Myospherulosis

Abstract

Myospherulosis is a rare tumor caused by interaction of extravasated erythrocytes and exogenous or endogenous lipids. Fifty-nine articles presented 181 patients with myospherulosis since first description in 1969. Myospherulosis seems to occur in any age and in any part of the body; however, most frequent sites are paranasal sinus and subcutaneous tissue. In most cases, exogenous lipids from postoperative packing are damaging the erythrocytes, but also spontaneous cases are described. Diagnosis is made by histology but can be already suggested by radiographic imaging. Differential diagnoses include infections by fungi or algae due to histopathologic similarity. Besides that, radiographic imaging and morphology can wrongly be interpreted as carcinomas, metastases, osteofibrosis, or echinococcosis. Myospherulosis is a benign process, with symptoms deriving from the space occupying character and surgical excision can bring cure. We discuss the clinical presentation, diagnosis, and treatment and provide a systematic review of the literature on myospherulosis.

Endobronchial ultrasound-guided Transbronchial needle aspiration (EBUS-TBNA) in simulator lesions of pulmonary pathology: a case report of pulmonary Myospherulosis

“…The term myospherulosis was coined in 1969 by McClatchie after a case series report of 7 African patients who developed histological changes at the injection site posterior to receiving intramuscular (IM) penicillin injections ( myo comes from muscle tissue) [ 1 ]; they consisted in the formation of cystic spaces surrounded by an intense inflammatory reaction rich in lymphocytes, histiocytes, plasmocytes and giant cells, similar to that observed in foreign bodies reactions [ 1 , 2 ]. Later on, the term collagenous spherulosis was adopted to describe a series of benign lesions of similar characteristics found in breast pathology, often confused with malignant findings [ 3 ].…”

“…Myospherulosis develops as the result of a reaction between exogenous lipids and red blood cells (RBC) of the patient, being the latter injured when perceived as a foreign body by the immune system, triggering the inflammatory response described above [ 4 ]. It is usually an asymptomatic disease but when symptomatic, pain, and swelling of the affected area are the key findings [ 1 ]. The appearance of myospherulosis in various tissues has been described but to our knowledge, there are no cases reported in the literature of pulmonary myospherulosis.…”

Acquired myospherulosis secondary to gluteal augmentation on fine needle aspiration cytology: A diagnostic challenge

“…A subsequent lipid membrane forms a saccular structure or “parent bodies” that encloses spherules of altered erythrocytes (endobodies). A lipogranulomatous reaction to the parent bodies creates the characteristic “partially filled bag of marbles” appearance . Recently, few cases of myospherulosis occurring in other areas of the body such as breast, subcutaneous, and gluteal regions have been reported.…”

“…A lipogranulomatous reaction to the parent bodies creates the characteristic "partially filled bag of marbles" appearance. 2 Recently, few cases of myospherulosis occurring in other areas of the body such as breast, subcutaneous, and gluteal regions [3][4][5][6] have been reported. Acquired myospherulosis can also occur in the setting of injections and tissue trauma.…”

Myospherulosis in Temporal Bone After Surgery Resembles Cholesteatoma on Imaging

“…It is caused by the inter action of extravasated erythrocytes and exogenous or endogenous lipids, and can occur in any part of the body at any age (1). It may be seen in various clinical settings including fat necrosis, difficult differential diagnosis in malignancy (e.g., renal cell carcinoma), and after place ment of topical tetracycline in a petrolatum base into asurgical site.…”