Pieter J. Slootweg

Juvenile ossifying fibroma: report of four cases

The present investigation concerns 4 patients with juvenile ossifying fibroma (JOF) whose data are analyzed together with 30 cases from the literature. The tumour mainly occurs in juveniles, 79% of the patients being 15 years or younger. Radiologically as well as at surgery, the lesion is demarcated from its surroundings. Histologically, JOF is unique in showing a loose-fibroblastic stroma that contains garland-like strands of osteoid with entrapped osteoblasts, the latter feature not being observed in other fibro-osseous lesions. JOF responds very well to conservative treatment that provided permanent cure in all cases with adequate follow-up data.

The status of the resection margin as a prognostic factor in the treatment of head and neck carcinoma

The value of the status of the resection margin as a prognostic factor after surgical treatment was investigated in 80 patients with squamous cell carcinoma of the oral cavity, oropharynx and laryngohypopharynx. The relation of locoregional recurrence with the presence or absence of tumour at the surgical margin was analysed together with other indications for postoperative radiotherapy. Locoregional recurrence was observed in 20% and was correlated with tumour thickness over 5 mm, spidery growth and tumour-positive margins. Tumour-positive margin as a single indication for postoperative irradiation was not related to an increased recurrence rate. When however occurring together with other indications for postoperative irradiation, the recurrence rate was higher than in the patient group with the same number of indications for postoperative radiotherapy but without tumour at the surgical margins.

Mandibular invasion by oral squamous cell carcinoma

Summary Forty-five specimens consisting of mandibular bone and adjacent squamous cell carcinoma were histologically investigated. In 23 of them, there was no involvement of the mandibular bone: a continuous periosteal layer separated the tumour from the bone. Tumour spread through periosteal lymphatics was not observed in any of these cases and therefore there is no reason to sacrifice bone when the tumour is not fixed to the jaw. Twenty-two specimens exhibited bony involvement. In 10 of them, the bone was eroded by an advancing tumour front. None of these cases exhibited tumour invasion into cancellous spaces, dental canal or periodontal ligament space. Tumours with this type of bony involvement are amenable to mandible-sparing surgical treatment. The other 12 exhibited diffuse growth into cancellous bone, dental canal and, if present, periodontal ligament space. Cases like these are to be operated on by removing the entire thickness of the involved mandibular part. Tumours involving bone were slightly larger than those leaving bone uninvolved. The tumours eroding bone were of a smaller size than those infiltrating bone. The differences, however, are too small to have a predictive value in treatment planning. Attention is drawn to the presence of dental epithelial rests that should not be mistaken for invading tumour nests.

Treatment failure and margin status in head and neck cancer. A critical view on the potential value of molecular pathology

Molecular pathology may demonstrate tumour cells not detected by histology. The idea has emerged that these cells influence the prognosis negatively and that their detection will lead to more appropriate treatment and improved patient survival. We theorized that tumour cells at surgical margins overlooked by the pathologist should demonstrate their clinical significance by causing recurrences at the primary site in the patients reported to have tumour-free margins by histology. To assess this assumption, we investigated the prognostic influence of the histologically determined status of the surgical margins. The material that formed the basis of this study consisted of 394 patients that underwent resection for their primary tumour during the years 1990-1995. In 207 patients, initial treatment was complete as assessed by conventional histopathological examination of the surgical specimen. In 187 patients, initial treatment was incomplete, defined as tumour in or close to the margin, or mild, moderate or severe dysplasia or in situ cancer at the margin. Causes for treatment failure were recorded for both groups separately. In the group with tumour-free margins, 16.9% had a second primary head and neck cancer, 8.2% had a second tumour in the lung, 10.6% had recurrent disease in the neck, 2.9% had distant metastasis, and 3.9% had local recurrence at the same site as the primary cancer. For the group without tumour-free margins, these figures were the following: second primary in the head and neck area: 17.1%, second primary in the lung: 7.0%, recurrent disease in the neck: 11.8%, distant metastasis: 8.0% and local recurrence at the primary site: 21.9%. Local recurrences were rare in patients in which the pathologist reported the resection to be complete. Although there may be tumour cells in surgical margins that evade histological detection, their clinical impact appears to be almost negligible.

Myxoma of the jaws: An analysis of 15 cases

A retrospective study on 15 patients with myxomas of the jaws was carried out. The series consisted of 3 males and 12 females. The mean age was 26 years. The maxilla was involved in 4 cases whereas the tumour was situated in the mandible in 11 cases. Of the 9 patients who underwent conservative treatment, one exhibited recurrent tumour. Six patients were treated by resection including uninvolved adjacent tissue; none of them has so far exhibited recurrence. These results indicate that carefully performed conservative treatment for myxomas is justified in some instances. Histologically, myxomas of the jaw exhibit mitotic activity in the majority of cases which indicates a distinct proliferative activity. Myxomatous degeneration in neurofibromas may mimic myxoma. Therefore the present cases were compared with 2 cases of intramandibular neurofibroma. It is concluded that differences in nuclear morphology are sufficient to distinguish between both neoplasms.

The origins of multiple squamous cell carcinomas in the aerodigestive tract

Chemoprevention and cessation of smoking and alcohol may prevent development of multiple tumors (MTs) in the aerodigestive tract if new MTs arise independently, but they are of no benefit if MTs are due to migration of an already transformed clone of tumor cells. This issue was addressed in this study by investigation of the clonality among MTs.

Condylar hyperplasia. A clinico-pathological analysis of 22 cases

A series of 22 cases of unilateral condylar hyperplasia is presented with the emphasis on histopathological aspects. It is concluded that there are two types of condylar hyperplasia. The first manifests itself in the adolescent or the young adult and represents an exaggerated, normally proceeding growth and maturation process. The histological structure of the condyle in these cases is age-dependent as is shown by a conversion of hyaline growth cartilage into fibrocartilage occurring at about 20 years of age. The second type of condylar hyperplasia, seen in older people, probably represents reactive growth as a response to an eliciting agent that mostly can be identified. In these cases the histological architecture of the condyle is distorted by large masses of hyaline cartilage while there are concomitant degenerative changes in the form of arthrosis. In contrast to the patients suffering from the first type of condylar hyperplasia, the latter ones complain of additional joint symptoms, mostly pain. Moreover it is concluded that joint scintigraphy does not clearly discriminate between genuine condylar hyperplasia and reactive processes due to arthrosis, which may have clinical implications.

p16INK4A overexpression is frequently detected in tumour‐free tonsil tissue without association with HPV

Klingenberg B, Hafkamp H C, Haesevoets A, Manni J J, Slootweg P J, Weissenborn S J, Klussmann J P & Speel E‐J M
(2010) Histopathology 56, 957–967
p16INK4Aoverexpression is frequently detected in tumour‐free tonsil tissue without association with HPV

Differential diagnosis of fibro-osseous jaw lesions. A histological investigation on 30 cases.

A series of 30 fibro-osseous jaw lesions was evaluated for histological parameters that enable appropriate diagnostic classification. Special emphasis was laid upon the histomorphology of the lesion-jawbone interface, blending of lesional bone with adjacent jawbone being employed as the decisive factor in distinguishing between fibrous dysplasia and other fibro-osseous jaw lesions. Using this feature as a discriminative tool, other histological aspects that were useful in differential diagnosis could be identified. Fibrous dysplasia (n = 11) shows a rather uniform appearance with a constant ratio bone: fibrous tissue throughout the entire lesion; acellular mineralized particles are virtually absent. Juvenile ossifying fibroma (n = 3) is characterized by a highly cellular fibroblastic stroma and garland-like strands of cellular osteoid. Ossifying fibroma (n = 12) shows a high variability in stromal cellularity and types of mineralized material. Localized periapical fibro-osseous cemental lesions (n = 4) are histologically almost similar to ossifying fibroma although more heavily mineralized. It is concluded that there is full agreement between histology and radiology in indicating whether a fibro-osseous jaw lesion is demarcated or blends into its surroundings. Moreover, an appropriate diagnosis can be reliably made on histological grounds.

EWSR1 gene rearrangement occurs in a subset of cutaneous myoepithelial tumors: a study of 18 cases

Cutaneous myoepithelial tumors form a clinicopathological spectrum ranging from mixed tumor to myoepithelioma and myoepithelial carcinoma. Recently, EWSR1 rearrangement has been described in a subset of soft tissue myoepithelial tumors, whereas the cutaneous counterparts showed this aberration in a minority of cases. This raises the question whether cutaneous myoepithelial tumors have comparable genetic alterations. We examined 18 cases of cutaneous myoepithelial tumors arising in 7 female and 11 male patients (age range, 34–86 years; mean, 58 years). Eight mixed tumors occurred at the head, and one at the scrotum. Six myoepitheliomas arose at the extremities, and one case each at the back and head. One myoepithelial carcinoma occurred at the cheek. The tumor size ranged from 0.3 to 1.7 cm (mean, 1.0 cm). All mixed tumors and three myoepitheliomas were limited to the dermis. Four myoepitheliomas and the myoepithelial carcinoma involved the subcutis. Mixed tumors and myoepitheliomas were composed of myoepithelial cells with a variable cytomorphology, architecture and stromal background. Ductal structures were seen by definition in mixed tumors. The myoepithelial carcinoma represented an infiltrative dermal neoplasm consisting of atypical spindle cells. Immunohistochemically, all cases tested were positive for EMA and calponin, whereas S100, CK, ASMA and GFAP were expressed in 90%, 80%, 78% and 50% of the cases tested, respectively. By fluorescent in situ hybridization analysis, 7 out of 16 cases (44%) exhibited EWSR1 rearrangement. Four of them were mixed tumors, two were myoepitheliomas and one was a myoepithelial carcinoma, confirming that these lesions represent a spectrum of dermal myoepithelial tumors. Follow-up information, available for five patients (including the patient with a myoepithelial carcinoma), revealed no evidence of disease in all cases (range, 6–72 months). Our study provides a genetic relationship of myoepithelial tumors of the skin with their counterparts in soft tissue, bone and visceral localization by sharing EWSR1 rearrangement.