A rare group of tumors occurs due to perivascular epithelioid cells is known as perivascular epithelioid cell tumor (PEComas).  

These tumors present with clear or eosinophilic cytoplasm form and nests or trabecular patterns. The cells express with markers as HMB-45 and melan-A. 

PEComas are found in skin, soft tissues, and internal organs. 

Its co-expresses melanoma and smooth muscle markers with variable staining intensity and distribution. 

The tumors group includes: 

Angiomyolipoma 

Clear cell sugar tumor of the lung 

Lymphangioleiomyomatosis  

Clear cell myomelanocytic tumor  

The two main molecular subgroups are:  

TSC1 / TSC2 alterations 

TFE3 fusions 

Epidemiology is not well-studied due to their infrequent occurrence/nature. Rare PEComas account for a small number of soft tissue and other neoplasm cases. 

PEComas occur at any age, but it is diagnosed more in the age group of 40 to 60 years old and more commonly seen in female patient. 

PEComas can occur in a various of locations as: 

Soft Tissues  

E.g. skin and subcutaneous tissues 

Internal Organs 

E.g. lungs, kidneys, liver 

Site including the gastrointestinal tract 

PEComas originate from perivascular epithelioid cells and mesenchymal cells which are related to blood vessels with unique histological features. 

They are associated with mutations in genes related to the mechanistic target of rapamycin as signaling pathway.  

PEComas range from slow-growing localized tumors to aggressive metastatic forms. They are characterized in the presence of epithelioid cells with eosinophilic cytoplasm.  

The tumors are highly vascularized in nature, which contributes to their growth and as local invasiveness. 

The etiology of perivascular epithelioid cell tumors is not fully known but some causes are: 

Genetic Syndromes with Tuberous Sclerosis Complex 

mTOR Signaling Pathway 

Unknown etiological factors 

Big tumors have higher aggression and metastasis risk with >5 cm tumors have aggressive tendencies. 

Higher cellularity, necrosis, and mitotic activity are directly associated with aggressive tumors and worse prognosis. 

PEComas in genetic syndromes may have different prognoses. 

Metastasized tumors have worse prognosis than localized tumors in general. 

They usually grow slowly, but the clinical behavior may vary significantly.  

Some tumors remain indolent and localized in size and nature, while others can exhibit more aggressive behavior to cause metastasis/local invasion. 

Abdominal Examination  

Pelvic Examination 

Functional Assessment 

Neurological Assessment 

For soft tissue PEComas:  

Palpable masses or lumps 

For organ-specific PEComas:  

Flank pain, hematuria, abdominal pain, liver dysfunction 

Surgical resection is the main treatment for most PEComas to achieve local control and prevent recurrence. 

Radiation therapy is used when surgery is not feasible and for some tumors it is hard to reach due to their location. 

Targeted therapy with mTOR inhibitors is used for advanced or metastatic disease. 

Chemotherapy and radiation therapy may be suggested in severe cases with metastatic or recurrent disease under guidance of surgeons and physicians. 

Oncology, Other

In symptomatic relief phase focus should on pain management, sufficient hydration, nutrition, and proper rest/sleep of patient. 

Some lifestyle modifications including healthy diet, exercise, and stress management should be followed by patients on a regular basis 

Provide behavioural and emotional support to maintain consistency in daily routines and activities. 

Proper awareness about PEComas should be provided and its related causes with management strategies. 

Appointments with a physician and preventing recurrence of disorder is an ongoing life-long effort. 

Oncology, Other

Everolimus: 

It targets on the mTOR signaling pathway, which is involved in cell growth, proliferation, and survival. 

Oncology, Other

Surgical resection is performed for complete removal of the tumor to achieve control and reduce the risk of recurrence. 

Hysterectomy and myomectomy these surgical procedures are indicated as first line treatment therapy. 

Oncology, Other

In the initial assessment phase, evaluation of medical history, biopsy and diagnostic test to confirm diagnosis. 

Pharmacologic therapy is effective in the treatment phase as it includes use of mTOR inhibitors as targeted therapy and surgical intervention. 

In supportive care and management phase, patients should receive required attention such as lifestyle modification and intervention therapies. 

The regular follow-up visits with the physician are scheduled to check the improvement of patients along with treatment response.