L iposarcoma is the most common type of sarcoma arising in the retroperitoneum, followed by leiomyosarcoma and malignant fibrous histiocytoma. Males and females are affected approximately equally, with peak prevalence in the 6th and 7th decades. Retroperitoneal liposarcomas are generally large at presentation with nearly 50% being larger than 20 cm at diagnosis. Presenting signs and symptoms are nonspecific, and include increased abdominal girth, early satiety, lower extremity swelling, gastrointestinal obstruction or bleeding and pain. Computerized tomography and magnetic resonance imaging show a mass composed predominantly (greater than 75%) of adipose tissue. 1 Histological subtypes of liposarcoma include well differentiated liposarcoma (WDL) and dedifferentiated liposarcoma (the most common liposarcomas arising in the retroperitoneum), as well as myxoid/round cell liposarcoma, which occurs less frequently at this site. Lipoleiomyosarcoma is a rare variant composed of an admixture of WDL and low grade leiomyosarcoma. 2 Its biological behavior is similar to that of WDL. Cytogenetically, WDL and dedifferentiated liposarcoma are characterized by supernumerary circular (ring) and giant rod chromosomes with amplification of the 12q13-15 region. 1 WDL is a low grade neoplasm that for all practical purposes does not metastasize, but because it is typically deeply located and often large when diagnosed, it is technically difficult to resect completely and tends to recur locally, with reported recurrence rates as high as 91%. 1 Grossly, WDL appears as a solid large well circumscribed lobulated mass composed of yellow to white tissue with white delicate septa ( fig. 1). 1 It is composed predominantly of mature-appearing adipose tissue that can look identical to lipoma but has scattered lipoblasts or cells with enlarged hyperchromatic irregular nuclei ( fig. 2). The presence of lipoblasts or atypical cells is required for diagnosis.Dedifferentiated liposarcoma is composed of WDL and high grade nonlipogenic sarcoma ( fig. 2, inset). Dedifferentiation is much more commonly seen in retroperitoneal liposarcomas than in liposarcomas at other sites, possibly because the duration and size of low grade liposarcomas at this site are greater than at other sites. The risk of dedifferentiation in WDL is approximately 10% to 15% overall and the interval period is variable. In 90% of cases the histological appearance of the dedifferentiated component is simply that of a high grade sarcoma, and it is possible that the majority of cases of so-called malignant fibrous histiocytomas occurring in the retroperitoneum actually represent dedifferentiated liposarcomas. In the remaining 10% of cases the dedifferentiated component resembles fibromatosis or low grade fibrosarcoma. The extent and grade of dedifferentiation do not influence the outcome. Most patients die of local effects of the tumor before distant metastasis becomes evident. 1 Surgical resection of retroperitoneal liposarcoma is recommended when feasible; however, complete excisio...

Highlights Currarino syndrome is a rare congenital disorder characterized by a triad. MRI is the best imaging modality in early diagnosis and follow up for recurrences. The presacral mass can be a malignancy in Currarino syndrome. Both neurosurgery and pediatric surgery are needed in tackling Currarino syndrome.

Malakoplakia is a rare chronic granulomatous disease that may affect many organs, including the lung, brain, adrenal glands, pancreas, bone, and the genitourinary tract. The gastrointestinal tract is the most common site of involvement outside of the urinary tract. Herein, we present a case of a 65-year-old male who presented with abdominal pain and unintentional weight loss. Physical examination findings were unremarkable, but colonoscopy revealed an isolated large, flat, soft, and pale lesion in the transverse colon. Histopathological examination of the lesion showed expansion of the lamina propria due to numerous lymphocytes, plasma cells, neutrophils, and polygonal cells. Von Kossa stain showed small intracytoplasmic basophilic granular inclusions, and these histiocyte cells showed numerous Michaelis-Gutmann bodies, findings considered as diagnostic features of colonic malakoplakia. This is a rare case of isolated malakoplakia of the transverse colon diagnosed on endoscopic specimens. The majority of reported cases have shown an association between systemic diseases and colorectal adenocarcinoma. In addition, most reported cases of colonic involvement have been in the rectum, sigmoid, and right colon.

Linear IgA bullous dermatosis (LAD) is an autoimmune subepidermal blistering disorder. LAD may be either idiopathic or drug related; the most common drug being vancomycin. The clinical presentations of both idiopathic and drug-related LAD are variable and may mimic other blistering disorders. We report a case of a 76-year-old man known to have a renal cell carcinoma who presented a vancomycininduced LAD that clinically mimicked toxic epidermal necrolysis (TEN).