Pigmented villonodular synovitis of thoracic facet joint presenting as rapidly progressive paraplegia.

Pigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovial membrane of uncertain etiology. It commonly affects synovial joints of the appendicular skeleton and rarely affects the spine. We present the case of a young man presenting with a rapidly progressive myelopathy due to spinal cord compression by PVNS arising from a thoracic facet joint, which finally resulted in paraplegia.The spinal location of PVNS has been seldom emphasized in the rheumatologic literature. PVNS should be considered as a possible cause of soft tissue masses arising from the facet joints, with variable degrees of nerve root or spinal cord compression.

Malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1: report of two clinical cases.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a sarcoma with a high grade of malignancy originating in the nerve sheath components, fibroblasts, perineural cells, and Schwann cells. It is associated with neurofibromatosis type 1 (NF-1) with a risk of 10-13%. CLINICAL CASES: We present two cases of NF-1-associated MPNST. The first patient presented moderate pain with no apparent cause, in addition to the presence of intraspinal lesion demonstrated by nuclear magnetic resonance imaging (NMRI), which was managed surgically on two occasions. Histologically, it corresponded to a neurofibromatosis lesion in transition with malignant neoplasm. The second case manifested with thoracic kyphoscoliosis, pain, and an increase in volume. Associated with the deformity, MRI showed a withering tumor in the posterior thoracic region (T1-T8), observing an infiltrating, cellular sarcomatous neoplasm with immunopositivity for S-100 protein and vimentin. CONCLUSIONS: MPNSTs are sarcomas with a high index of recurrence with the ability to produce distant metastasis during early stages. Despite wide resection, patients did not survive due to the advancement and size of the lesions (determining factors in the prognosis). Due to the progressive growth of MPNST and the anatomic difficulty for its approach, there should be strict surveillance of patients with NF-1 for early detection of malignant transformation in these lesions.

[Primary intradural extramedullary tumors treated at the National Institute of Rehabilitation (Mexico)]. / Tumores intradurales extramedulares primarios tratados en el Instituto Nacional de Rehabilitación.

BACKGROUND: Spine tumors are uncommon injuries affecting a low percentage of the population; however, these tumors can cause significant morbidity and may be related to mortality. They represent 15% of craniospinal tumors. The objective of this study is to determine the frequency of intradural extramedullary spine tumors treated in our Service and to report the definitive histopathological diagnosis. METHODS: This was a retrospective study in a series of patients treated surgically with a diagnosis of intradural extramedullary tumor in the Spine Service of the National Rehabilitation Institute (Mexico) from 1996 to 2006. The following variables were evaluated: gender, age, tumor localization, symptomatology and type of tumor. RESULTS: Files of 27 patients were reviewed. There were 11 men and 16 women with an average age of 47.33 years. The main symptoms were pain and motor weakness. The most frequent localization was thoracic followed by lumbar. Histopathological diagnosis reported 12 cases of meningioma, 12 cases of schwannoma and 3 cases of neurofibroma. CONCLUSIONS: Symptomatology, localization and gender predominance are similar to that reported in the literature. Different from other series, schwannomas and meningiomas were the most frequent tumors in our study. Appropriate diagnosis and opportune treatment consisting of total resection with laminoplasty are crucial in order to avoid permanent neurological consequences.

Fibrous hamartoma of infancy. Case report.

BACKGROUND: Fibrous hamartoma of infancy (FHI) is an infrequent benign proliferation of the soft tissues. Ninety one percent of cases occur during the first year of life. FHI is characterized as a subcutaneous lesion with characteristic morphology with a triphasic organoid growth pattern. CLINICAL CASE: We present the case of a 6-month-old male infant with a tumor in the medial plantar region of the left foot, which was completely withered. Histopathological study reported a fibrous hamartoma of infancy. CONCLUSIONS: Fibrous hamartoma of infancy most frequently affects males. It may be localized at any anatomic site, although 5-10% of cases affect the lower limbs. Few cases are reported in the foot. This is a lesion with a characteristic morphological pattern; however, in small biopsies, its differential diagnosis is important with other fibroadipose lesions for appropriate treatment. Ample surgical resection with lesion-free borders confers a good prognosis for these patients.