An egg in the leg: Case report of an osteochondrolipoma

Lipoblastoma Arising in the Head and Neck: A Clinicopathologic Analysis of 20 Cases

BACKGROUND

Lipoblastomas (LPBs) are benign adipocytic neoplasms believed to recapitulate the development of embryonal fat.

METHODS

We investigated the clinicopathologic and immunohistochemical features of 20 lipoblastomas arising in the head and neck in 18 patients.

RESULTS

Patients included 6 males and 12 females (1:2 ratio) with age at diagnosis ranging from 4 months to 28 years. Tumors occurred more commonly in the neck (12, 66.7%) and less commonly in the forehead, scalp, and tongue (2, 11.1%). Tumor size ranged from 1.4 to 6.0 cm (median 5.0 cm). Two patients, a 4-month-old female and 3-year-old male, had local recurrence of neck tumors at 4 months and 3 years after excision, respectively. Microscopically, tumors had a lobulated growth pattern and consisted of adipocytes at varying stages of differentiation. In addition to the classical histologic features, lipoma-like and myxoid variants constituted 45% of cases. Metaplastic elements, including brown fat and cartilage, were identified in two cases.

CONCLUSIONS

LPBs arising in the head and neck region are not uncommon and occurred at a rate of 9% in our cohort. They should be kept in the differential diagnosis when a fatty tumor is encountered in an older child or occurring at an unusual location.

Case report: Recurrent parosteal lipoma at Dr. Moewardi hospital

Background

Parosteal lipoma is a rare and benign neoplasm originating from mature adipose tissue near the periosteum. Clinically, it is difficult to diagnose due to its similarity to the clinical manifestation of sarcoma, so imaging, histopathology, and immunohistochemistry examinations are necessary.

Case presentation

A 54-year-old woman presented with lump on the right thigh that had gone through surgery eight years prior, with a diameter of 20 cm, with a partly hard and partly soft consistency, the patient was diagnosed with suspected recurrent liposarcoma. We performed wide excision and histopathological results showed a proliferation of bone cells and cartilage cells that were lobulated, surrounded by a proliferation of fat cells with no pleomorphism or immature cells.

Discussion

Parosteal lipomas are neoplasms derived from adult adipose tissue, usually connected to the periosteum, and rare and benign. Two theories of pathogenesis of parosteal lipomas. (1) tumors arise from the differentiation of stem cells derived from adipose tissue, (2) the tumor is derived from secondary metaplasia of fibroblasts due to recurrent trauma, metabolic changes, or ischemia. Based on the theory, it is likely that in this case is due to the presence of differentiation of adiposa tissue due to the non-acquisition of a history of trauma.

Conclusion

Parosteal lipoma is a rare case of benign neoplasm, which is difficult to diagnose clinically due to its similar sarcoma, thus requiring imaging and histopathological examination. The treatment of choice is wide excision by taking the entire tumor to prevent a recurrence.

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45 year old woman with recurrent parosteal lipoma.

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The case of parosteal lipoma is a benign tumor.

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A neoplasm originating from mature adipose tissue, mostly located in the bone cortex below the periosteum.

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The incidence is 0.3% of all types of lipomas and 0.1% of primary bone neoplasms.