Innocuous Lesions Research Articles

Acetabular pneumatocyst containing air-fluid level

The presence of intraosseous gas most commonly occurs in osteomyelitis, vacuum phenomenon, and postsurgery or posttraumatic states. Several cases of subchondral gas-filled lesions, called pneumatocysts, have also been described in the sacroiliac joint and clavicle, none of them with intralesional air-fluid level. These pneumatocysts are innocuous lesions of uncertain origin. We describe one case of acetabular pneumatocyst containing air-fluid level in a 62-year-old man with long-standing ankylosing spondylitis involving hip joint. To our knowledge, this is the first reported case of a pneumatocyst in an acetabular location containing air-fluid level.

Measurement of magnetization transfer in different stages of neurocysticercosis.

The purpose of this study was to establish magnetization transfer ratio (MTR) in different stages of neurocysticercosis. A total 2,532 cysticerci were studied prospectively in 15 cases. MTR from different regions of the lesions (ie, the cyst, the protoscolex or mural nodule, the granuloma wall) were calculated in different stages of evolution/degeneration in all cases. Of a total 2,532 lesions studied, 2,261 (89.29%) were seen on routine spin-echo (SE) imaging. The rest of the lesions were only seen on magnetization transfer (MT) SE imaging. Maximum MTR was calculated from healing lesions (mean + SD = 31.0+/-2.8) and from the core of SE invisible lesions (30.0+/-5.1). Innocuous cystic lesions, which were hyperintense on T2-weighted images, did not show any MT (MTR = 5.10+/-1.2), whereas degenerating T2 hyperintense lesions showed MTR of 26.40+/-2.7. Nondegenerating and degenerating scolices showed an intermediate MTR of 21.7+/-3.3 and 15.0+/-4.5, respectively. MT varies between different parts of the lesion and also from the same part in different stages of evolution/degeneration of the lesion. The visibility of a lesion on MT-SE sequence was dependent on its MTR and its location at a particular site (cortical gray matter, white matter, or deep gray matter). The difference in MTR of the lesion and the surrounding brain parenchyma decides the resulting contrast and visibility of the lesion.

Immunohistochemical assessment of tumor vascularity in recurrent Clark II melanomas using antibody to type IV collagen

Thin melanomas, measuring 0.76 mm or less, are generally associated with an excellent prognosis. However, a certain subset of these seemingly innocuous lesions have been reported to develop recurrences. Therefore, the predictive values of currently accepted prognostic indicators have been questioned in thin melanomas. Several studies concerning tumor vascularity in melanoma and certain non-melanocytic malignancies suggest that the degree of vascularization correlates with growth rate and biologic aggressiveness. In the present study, we determined the vascularity of a small group of Clark level II melanomas that resulted in recurrence, and compared these results to an equal number of nonrecurrent lesions with similar prognostic indicators. Blood vessels were labeled by immunoperoxidase staining techniques for Type IV collagen, and quantified by image analysis. No statistical difference was found between the two groups when mean blood vessel counts and percent vascular area were measured. The recurrent tumors had a mean PVA of 4.68 compared to 4.34 for the nonrecurrent group (p = 0.677). The mean blood vessel count beneath the recurrent group was 29.6 per 400 x field, and the corresponding value for the nonrecurrent group was 31.8 (p = 0.681). Our data is preliminary within this limited group of tumors, yet it suggests that tumor vascularity is not a distinctive prognostic indicator by which eventual outcome can be predicted in thin Clark level II malignant melanomas.

Extra-Abdominal Desmoid Fibromatosis

Desmoid fibromatosis cannot be considered a biologically benign or innocuous lesion. In the head and neck it may be intraosseous (desmoplastic fibroma) or, more often, in soft tissues, with the highest incidence in the supraclavicular region of the neck. High recurrence and persistence rates, 50% or more, accompany intralesional or marginal excision. Keloids and proliferative scars, while stubborn in their resolution and potentially disfiguring, are reactive proliferative disorders of fibroblastic and myofibroblastic tissues.

Clinical features of alcoholic liver disease

The severity and range of histological liver lesions caused by alcohol abuse varies considerably; these lesions are not specific for alcoholic damage, and diagnosis of alcoholic liver disease depends on obtaining an adequate history of prolonged alcohol abuse and on excluding other known causes of liver disease. The clinical features of alcoholic liver disease vary greatly and they have been classified into various syndromes. However, the syndromes overlap, the histological features underlying them also overlap and they represent part of a wide clinical spectrum. Alcoholic fatty liver occurs more in younger patients and has a much better prognosis than alcoholic hepatitis or alcoholic cirrhosis, but the previous view that alcoholic fatty liver is an innocuous lesion can no longer be maintained. Alcoholic hepatitis and alcoholic cirrhosis cause more severe syndromes and more florid clinical features, and mortality is related to features of liver failure and variceal bleeding. Abstinence is the only means of ensuring the best possible survival.

Histopathologic Study of Recurrent Clark Level II Melanomas

Overall, the prognosis for thin lesions of melanoma (less than 0.76 mm) is excellent. However, a number of melanoma patients with seemingly innocuous lesions have been reported to develop recurrences. For this reason, we examined histologic sections taken from eight cases of Clark level II melanoma that unexpectedly recurred, and compared their histopathologic features with an equal number of nonrecurrent lesions in whom reliable clinical follow-up data were available. Prognostic variables including Breslow thickness, mitotic rate, ulceration, the presence or absence of regression, a vertical growth phase component, and an associated banal nevus were evaluated in a double blind manner. When attempts were made to predict outcome based on one or more prognostic variables, the only correlation of statistical significance was the Breslow thickness (P = 0.04). A Breslow thickness greater than 0.4 mm was associated with a significantly shorter disease free interval than a thickness below 0.4 mm. There was no significant correlation between predicted outcome based on the histologic features examined and the eventual outcome based on history of recurrence (P = 0.36). These data indicate that although prognostic models that predict outcome in melanoma are generally reliable, there is a sizable population of patients with thin melanomas that do worse than would be expected.

Superficial Mucoceles of the Oral Mucosa

Superficial mucoceles are innocuous vesicular lesions that have been mistaken for mucous membrane pemphigoid. Clinically they are asymptomatic, small, clear, tense vesicles that have a predilection for the retromolar pad area, posterior buccal mucosa, and soft palate. Microscopically they are subepithelial extravasations of sialomucin that occur at the epithelial connective tissue interface. Minor salivary gland ducts are present in the immediate vicinity of the lesions and are a clue to the correct diagnosis. Demonstration of sialomucin is diagnostic.

Granular cell tumour of the larynx

A granular cell tumour may present as clinically innocuous lesions on the vocal cords and the diagnosis is usually made by histopathology. However, the granular cells characteristic of this tumour may not be obvious and accompanying epithelial hyperplasia may be interpreted by the pathologist as invasive squamous cell carcinoma. Good communication between pathologist and surgeon is required to ensure that clinically benign lesions on the vocal cords are not misdiagnosed. The diagnosis of granular cell tumour can be confirmed by immunocytochemical staining for S100 antigen.

Xanthomatous lesions of the mandible: Osseous expression of non-X histiocytosis and benign fibrous histiocytoma

Seven cases of xanthomatous lesions of the manidble, followed from 1 to 18 years, are documented. All lesions were benign and painless; radiographic appearances varied from single and well-demarcated to diffuse and multilocular. Microscopic examination showed sheets of histiocytes with xanthoma or foam cells, fibroblasts and fibrous tissue, and inflammatory cells as well as cells in transition, with characteristics of both histiocytes and fibroblasts. Immunohistochemical staining and electron microscopic observation provided further evidence of the biphasic nature of this cell population. Twelve similar cases were found in the literature under a variety of diagnostic or descriptive labels. Our findings show that these lesions are histiocytic in nature and that they range from small, innocuous lesions, which we regard as the osseous counterpart of non-X histiocytosis, to larger, more destructive lesions diagnosed as benign fibrous histiocytoma (fibrous xanthoma) of bone.

Geographic stomatitis: review of the literature and report of five cases

Five new cases of geographic stomatitis have been presented along with data from 24 previously reported patients. For the first time, basic parameters of this disorder have been tabulated from this population. Although the earliest documented case appeared in the literature in 1955, the majority of articles has been published during the last 15 years. This increased frequency of reporting indicates a growing awareness of this rather innocuous lesion. Thus, the general practitioner is advised to become familiar with the salient features of geographic stomatitis. Prompt recognition and diagnosis of this lesion, based on the clinical findings and history, will usually mitigate the need for biopsy.

How well do physicians recognize melanoma and other problem lesions?

The alarming increase in the incidence of cutaneous malignant melanoma in the United States emphasizes the importance of its early detection and treatment. Early detection requires accurate clinical recognition of both malignant and precancerous skin lesions (dysplastic nevi). This study presents data on dermatologists' and nondermatologists' ability to diagnose skin lesions. A total of 105 nondermatologist physicians, from first-year residents to practicing physicians, and forty-eight dermatologists were asked to identify color slides or photographs of eleven cutaneous lesions, including malignant melanomas, dysplastic nevi, and innocuous lesions such as seborrheic keratoses and common moles. Diagnosis of cutaneous lesions was generally inaccurate among nondermatologists. Only 38% correctly identified four or more of the six melanomas as melanoma of any type, and 58% were unable to diagnose dysplastic nevi. Only 17% categorized their relevant training as excellent or good. Improved training in the diagnosis of skin lesions for practicing physicians and house staff is required if mortality from malignant melanoma is to be decreased in the United States.