Desmoid type fibromatosis in the facet joint of lumbar spine: case report and review of literature

Primary extradural tumors of the spinal column: A comprehensive treatment guide for the spine surgeon based on the 5th Edition of the World Health Organization bone and soft-tissue tumor classification

BACKGROUND

In 2020, the World Health Organization (WHO) published the 5th version of the soft tissue and bone tumor classification. Based on this novel classification system, we reviewed the current knowledge on all tumor entities with spinal manifestations, their biologic behavior, and most importantly the appropriate treatment options as well as surgical approaches.

METHODS

All tumor entities were extracted from the WHO Soft-Tissue and Bone Tumor Classification (5th Edition). PubMed and Google Scholar were searched for the published cases of spinal tumor manifestations for each entity, and the following characteristics were extracted: Growth pattern, ability to metastasize, peak age, incidence, treatment, type of surgical resection indicated, recurrence rate, risk factors, 5-year survival rate, key molecular or genetic alterations, and possible associated tumor syndromes. Surgical treatment strategies as well as nonsurgical treatment recommendations are presented based on the biologic behavior of each lesion.

RESULTS

Out of 163 primary tumor entities of bone and soft tissue, 92 lesions have been reported along the spinal axis. Of these 92 entities, 54 have the potential to metastasize. The peak age ranges from conatal lesions to 72 years. For each tumor entity, we present recommended surgical treatment strategies based on the ability to locally destruct tissue, to grow, recur after resection, undergo malignant transformation as well as survival rates. In addition, potential systemic treatment recommendations for each tumor entity are outlined.

CONCLUSION

Based on the 5th Edition of the WHO bone and soft tumor classification, we identified 92 out of 163 tumor entities, which potentially can have spinal manifestations. Exact preoperative tissue diagnosis and interdisciplinary case discussions are crucial. Surgical resection is indicated in a significant subset of patients and has to be tailored to the specific biologic behavior of the targeted tumor entity based on the considerations outlined in detail in this article.

Value of imaging findings in predicting post-operative recurrence of desmoid-type fibromatosis

Desmoid-type fibromatosis is a rare type of soft-tissue tumor originating from connective tissue of the fascia or aponeurosis, which exhibits aggressive growth, high likelihood of relapse and less frequent distant metastasis. The present study aimed to predict the recurrence rate and time by retrospectively analyzing the clinical data (sex, age and recurrence time), imaging findings [tumor location, maximum diameter, border, computed tomography (CT) enhancement ratio, magnetic resonance enhancement ratio and T2 signal ratio] and pathological features (Ki-67 and microscopic margin) in a total of 102 cases of pathologically confirmed desmoid-type fibromatosis. The risk ratio of each factor was calculated using the Cox proportional hazards regression model and the cumulative recurrence-free survival rate was determined using the Kaplan-Meier method and the log-rank test. The cohort comprised of 73 females and 29 males, with mean age of 32.86±12.64 years (range, 6–78 years). The 1-year and 2-year recurrence rate was 31 and 54%, respectively. The median age at recurrence was 29 years. Univariate analysis indicated that sex, maximum tumor diameter, CT enhancement ratio and Ki-67 had a significant effect on the recurrence time. Furthermore, multivariate analysis revealed that sex, maximum tumor diameter, Ki-67 and T2 signal ratio were independently associated with the time of recurrence, and the risk ratios were 0.424, 1.100, 1.084 and 1.268, respectively. Therefore, in male patients with a larger maximum tumor diameter, positivity for Ki-67 and a higher T2 signal ratio, desmoid-type fibromatosis was more likely to recur after surgery.

Desmoid tumors in neurosurgery: a review of the literature

Desmoid tumors (DTs) are rare myofibroblastic neoplasms, which are mostly sporadic, but sometimes associated with familial adenomatous polyposis syndrome. Neurosurgical cases of DT have been very scarce. We review the literature concerning neurosurgical DTs and describe the first case of a cicatricial DT after the resection of vestibular schwannoma, presenting as a painful swelling in the retrosigmoid scar. Contrary to other localizations in the body, standard-of-care wide margin resection cannot be performed in intracranial and spinal DTs. Therefore, maximally safe resection followed by radiotherapy when tumor margins are not free can be proposed as a treatment strategy in neurosurgical DTs.