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Biomedical subjects

P W Allen

Publications and source records attributed to P W Allen.

18 recordsLinked to original sources
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↗
PubMed1991

Diffuse uterine leiomyomatosis with hemorrhage.

A 28-year-old woman with primary infertility and severe menorrhagia underwent a hysterectomy after failed hormonal therapy for multiple leiomyomas. The postoperative pathologic findings established the diagnosis of diffuse uterine leiomyomatosis, which demonstrated histologic, immunohistochemical, and ultrastructural similarity to leiomyomas of the uterus. The rapid growth of the tumor coincided with the administration of clomiphene citrate, an estrogenic agonist. As with the common leiomyoma, intralesional hemorrhage in this case of diffuse leiomyomatosis was associated with norethindrone acetate treatment given after the cessation of clomiphene therapy.

Adult↗
PubMed1990

Fibrodysplasia ossificans progressiva.

A 14-yr-old boy with fibrodysplasia ossificans progressiva (FOP) presented for surgery for bilateral division of his ossified masseter muscles. Patients with FOP may present problems to the anaesthetist, including difficulties with tracheal intubation, restrictive pulmonary disease and abnormalities of cardiac conduction. With our patient sedated the trachea was intubated using a fibrescope and anaesthesia was induced and maintained with nitrous oxide and enflurane in oxygen. Ventilation was controlled throughout surgery and recovery was uneventful.

Adolescent↗
PubMed1989

Desmoplastic malignant melanoma and its variants. A study of 45 cases.

Forty-five tumors exhibiting the histological features of desmoplastic malignant melanoma or its variant, neurotropic melanoma, were found among approximately 4,500 soft-tissue tumors referred in consultation from Australia and New Zealand. All patients were Caucasians. Tumors fell into three groups: (a) desmoplastic melanoma with an atypical intra-epidermal melanocytic component (classical desmoplastic melanoma) (12 cases); (b) desmoplastic melanoma without an atypical intra-epidermal melanocytic component (de novo desmoplastic melanoma) (21 cases); (c) predominantly nerve-centered superficial malignant tumors with or without an atypical intra-epidermal melanocytic component (12 cases). Three of the nerve-centered tumors were associated with pigmentary abnormalities in the overlying skin. The patients' ages ranged from 42 to 91 years, with a peak in the seventh decade; 31 patients were male and 14 were female. Lesions were located in the head and neck (35 cases), shoulder and arm (four), back and chest (three), abdomen (one), thigh (one), and leg (one). Three tumors arose in irradiated areas, and one occurred on the face of a radiotherapist. Melanin was found in only four tumors, but the S-100 protein stain was positive in 19 tumors and negative in three. Follow-up details of 42 patients were available. In follow-up times from 4 months to 15 years (mean, 4.6 years), 15 patients (36%) had died of the disease or were terminally ill; 24 (57%) were alive with no apparent residual tumor; and three (7%) had died of other causes. Twenty-three patients (55%) developed one or more local recurrences; 17 (40%) developed distant spread, including extension into the cranial cavity along nerves; and 14 (33%) had both local recurrence and distal spread. Nine (82%) of 11 patients with nerve-centered tumors died or were terminally ill. The usual treatment was surgical. Most uncontrolled recurrences were resistant to chemotherapy and radiotherapy; however, two patients responded well, one to chemotherapy and one to radiotherapy. Our observation support Reed and Leonard's metaplastic explanation for the varied differentiation seen in desmoplastic melanomas.

Adult↗
PubMed1977

Ewing's sarcoma.

Explore the source record for details and available documents.

Adolescent↗
PubMed1975

Inverted urinary papilloma: report of five cases and review of the literature.

Five new cases of inverted urinary papilloma are described and 13 previously reported cased are reviewed. All 18 examples were seen in adult males, with ages ranging from 26 to 79 years (average 57 years). Ten patients presented with symptoms of bladder outlet obstruction and 8 with haematuria. With one probable exception all of the tumours were solitary. Sixteen were found in the region of the bladder neck and prostatic urethra, and only 2 occurred on other sites. The papillomas were pedunculated or sessile and ranged in size from a few mms to 3 cms in greatest diameter. Most had smooth surfaces in contrast to the usual exophytic papillary urothelial neoplasms. Microscopically they showed a striking resemblance to the inverted papillomas of the nasal cavity and paranasal sinuses. In those examples where the stalk or base of the papilloma was included in the sections, there was no evidence of invasion of the underlying smooth muscle. Fourteen of the patients have been followed for periods ranging from 7 months to 11 years (average 2.5 years) and no recurrences have been documented. Simple local resection, by the transurethral route where possible, appears to be adequate treatment for these distinctive papillomas.

Aged↗