Spindle-cell hibernoma: a clinicopathologic comparison of this new variant.

Spindle-cell hibernoma is 1 of 4 histologic variants of hibernomas, which are rare lipomatous tumors distinguished from other lipomas by their brown fat component. This article presents a case of a spindle-cell hibernoma that developed in the groin of a 58-year-old man, and is 1 of only 5 known cases of spindle-cell hibernoma published in the scientific literature. Minimal information is available regarding the clinicopathologic characteristics of the 4 hibernoma variants: typical, lipoma-like, myxoid, and spindle-cell. Spindle-cell hibernoma is believed to be the rarest variant, accounting for approximately 2% of hibernomas. The spindle-cell variant predominantly develops in the fourth and fifth decades, with an average age at diagnosis of 42.5 years (range, 28-59 years). It has a male predilection of 4:1. Previously reported only in the posterior neck and scalp, the groin is now added to the sites of spindle-cell hibernoma occurrence. Our patient's tumor demonstrated low-attenuation on computed tomography and contained moderately-attenuating internal septae. Histologically, in addition to the multivacuolated brown fat component common to all hibernomas, spindle-cell hibernoma has a spindle-cell element without vacuolization that is CD34 positive. No prior treatment details are available on this particular variant. Our patient was treated by marginal excision and was disease free through 13 months of follow-up.

[1]  K. Guven,et al.  CT and MR characteristics of hibernoma: six cases. , 2008, Clinical imaging.

[2]  T. Kubo,et al.  Soft tissue mass of the thigh: presentation , 2007, Skeletal Radiology.

[3]  A. Haims,et al.  Hibernoma: a case report demonstrating usefulness of MR angiography in characterizing the tumor , 2007, Skeletal Radiology.

[4]  S. Espejo-Perez,et al.  Thoracic hibernoma located in costodiaphragmatic recess , 2006 .

[5]  T. Helliwell,et al.  Hibernoma—correlation of histopathology and magnetic-resonance-imaging features in 10 cases , 2006, Skeletal Radiology.

[6]  L. Chirieac,et al.  Characterization of the myxoid variant of hibernoma. , 2006, Annals of diagnostic pathology.

[7]  C. Antonescu,et al.  Hibernoma: report emphasizing large intratumoral vessels and high T1 signal , 2006, Skeletal Radiology.

[8]  H. Hosalkar,et al.  Recurrence and Bleeding in Hibernomas , 2005, Clinical orthopaedics and related research.

[9]  S. Silverman,et al.  Large retroperitoneal hibernoma in an adult male: CT imaging findings with pathologic correlation , 2003, Abdominal Imaging.

[10]  P. Adegboyega,et al.  Hibernoma: a report of 2 unusual cases with a review of the literature. , 2002, Archives of pathology & laboratory medicine.

[11]  J. Reis-Filho,et al.  Lipoma-like hibernoma: an atypical lipoma/well-differentiated liposarcoma mimicker , 2002 .

[12]  C. Schwab,et al.  Hibernoma: imaging characteristics of a rare benign soft tissue tumor , 2001, Skeletal Radiology.

[13]  M. Miettinen,et al.  The Morphologic Spectrum of Hibernoma: A Clinicopathologic Study of 170 Cases , 2001, The American journal of surgical pathology.

[14]  E. Moskovic,et al.  Large retroperitoneal hibernoma -- CT findings with pathological correlation. , 1999, Clinical radiology.

[15]  A. Dessl,et al.  MR imaging findings in hibernoma , 1997, Skeletal Radiology.

[16]  S. Weiner,et al.  Hibernoma of the medial thigh. Case report and literature review. , 1996, Clinical orthopaedics and related research.

[17]  C. Ahn,et al.  Mediastinal hibernoma, a rare tumor. , 1990, The Annals of thoracic surgery.

[18]  C. Cobb,et al.  Cytodiagnosis of hibernoma: A case report , 1987, Diagnostic cytopathology.

[19]  M. Enjoji,et al.  Liposarcoma. A clinicopathologic subtyping of 52 cases. , 1982, Acta pathologica japonica.

[20]  H. T. Enterline,et al.  Does malignant hibernoma exist? , 1979, The American journal of surgical pathology.

[21]  R. McLane,et al.  Axillary hibernoma: review of the literature with report of a case examined angiographically. , 1978, Radiology.

[22]  T. Seemayer,et al.  On the ultrastructure of hibernoma , 1975, Cancer.