Ossifying parosteal lipoma of the thoracic spine: a case report and review of literature

Parosteal lipoma of rib causing widening of intercostal space in an adolescent

Parosteal lipomas are typically seen in adults and affect mostly the diaphysis of the long bones of the upper and lower limbs. Only a few cases have been reported in children until now and none were reported involving ribs. A female adolescent patient presented with swelling on the left upper back over the scapular region for the past 4 years without any neurological deficit. MRI revealed a hyperintense lesion on the left paravertebral region extending from D5 to D12 and into the intercostal space, causing it to widen. The patient underwent surgical excision. The lipomatous mass was seen entering in to the intercostal space, causing it to widen. However, the pleura was not breached. In this report, we have performed a literature review compiling all cases of parosteal lipoma affecting the ribs.

Multimodality imaging features of parosteal lipomas

OBJECTIVE

To examine the multimodality imaging characteristics of parosteal lipomas.

MATERIALS AND METHODS

With IRB approval, our institutional imaging database and medical record were retrospectively reviewed from 1990-2020 for cases of pathologically-proven and/or imaging diagnosed parosteal lipomas.

RESULTS

There were 22 patients (12 males, 10 females) with a mean age of 57.1 ± 12.7 years (range 31-80 years). 11/22 cases (50%) were pathologically-confirmed on biopsy or surgical resection and 11/22 (50%) had imaging features compatible with parosteal lipoma. Lesions occurred most commonly along the femur (8/22, 36%), followed by the forearm (3/22, 14%). All cases demonstrated a juxtacortical fatty mass containing an osseous excrescence that was firmly attached to the cortical surface. The osseous excrescences were characterized as pedunculated in 16/22 (73%) and sessile in 6/22 (27%). The average largest dimension of the osseus excrescences was 2.4 ± 1.6 cm (range 0.8-6.1 cm) and the lipomatous portions 7.8 ± 3.8 cm (range 2.0-19.5 cm). The excrescences contained mature bone in 12/22 (55%) cases and a mixture of mature bone and radiating bone spicules in 10/22 (45%). There were non-lipomatous elements in the fatty portion of the mass in 13/22 (59%) of cases. Most cases (19/22, 85%) had cortical thickening/periostitis near the base of the osseous stalk. Two patients had a bone scan that demonstrated uptake in the osseous excrescence, and two patients had an FDG PET/CT that demonstrated no uptake.

CONCLUSION

Parosteal lipomas are a rare benign lipomatous tumor with pathognomonic multimodality imaging features that may obviate the need for biopsy.

Parosteal lipoma of the radius with posterior interosseous nerve palsy

Parosteal lipoma is a rare benign soft tissue mesenchymal tumour that may impair limb motor function when located adjacent to neurovascular structures. We report a case of a woman in her 80s with a long-standing lesion in the forearm and consequent sensory and motor function changes. She was admitted for an elective excision of the lipoma. Postoperative evolution was favourable, with marked improvement of limb function. Our aim in sharing this case is to create awareness of these rare deep-seated lipomas that might originate nerve palsy and should therefore be excised as soon as possible to avoid neurological damage.

Lipomatous Tumors in Pediatric Patients: A Retrospective Analysis of 50 cases

OBJECTIVE

Although lipomatous tumors are the most common type of mesenchymal tumors in adults, they account for less than 10% of all soft tissue lesions in pediatric patients. In this descriptive study, we aim to present our series of pediatric lipomatous tumors consisting of lipoma, neural fibrolipoma, lipoblastoma, atypical lipomatous tumor, myxoid liposarcoma and pleomorphic liposarcoma, and to evaluate the clinicopathological characteristics of these tumors in reference to the literature.

MATERIAL AND METHOD

In this study, pediatric lipomatous tumor cases diagnosed between 2002 and 2018 were screened from pathological archives and retrospectively evaluated.

RESULTS

A total of 50 cases were diagnosed with lipomatous tumor within the mentioned period. Of the total cases, 24 were female (48%) and 26 were male (52%), with age distribution ranging from 1 to 204 months. Histopathological examination revealed lipoma in 26 cases (52%), lipoblastoma in 19 (38%), atypical lipomatous tumor in 2 (4%), myxoid liposarcoma in 2 (4%), and pleomorphic liposarcoma in 1 case (2%).

CONCLUSION

Although lipomatous tumors are the most common type of mesenchymal tumors; they rarely occur in children. Since there is a limited number of studies on pediatric lipomatous tumors in the literature, there is insufficient data on the prevalence and incidence of these tumors. These tumors may slowly enlarge to greater sizes, especially those localized in deep tissues, and may cause various clinical symptoms by compressing surrounding tissues. Local recurrences may occur, even after total excision, and require close monitoring.

Parosteal Lipoma of Proximal Radius: A Case Report of an Unusual Swelling and Review of Literature

INTRODUCTION

Lipomas are considered to be benign tumors comprising 50% of all soft tissue tumors. They originate from mesodermal germ layer but are classified based on component tissue and location. Parosteal lipomas are frequently located at the extremities, particularly at diaphysis or diametaphysis of long bones.

CASE REPORT

Here, we report a case of parosteal lipoma with a delayed presentation involving dominant right forearm without any neurological deficits to create awareness of the rare existence of this benign tumor.

CONCLUSION

A prompt diagnosis of such tumors has to be done as early as possible.

[Parosteal osseous lipoma of the temporal bone concurrent with involvement of the parotid salivary gland]

The paper describes a case of parosteal lipoma of the temporal bone, by simultaneously involving the parotid salivary gland. Computed tomography performed in a 48-year-old man showed that in the area of the posterior edge of the glenoid fossa of the right temporal bone there was a massive (1.5×1.7×0.9-cm) exostosis extending down from the skull base. The exostosis was surrounded by a 3.5×3.6×5.3 soft tissue mass that was located in the projection of the right parotid salivary gland with a capsule and minor calcifications. Morphological examination determined a sessile exostosis-like mass in the area of the periosteum of the temporal bone. Foci of desmal and enchondral ossification (types III and IV according to the classification of Miller et al.) could be seen in the adjacent fatty tissue. The tumor underwent necrotic and dystrophic changes (Milgram's Stage 3). Temporal bone involvement was accompanied by osseous sialolipoma of the right parotid salivary gland. In this case, the fatty component accounted for 60-80% of salivary gland volume. Terminal secretory segments, ducts, and bone trabeculae with calcification foci and hematopoietic elements were uniformly distributed among the fatty tissue. None similar case has been found in the literature.