Custom Search

 

 

Dermpath-India

Pathology of Lipoma and Variants

Dr Sampurna Roy MD                       2022

 

 

 

Lipoma is a very common subcutaneous which accounts for more than 90% of the adipocytic tumours reported  by the pathologists.

These are usually located on the trunk, proximal limbs, thigh and the neck.

Rare cases have been reported in the vulva.

Usually adults are affected, in the fifth and sixth decades of life.

Clinically, the tumour presents as a well circumscribed, encapsulated slowly growing, soft, mobile tumour.

The tumour varies in size from a few millimeters to 20 cms or more in diameter.

Cut surface mostly reveals mature adipose tissue.

In some cases fibrous or myxoid areas or areas of fat necrosis may be present.

Microscopically, the tumour is composed of mature adipocytes, with minimal variation in size of the adipocytes dissected by thin fibrous septa containing a few blood vessels.  

Fibrolipoma- There is increased stromal fibrosis.

Fibrolipomatous hamartoma of Nerve:

Angiomyxolipoma: The lesion consists of adipose tissue without lipoblasts, extensive myxoid areas, and  numerous blood vessels.

Angiomyxolipoma (vascular myxolipoma) of subcutaneous tissue.

Two cases of angiomyxolipoma (vascular myxolipoma) of subcutaneous tissue.

Adenolipoma:  Adenolipoma of the skin is a superficially located form of lipoma composed of large lobules of mature adipocytic tissue admixed with eccrine ducts and glands.

Cutaneous apocrine cystic adenolipoma.

Adenolipoma of the skin.

Chondroid lipoma:

Chondrolipoangioma:  Prominent chondro osseous and vascular component.

Chondrolipoangioma.A cartilage-containing benign mesenchymoma  of soft tissue.

Myxoid lipoma , myxolipoma: A myxoid background stroma. 

Myelolipoma: Benign, tumor-like lesion consisting of mature adipose tissue with hematopoietic elements arising in the adrenal.

Most are asymptomatic and are discovered accidentally. 

Differential diagnosis : Extramedullary hematopoiesis.

Myelolipoma associated with adrenal ganglioneuroma.  

Angiolipoma:

Intramuscular Lipoma:

Myolipoma: Characterized by adipose tissue together with smooth muscle fibres usually located in the retroperitoneal location and the abdomen.

Differential Diagnosis: angiomyolipoma and liposarcoma with heterologous elements.

Myolipoma of soft tissue.

Myolipoma of the retroperitoneum.

Light and electron microscopic findings in a patient with orbital myolipoma.

Nevus lipomatosus: This lesion presents as plaque or solitary lesions.

Microscopically , mature adipocytes are present in the dermis.

These fat cells are usually not connected with the fat of the underlying subcutis.

Sometimes the adipocytes extend  to undersurface of the epidermis.

There are increased number of ectatic vessels, fibroblasts and mast cells in the  papillary dermis.

Synovial lipoma: (Lipoma Arborescens):

Infiltrating lipoma:  Infiltrating lipoma is an uncommon mesenchymal neoplasm that characteristically infiltrates adjacent tissues and tends to recur after excision. These are usually located  in the thigh, shoulder region, upper arm and in the chest wall. This type of lipoma may rarely occur in the head and neck region.

Lipedematous scalp: There is thickening of the subcutaneous fat of the scalp.

This is usually associated with alopecia.

Hyperplasia of the subcutaneous adipose tissue is the primary histopathologic abnormality in lipedematous scalp.

Lipomatosis: Conditions in which diffuse masses of adipose tissue develop in the subcutaneous tissue.  

-Benign symmetrical lipomatosis

-Familial multiple lipomatosis

-Adiposis dolorosa

-Diffuse lipomatosis

-Pelvic lipomatosis

-Mediastinoabdominal lipomatosis

Cytogenetics:

Rearrangement of 12q, 13q, 6p

 

Further reading:

Lipoma of the oral and maxillofacial region: Site and subclassification of 125 cases.

A rare case of a pedunculated lipoma in the pharynx.

Immunoreactivity for the Human Hematopoietic Progenitor Cell Antigen (CD34) in Lipomatous Tumors.

Size, site and clinical incidence of lipoma. Factors in the differential diagnosis of lipoma and sarcoma.

Giant Infiltrating Lipoma of the Face: CT and MR Imaging Findings

Vulvar lipoma: a case report ;

Large lipoma of the vulva ;

Vulvar lipoma ;

Vulvar lipomas in children: an analysis of 7 cases.

                                                                                                                      

 

 

 

Dr Sampurna Roy  MD

Consultant  Histopathologist (Kolkata - India)

 


Copyright © 2002-2022  histopathology-india.net