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Biomedical subjects

P W Allen

Publications and source records attributed to P W Allen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Increased awareness of glove perforation in major joint replacement. A prospective, randomised study of Regent Biogel Reveal gloves.

An intact barrier between the hands of the surgeon and the patient remains the single most important factor in protection against infection for both. Increasing the awareness of possible glove perforation without skin penetration will decrease the risk of contamination. We performed a prospective, randomised trial comparing the incidence of glove perforation using a new type of glove (Regent Biogel Reveal) and standard double-gloves in total hip and knee replacement. One or more perforations was detected in 14.6% of all gloves. The new gloves increased significantly the awareness of perforation. Multiple perforations at the base of the ring finger were found in surgeons who wore wedding rings during the operation and we recommend that rings be removed before undertaking surgery.

Chi-Square Distribution↗
PubMed1996

The Iowa CHMIS (Community Health Management Information System): work in progress.

The Iowa Community Health Management Information System (CHMIS) is a legislatively authorized system that is designed to meet Iowa's shared information needs and reduce administrative costs. A public/private partnership has been planning this system for over three years, implementation is scheduled to begin in July 1996. At that time, certified transaction networks will route claims data between providers and payors, a subset of that data will be stored by a centralized data repository. As the system evolves, provider access will be expanded and additional data elements will be captured.

Community Networks↗
PubMed1996

[Angiomatoid malignant fibrous histiocytoma].

By clinical, pathologic and immunohistochemical study on aniomatoid malignant fibrous histiocytoma, which is a relatively uncommon soft tissue tumor described by Enzinger in 1979, and often misdiagnosed, we are reporting 32 cases of this lesion. The distinctive histopathology were: (1) Cystic change filled with hemorrhagic fluid or blood, (2) surrounded by nests of fibroblastlike and histocyte-like cells and (3) intermingled with chronic inflammatory cells, (4) often surrounded by a fibrous pseudocapsule. Immunohistochemical staining done in 4 cases showed all to be positive in lysozyme, three positive in Mac 387 and CD 68. These results support their histiocytic origin. Follow-up information was available in 25 of 32 cases. All the 25 patients were alive, 4 with recurrence (16%), 1 with metastasis (4%). These results concur with the opinion that intrinsically, this is a low grade tumor.

Adolescent↗
PubMed1995

Aggressive fibromatosis of the spermatic cord. A typical lesion in a "new" location.

The authors describe a 31-year-old man with a 7 cm aggressive fibromatosis (desmoid tumor) of the spermatic cord presenting as a swelling in the left inguinal area that was excised along with the testis and cord. The desmoid tumor is histologically typical, but such tumors arising primarily from the paratesticular structures have apparently not been previously reported and the diagnosis would not be questioned if it not for the unusual site. This tumor is histologically and immunohistochemically indistinguishable from abdominal wall desmoid tumor, with or without Gardner's syndrome. Desmoid tumors at this location should be distinguished from reactive processes, such as pseudosarcomatous myofibroblastic proliferation (so-called "proliferative funiculitis") and inflammatory fibrous pseudotumor, all of which exhibit fibroblastic/myofibroblastic differentiation. Paratesticular fibrosarcoma and leiomyosarcoma should also be differentiated from desmoid tumor that does not have the metastatic potential of sarcomas. Thirty-four months post-operatively, an 8 cm local recurrence in the remaining portion of the left vas deferens causing left hydroureter and hydronephrosis was detected.

Adult↗
PubMed1995

Nuchal fibroma. A clinicopathological study of nine cases.

Nuchal fibroma apparently was first described in the second edition of Enzinger's and Weiss's text book in 1988. We have been unable to find any other accounts of this entity. We have reviewed the clinicopathological features of nine nuchal fibromas, eight of which were referred in consultation. Eight patients were men; the ages ranged from 19 to 53 years (median, 43). Patients were first seen with solitary, unencapsulated, subcutaneous swellings in the back of the neck or dorsal region measuring from 2.5 to 8 cm in maximum dimensions (median, 3.5). Macroscopically, lesions were firm, fibrofatty masses. Histologically, there were sheets of hypocellular dense collagen with interspersed mature fat, inconspicuous, small, thin-walled vessels, and entrapped nerve fibers. The picture suggested a fibrolipoma, a lipomatosis, scar tissue, or even elastofibroma, but the small amount of elastic tissue present lacked the beaded, nodular appearance of elastofibroma. Follow-up information was available in seven cases. In follow-up times from 6 months to 19 years (median, 6 years), one tumor was reexcised 4 months after an incisional biopsy and had not recurred 19 months later. None of the others recurred. The lack of a capsule, the entrapment of nerves, and the predilection for the nuchal or dorsal regions suggest that this hypocellular, benign, fibrofatty lesion is a distinct entity and not merely a lipoma.

Adipose Tissue↗
PubMed1994

Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor.

Malignant transformation of a schwannoma (neurilemoma) is an exceedingly rare event. We describe two cases with such change and review the reported purported examples. The tumors in our patients involved a finger and pelvis. Sex, age, and clinical follow-up were available for only the second case, involving a 31-year-old man who died with recurrent and metastatic tumor. Seven acceptable cases were found in the literature. Analysis of the nine cases of schwannoma with malignant transformation showed no sex predilection, but revealed a tumor differing significantly from conventional malignant peripheral nerve sheath tumors. The mean age (56 years) was two decades older, no patient had neurofibromatosis, in four cases there was a years-long history of an antecedent mass, and in none of the cases was the malignant component an interlacing, fasciculated spindle-cell tumor. Rather, the malignant component was commonly purely epithelioid (seven of nine cases). In the two other cases, cells of the malignant component had neuroepithelial features. The prognosis for patients with schwannomas undergoing malignant change is poor. Five of eight patients with follow-up (62%) died of disease with either residual (one patient) or metastatic tumor (four patients).

Adult↗
PubMed1994

Perce the permissive pathologist: a cautionary tale of one who misdiagnosed a pseudosarcoma, killed the patient and was found out.

Perce, a promising young trainee pathologist, correctly recognizes a biopsy of a benign pseudosarcoma but his diagnosis is overruled by the less well read Head of Pathology. Acting under instructions from his Chief, Perce knowingly and without protest 'signs out' this benign condition as a sarcoma. The surgeon accepts the diagnosis without question and performs radical surgery, which is complicated by postoperative haemorrhage from which the patient dies. The Coroner orders a review of the slides and the misdiagnosis is discovered. Perce's defense that he did as he was told is rejected; he is forced to quit pathology and becomes an administrator. This unfortunate tale, which is related in verse, is intended to stress the importance of such benign but uncommon pseudosarcomas as nodular fasciitis, proliferative myositis, myositis ossificans, postoperative spindle cell nodule, pseudosarcoma of the bladder and juxta-articular myxoma. The poem also implies that surgeons should not carry out radical surgery based on an uncommon pathological diagnosis without checking on the adequacy of consultation and informed review of the sections.

Diagnostic Errors↗
PubMed1994

Tufted angioma with complete regression.

We describe 2 patients with tufted angioma (angioblastoma of Nakagawa) which regressed spontaneously. Both patients had a solitary but large lesion on the trunk. The 1st patient, a 3-month-old girl, presented with a 6-cm plaque which began to regress 2 years later. It regressed completely over 1 year and had not recurred after a further 6-year follow-up. The other patient, a 3-month-old boy, presented with a 12-cm mass of coalescent angiomatous papules which slowly regressed over 3-years, while small new lesions appeared in the adjacent contiguous skin. Eventually, gradual and near complete regression was observed after 8 years. The histology in both cases was typical, but bore some resemblance to the recently described kaposiform hemangioendothelioma, lobular capillary hemangioma and spindle cell hemangioendothelioma.

Female↗
PubMed1993

Arthroscopic treatment of cysts of the lateral meniscus.

We have treated 69 patients with 72 cystic lateral menisci by arthroscopic surgery. Meniscal tears were observed in all cases, and 69 of these had a horizontal cleavage component. Three types of tear were identified and may be progressive. Treatment was by arthroscopic resection of the meniscal tear, and decompression of the cyst through the substance of the meniscus. After a mean follow-up of 34 months the results were good or excellent in 64 knees (89%) and there were few complications. We recommend this technique as the treatment of choice for cysts of the lateral meniscus.

Adolescent↗
PubMed1992

The histiocytoid hemangiomas and other controversies.

We have reviewed the clinicopathologic features of Kimura's disease, angiolymphoid hyperplasia with eosinophilia, epithelioid hemangioma of the testis, epithelioid hemangioendothelioma, spindle cell hemangioendothelioma, malignant endovascular papillary angioendothelioma of childhood (Dabska's tumor), epithelioid angiosarcoma, angioblastoma of Nakagawa, bacillary angiomatosis, verruga peruana, and other inflammatory angiomatoses. On the basis of our experience and reading of the literature, we conclude that angiolymphoid hyperplasia with eosinophilia, histiocytoid hemangioma of the testis, epithelioid hemangioendothelioma, and probably spindle cell hemangioendothelioma, constitute a group of related conditions best called the histiocytoid hemangiomas. Kimura's disease, Dabska's angioendothelioma, epithelioid angiosarcoma, and the inflammatory angiomatoses are not histiocytoid hemangiomas. Angioblastoma of Nakagawa is not related to lobular capillary hemangioma (pyogenic granuloma).

Adolescent↗
PubMed1991

Locally metastasizing vascular tumor. Spindle cell, epithelioid, or unclassified hemangioendothelioma?

The authors report the case of a 2-year-old boy with a recurrent and locally metastasizing, spindle cell, vascular tumor with histiocytoid cells involving the skin, subcutaneous tissue, and muscle of the right forearm, the right distal radius and ulna, and multiple lymph nodes of the right axilla. Diagnoses of hemangioma, hemangiopericytoma, angiomatosis, spindle cell hemangioendothelioma, and malignant hemangioendothelioma were made on successive excision specimens. The soft tissue of the right arm became diffusely enlarged, and a severe syndrome developed that was similar to that described by Kasabach and Merritt. The limb was amputated above the elbow, the axillary lymph nodes were cleared, and a total dose of 6,000 centigrays axillary radiation was given. After operation, the Kasabach-Merritt syndrome resolved. Despite the lymph node metastases and multiple tissues involved, the patient has remained well 6 years after surgery. Although the tumor exhibited some of the histologic features of a spindle cell hemangioendothelioma, the low-grade aggressive behavior resembled that of an epithelioid hemangioendothelioma. The reported case cannot be classified into any of the recognized categories or subdivisions of vascular tumors.

Bone Neoplasms↗
PubMed1991

Spinal cord monitoring in scoliosis surgery. Experience with 1168 cases.

Since 1981, during operations for spinal deformity, we have routinely used electrophysiological monitoring of the spinal cord by the epidural measurement of somatosensory evoked potentials (SEPs) in response to stimulation of the posterior tibial nerve. We present the results in 1168 consecutive cases. Decreases in SEP amplitude of more than 50% occurred in 119 patients, of whom 32 had clinically detectable neurological changes postoperatively. In 35 cases the SEP amplitude was rapidly restored, either spontaneously or by repositioning of the recording electrode; they had no postoperative neurological changes. One patient had delayed onset of postoperative symptoms referrable to nerve root lesions without evidence of spinal cord involvement, but there were no false negative cases of intra-operative spinal cord damage. In 52 patients persistent, significant, SEP changes were noted without clinically detectable neurological sequelae. None of the many cases which showed falls in SEP amplitude of less than 50% experienced neurological problems. Neuromuscular scoliosis, the use of sublaminar wires, the magnitude of SEP decrement, and a limited or absent intra-operative recovery of SEP amplitude were identified as factors which increased the risk of postoperative neurological deficit.

Adolescent↗