Letter to the editor. Re: Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma. Report of a case

Re: Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma. Report of a case

Dear Editor, Recently, we read with great interest an article by Laliotis et al. named “Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma: Report of a case” published in the Polish Journal of Pathology [1]. Although the case is very interesting and unique, we would like to make a few comments regarding the description of this case.
First, no MRI of the ordinary lipoma was included in the description of the case; therefore its imaging anatomical relationship with the spindle cell lipoma was not demonstrated. The authors state that on MRI a well-defined intramuscular lesion located within the medial part of the right latissimus dorsi muscle was identified. Subsequently, a CT scan showed the same mass under the latissimus dorsi, which contradicts the MRI report. This description poses two questions: Is the spindle cell lipoma intramuscular or intermuscular? And second, is it possible that heterogeneous histological findings in the same mass led to the assumption that there were actually two separate masses? The latissimus dorsi and rhomboideus muscles are in a close anatomical relationship and it is very possible that an intermuscular mass under the medial part of the latissimus dorsi may expand over the rhomboid muscle.
Second, no detailed histological description of the lipoma was provided; therefore it is not clear if that tumor was of infiltrative (usually more commonly found) or well-circumscribed (less common) type.
Third, the co-existence of spindle cell lipoma and an ordinary lipoma has been documented [2-5]. The authors state that the concurrent intramuscular existence of spindle cell lipoma and of an ordinary lipoma is very rare. However, of all the cases the authors referenced (Table I), in only one case was the ordinary lipoma located intramuscularly with the spindle cell lipoma located inside the ordinary lipoma. The rest of the cases are subcutaneous separate masses. That leaves the case by Laliotis et al. as the first case described of concurrent intramuscular spindle cell lipoma and intramuscular ordinary lipoma in the same patient.
Fourth, no cytogenetic testing was performed. Cytogenetic testing has been shown to be very useful for the diagnosis and prognosis of lipogenic tumors. Sometimes histology alone may not be sufficient to provide the correct diagnosis. Furthermore, cytogenetic testing may be useful for the prognosis as tumors with complex cytogenetic aberrations have a propensity to be more aggressive locally. This patient did not have long-term follow-up. Intramuscular lipomas and low-grade lipomatous lesions sometimes recur many years after the initial excision.
In conclusion, we believe that it is very possible that the two masses presented in this case in fact represent a single mass with heterogeneous histological findings which grew intermuscularly with eventual secondary muscular invasion. Furthermore, cytogenetic testing should be included as an integral part of lipomatous masses work up, especially in difficult and unusual cases. An interesting note is that all of the reported cases concerned men.

The authors declare no conflict of interest.

References

1. Laliotis A, De Bree E, Vasilaki S, et al. Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma: report of a case. Pol J Pathol 2013; 64: 224-227.
2. Sakai H, Kuroda K, Hara D, et al. Coexistence of spindle cell lipoma and ordinary lipoma. J Dermatol 2004; 31: 831-834.
3. Usta U, Türkmen E, Mizrak B, et al. Spindle cell lipoma in an intramuscular lipoma. Pathol Int 2004; 54: 734-739.
4. Siddiqui MA, Su L, Michael CW, et al. Synchronous ordinary lipoma and spindle-cell lipoma diagnosed by fine needle aspiration. Diagn Cytopathol 2006; 34: 455-456.
5. Turhan-Haktanir N, Demir Y, Ayçiçek A, et al. Concurrent large spindle cell and ordinary lipomas. J Craniofac Surg 2007; 18: 1193-1195.

Ivan Chernev MD
Clinical Assistant Professor of Physical Medicine
and Rehabilitation
West Virginia School of Osteopathic Medicine,
Lewisburg, WV, USA
Attending Physician in Physical Medicine
and Rehabilitation
Department of Medicine,
Appalachian Regional Healthcare, Beckley,
WV, USA

Shane Mctighe OMS III
Medical Student
West Virginia School of Osteopathic Medicine,
Lewisburg, WV, USA

Dirk P. Stanley MD
Attending Physician in Anatomic and
Clinical Pathology
Department of Medicine,
Appalachian Regional Healthcare, Beckley,
WV, USA
Address for correspondence

Ivan Chernev MD
ARH Southern WV Clinic
250 Stanford Road, Beckley, WV, 25801, USA
Office Phone: 304-254-2646, 304-254-2650
fax: 304-254-2794
e-mail: ivantchernev@yahoo.com