Adipocytic tumours
Adipocytic tumours fall into the grouping soft tissue lesions and includes things that are very common (e.g. lipoma) and everything from benign to malignant.
Overview
This grouping includes a number of tumours, which can be divided based on their behaviour into benign, intermediate and malignant.
Benign
Benign adipocytic tumours:[1]
- Lipoma.
- Angiolipoma.
- Myolipoma.
- Pleomorphic lipoma/spindle cell lipoma.
- Lipomatosis.
- Lipomatosis of nerve.
- Lipoblastoma.
- Extrarenal angiomyolipoma.
- Extra-adrenal myelolipoma.
- Hibernoma.
Intermediate
Intermediate adipocytic tumours:[1]
- Atypical lipomatous tumour.
Malignant
Malignant adipocytic tumours:[1]
- Dedifferentiated liposarcoma.
- Myxoid liposarcoma.
- Pleomorphic liposarcoma.
- Mixed-type liposarcoma.
- Liposarcoma NOS.
Detail section
Normal mature fat
Microscopic
Features:
- Adipocytes of approximately equal size.
- Not vascular.
- No nuclear hyperchromasia.
Notes:
- May have nuclear pseudoinclusions (Lockhern cell).[2]
- There is some suggestion this is not benign.[3]
IHC
- S-100 +ve.
Lipoblastoma
General
- Rare paediatric tumour.[4]
Usual presentation:[4]
- Painless neck mass.
Microscopic
Features:
- Nests of cells in the dermis with abundant pale cytoplasm - vaguely resemble adipocytes.
- Smaller than mature adipocytes.
DDx:
Images:
Lipoma
Main article: Lipoma
Pleomorphic lipoma
General
Gross
- Classically shoulder and neck region in adults.[8]
DDx - shoulder lesions:
Microscopic
Features:
- Multinucleated cells - "floret cells" - key feature.
- Solid eosinophilic cytoplasm.
- Peripheral nuclei - impart a knobby border to the cells.
- Fibrous septa.
Notes:
- May overlap with spindle cell lipoma.[9]
- Floret cell - may look similar to Touton giant cells.
Images:
- Pleomorphic lipoma - low mag. (webpathology.com).
- Pleomorphic lipoma - high mag. (webpathology.com).
DDx:
- Liposarcoma.[10]
- Ancient neurofibroma.
- Ancient schwannoma.
IHC
- AR +ve - ~95% in men, ~85% in women.[7]
- CD34 +ve (26 +ve of 26 cases[11]).
- Desmin -ve (0 +ve of 20 cases[11]).
- ER -ve/+ve (5 +ve of 21 cases[11]).
Spindle cell lipoma
Main article: Spindle cell lipoma
Hibernoma
Main article: Hibernoma
Atypical lipomatous tumour
General
- Atypical lipomatous tumour is a term used to save people with a (curable) peripheral liposarcoma from getting denied life insurance.
Microscopic
Features:[13]
- Large adipocytes.
- Atypical lipoblasts - focal, scattered:
- Nuclear hyperchromasia.
- +/-Multinucleated.
Liposarcoma
Main article: Liposarcoma
See also
References
- ↑ 1.0 1.1 1.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 601. ISBN 978-0781765275.
- ↑ URL: http://journals.lww.com/amjdermatopathology/Citation/2004/12000/Original_Observation_to_Rediscovery__Nuclear.9.aspx. Accessed on: 18 April 2011.
- ↑ URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970574-5. Accessed on: 18 April 2011.
- ↑ 4.0 4.1 Pham, NS.; Poirier, B.; Fuller, SC.; Dublin, AB.; Tollefson, TT. (Jul 2010). "Pediatric lipoblastoma in the head and neck: a systematic review of 48 reported cases.". Int J Pediatr Otorhinolaryngol 74 (7): 723-8. doi:10.1016/j.ijporl.2010.04.010. PMID 20472310.
- ↑ Nagano, A.; Ohno, T.; Nishimoto, Y.; Hirose, Y.; Miyake, S.; Shimizu, K. (2011). "Lipoblastoma mimicking myxoid liposarcoma: a clinical report and literature review.". Tohoku J Exp Med 223 (1): 75-8. PMID 21212605.
- ↑ Persichetti, P.; Di Lella, F.; Marangi, GF.; Cagli, B.; Simone, P.; Tenna, S.; Rabitri, C.; Cassandro, R. et al. "Pleomorphic lipoma: a definite histopathological entity.". Anticancer Res 24 (5B): 3157-9. PMID 15510605.
- ↑ 7.0 7.1 Syed, S.; Martin, AM.; Haupt, H.; Podolski, V.; Brooks, JJ. (Jan 2008). "Frequent detection of androgen receptors in spindle cell lipomas: an explanation for this lesion's male predominance?". Arch Pathol Lab Med 132 (1): 81-3. doi:10.1043/1543-2165(2008)132[81:FDOARI]2.0.CO;2. PMID 18181679.
- ↑ URL: http://www.webpathology.com/image.asp?n=2&Case=435. Accessed on: 3 October 2011.
- ↑ URL: http://surgpathcriteria.stanford.edu/softfat/spindle_cell_lipoma/. Accessed on: 4 December 2010.
- ↑ Azzopardi, JG.; Iocco, J.; Salm, R. (Jul 1983). "Pleomorphic lipoma: a tumour simulating liposarcoma.". Histopathology 7 (4): 511-23. PMID 6884998.
- ↑ 11.0 11.1 11.2 Cheah, A.; Billings, S.; Goldblum, J.; Hornick, J.; Uddin, N.; Rubin, B. (Feb 2015). "Spindle cell/pleomorphic lipomas of the face: an under-recognized diagnosis.". Histopathology 66 (3): 430-7. doi:10.1111/his.12548. PMID 25219904.
- ↑ Creytens, D.; van Gorp, J.; Savola, S.; Ferdinande, L.; Mentzel, T.; Libbrecht, L. (Jul 2014). "Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma.". Virchows Arch 465 (1): 97-108. doi:10.1007/s00428-014-1568-8. PMID 24659226.
- ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 605. ISBN 978-0781765275.