two cases of neonatal hemangiomatosis occurred in identical twins. Work-up for internal hemangiomas were performed on both infants and were negative. Twin no. 1, with extensive lesions, is currently taking oral prednisone, 2 mg/kg/day, with gradual resolution of the lesions. So far, no new hemangiomas have developed in twin no. 2.

Diseases in Twins↗

Lymphangiosarcoma in chronic lymphedema that followed dissection of the groin in surgical management of a malignant melanoma.

A 41-year-old white man who had a malignant melanoma in the left lumbar area was treated by wide excision and dissection of the ipsilateral inguinal lymph nodes. Progression and irreversible lymphedema of the left lower extremity developed. Fourteen years after the surgery, numerous purplish plaques and nodules developed on the left leg and thigh. Histologic examination by conventional and electron microscopy yielded the diagnosis of angiosarcoma. The patient died 18 months after the diagnosis was made.

Chronic Disease↗

Late recurrence of cutaneous melanoma.

Most patients treated for cutaneous melanoma who have recurrent disease do so within the first ten years after primary diagnosis. This report covers seven patients with clinical stage I disease in whom local or regional recurrence developed 11 to 23 years after first treatment. Six of the seven patients were premenopausal at the time for primary diagnosis, suggesting that gonadal steroids may affect the natural history of cutaneous melanoma by lengthening the disease-free interval. The seventh patient was male. All seven of the patients had regional recurrence that was definitively treated by further surgery. Lymph node metastases occurred in six of these seven patients. After surgical retreatment, all patients lived for at least 2.5 years. Four remain alive, three disease free, and one with partially controlled systemic and regional disease free, and one with partially controlled systemic and regional disease. This study underlines the importance of continued long-term follow-up in patients treated for cutaneous melanoma.

Adult↗