Rosai- Dorfman Disease is a rare benign histiocytic disorder in which patients present with painless cervical lymphadenopathy, fever and leukocytosis. The classical findings include emperipolesis and histiocytes staining positive for S100 protein and CD68 and negative for CD1a.
Aggressive angiomyxoma is a locally aggressive mesenchymal tumour.
This tumour usually occurs in women of reproductive age and is located in the perineal or pelvic region.
Histologically, this enigmatic soft tissue tumour is characterized by a prominent myxoid matrix and numerous thin-walled blood vessels.
Myxofibrosarcoma, is the most common soft tissue sarcoma in the extremities of the elderly patients ( between sixty and eighty years of age).
Histopathologically, the tumour is characterized by spindle cellular proliferation with moderate cellular density in fibromyxoid stroma.
Source: De Castro BAC, Piancastelli ACC, Meyer RLB, Piancastelli PM, Ribeiro CA, Miranda RMC. Myxofibrosarcoma – Case report. Anais Brasileiros de Dermatologia. 2016;91(1):97-99. doi:10.1590/abd1806-4841.20163922.
Superficial acral fibromyxoma (SAF) is a fibromyxoid tumor with a predilection for the hands and feet, which was first described in 2001.
Superficial acral fibromyxoma most often presents as a slow-growing, nodular mass at acral sites.
Previously published series suggest that the toes are more commonly affected than the fingers, with the majority involving the subungual or periungual region; however, the heel, palm, and ankle can also be affected.
Males are affected approximately twice as often as females, with the average age of presentation in the fifth to sixth decade of life.
Most tumors are asymptomatic or only mildly tender with pressure, often leading to a delay in patients seeking medical treatment.
Management of these tumors typically involves complete excision to rule out malignancy and prevent recurrence.
The gross appearance of the tumor is typically a firm, nodular, or lobulated mass with a whitish cut surface that can range from solid to gelatinous.
The tumor usually involves the dermis, often with extension into the subcutaneous tissue.
Occasionally, extension to the fascia or periosteum can cause pressure erosion of the underlying bone.
The histologic appearance of SAF consists of fibroblast-like cells with a storiform or fascicular pattern embedded in a predominantly myxoid, myxocollagenous, or collagenous matrix.
Increased numbers of ectatic blood vessels and mast cells are commonly seen.
Tumor cells typically express CD34, CD99, vimentin, and epithelial membrane antigen and are negative for cytokeratin, muscle, and melanocytic markers.
Park S-W, Kim J-H, Shin H-T, et al. Superficial Acral Fibromyxoma on the Palm. Annals of Dermatology. 2014;26(1):123-124. doi:10.5021/ad.2014.26.1.123.
Calcifying aponeurotic fibroma (CAF) is a rare, locally aggressive fibroblastic lesion that occurs predominantly in the distal extremities of children and adolescents.
CAF occurs in patients over a wide age range; however, it is most common in children and adolescents . The median ages for male and female patients are 11 and 12 years, respectively.
CAF grows in a diffuse, poorly circumscribed manner and is often attached to the aponeurosis, tendons or fascia. Complete local excision is the treatment of choice.
The histological examination of the lesion reveals two components:
i) Fibromatosis-like spindle-shaped cell elements, and ii) nodules of calcification, accompanied by more rounded, epithelioid cells.
Two phases have been described in the development of CAF ; in the initial phase the tumor has an infiltrative growth and often lacks calcification, whilst in the later phase the tumor is more compact and nodular and exhibits a more prominent degree of calcification and cartilage formation, as seen in the present case.
The pathogenesis of CAF remains uncertain; however, a fibroblastic/myofibroblastic origin has been suggested . It has been previously demonstrated using immunohistochemistry that the tumor cells usually express vimentin and smooth muscle actin, but are negative for desmin , and these results are in accordance with this proposal.
Source: NISHIO J, INAMITSU H, IWASAKI H, HAYASHI H, NAITO M. Calcifying aponeurotic fibroma of the finger in an elderly patient: CT and MRI findings with pathologic correlation. Experimental and Therapeutic Medicine. 2014;8(3):841-843. doi:10.3892/etm.2014.1838.