Hepatocellular adenomatosis is a rare entity that may mimic other hepatocellular lesions

A 14-year-old girl presented to her pediatrician with right lower quadrant pain that progressed to right upper quadrant pain with radiation to her back. Her past medical history included mitral valve prolapse, and she had no history of oral contraceptive use. Abdominal computed tomography revealed a liver mass and multiple smaller areas of low attenuation, too small to characterize. The clinical and radiographic features were suggestive of hepatocellular adenoma, and she underwent a left hepatic lobectomy. The liver contained one 4.2 cm nodule and multiple (10 to 20) smaller nodules that were well-demarcated from the adjacent liver parenchyma. All lesions were histologically hepatocellular adenomas and, therefore, she was diagnosed with hepatocellular adenomatosis. This case is unique because of the small number of cases of hepatocellular adenomatosis diagnosed in teenagers, and little long-term follow-up.     

Localized intrapancreatic malignant mesothelioma: a rare entity that may be confused with other pancreatic neoplasms

Malignant mesothelioma usually presents with diffuse involvement of the pleura or peritoneum. Circumscribed or localized malignant mesothelioma has been described in these locations, as well as the viscera, in which case it may cause diagnostic confusion with other, more common entities. Herein, we describe the first well-documented case of primary intrapancreatic malignant mesothelioma in the English literature. The patient was an otherwise healthy 39-year-old woman who presented with a symptomatic mass in the head of the pancreas that was completely resected via pancreaticoduodenectomy. The tumor was composed of cysts, papillae, and tubules lined by cells with abundant eosinophilic cytoplasm and immunohistochemically expressed CA-125, calretinin, and D2-40. Follow-up revealed no evidence of residual or recurrent disease 32 months after surgery. This report also describes the clinical and pathologic characteristics of an intrapancreatic mesothelioma and provides a review of the literature regarding entities that may be considered in the differential diagnosis of this tumor.     

Pancreatic hepatoid carcinoma: A rare form of pancreatic neoplasm

Primary pancreatic hepatoid carcinoma (PHC) is extremely rare, resembling hepatocellular carcinoma (HCC) in terms of morphology and immunohistochemical features. Hepatoid carcinoma can present in other organs, most noticeably in the stomach. PHC is present in two forms either a pure form like HCC or admixed with other histologic tumor components characteristic of the underlying primary site (endocrine tumors, ductal, or acinar adenocarcinomas). Here, we report a 69‐year‐old male patient with distal pancreatic mass incidentally found during a CT scan workup for a pulmonary nodule suspicious for metastatic prostate adenocarcinoma. We described the clinical, cytological, and histological finding and conducted a literature review. Diagn. Cytopathol. 2015;43:251–256. © 2014 Wiley Periodicals, Inc.     

Infections in the gastrointestinal tract that can mimic malignancy

Infections in the gastrointestinal tract can present with the clinical impression of malignancy. These infectious mimics can take on a variety of forms from endoscopically concerning ulcers to large infiltrative masses and may be associated with lymphadenopathy and distant disease that is concerning for metastasis. In such cases, histopathology plays a key role in rendering a diagnosis of infection. In this review, we summarize the common and rare gastrointestinal infectious mimics of malignancy reported in the English medical literature. Microorganisms of all types have been implicated including bacteria, viruses, fungi, and parasites. Common bacterial causes include tuberculosis, actinomycosis, syphilis, and lymphogranuloma venereum. A small number of cases are due to other bacteria such as Helicobacter, Yersinia, α-hemolytic Streptococcus and Rhodococcus. The most common viral mimic of malignancy is cytomegalovirus; however, herpes simplex virus and Epstein-Barr virus have also been reported. Frequent fungal causes include histoplasmosis, mucormycosis and basidiobolomycosis; with a small number of cases due to candidiasis, aspergillosis and paracoccidiomycosis. Parasitic mimics of malignancy are less common. They include mostly protozoal infection such as amebiasis; however, a handful of various helminth infections (anisakiasis, strongyloidiasis, enterobiasis, trichuriasis, schistosomiasis, fascioliasis, echinococcosis) have also been reported. In summary, infectious etiology should be considered in the differential diagnosis of lesions in the gastrointestinal tract that are suspicious for malignancy.     

Uterine hemangioma: a rare pathologic entity

Uterine hemangioma is a rare benign tumor usually presenting with menorrhagia or pregnancy-associated complications. Although the current literature identifies fewer than 50 cases, we in our institution identified 5 similar cases among 3700 patients undergoing total hysterectomy from January 2006 to December 2010. Adenomyosis was the most common preoperative diagnosis among our patients. Vaginal examination, uterine curettage specimens, ultrasonography, and hysterography are usually uninformative, and the definitive diagnosis relies on the final histologic examination. The differential diagnosis includes adenomatoid tumor, lymphangioma, and arteriovenous malformation. Uterine hemangiomas are classified into congenital and acquired. The former is believed to be associated with some hereditary diseases, while the latter is associated with both physical changes and hormone alteration, especially high estrogen level. The best treatment for hemangiomas is unclear. However, it is very important to obtain an accurate diagnosis to prevent overtreatment among reproductive-age women. The prognosis is excellent after hysterectomy.     

Extraskeletal osteogenic sarcoma: a rare entity

A 25-year-old female presented with a rapidly increasing painful swelling around right lower thigh and knee for the last 5 months with distant metastasis in the form of lung involvement. X-ray of the part showed only soft tissue swelling without any bony involvement. A diagnosis of extraskeletal osteosarcoma was made which was confirmed by immunohistochemistry.     

Angiomatoid fibrous histiocytoma: a rare pathologic entity

Angiomatoid fibrous histiocytoma is an unusual tumor, affecting primarily young adults who develop local disease with favorable prognosis. This contrasts with the aggressive natural history of malignant fibrohistiocytoma. We report case of a 9-year-old girl who presented with a tumor mass of soft tissues with an unusual deep location, thereby with non distinctive clinical features. Surgical treatment was performed.     

Metastatic Crohn disease: a rare cutaneous entity

Metastatic Crohn disease is a rare cutaneous disorder characterized by noncaseating, granulomatous skin lesions present at sites anatomically separate from the gastrointestinal tract. It is the least common dermatologic manifestation of Crohn disease, and the differential diagnosis includes numerous similarly appearing, granulomatous skin entities. Males and females appear to be equally affected, and children tend to present with clinical lesions different from those of adults. An integration of clinical information, microscopic findings, and ancillary studies is necessary to accurately diagnose this rare cutaneous disease. Our objective is to review the clinical features, histopathologic characteristics, suggested pathogenesis, differential diagnosis, and current therapeutic options of metastatic Crohn disease.     

Omental anisakiasis: a rare mimic of acute appendicitis

The authors recently encountered a patient with omental anisakiasis who presented with features of acute appendicitis and who made an uneventful recovery following resection of an inflammatory omental mass containing the larva(e). Anisakiasis refers to infestation of humans by species of marine nematode larvae belonging to the subfamily Anisakinae. Although this condition is rarely reported in the United States, it has been well described both in Holland and in the Orient. Several publications in the Japanese literature have detailed the morphology of the parasite and the clinical symptoms of infestation. The source of infestation is most often raw or uncooked fish, the latter widely enjoyed as a foodstuff in the Orient, but less popular in the United States. With the growing popularity of "sushi" bars and the increasing numbers of Americans developing a taste for raw fish, this condition may become more prevalent in the future.     

Primary cardiac rhabdomyosarcoma: definition of a rare entity

Primary cardiac rhabdomyosarcoma (PCR) is a highly malignant tumor that is rarely recognized prior to surgery or necropsy. We present the pathologic findings of a primary atrial rhabdomyosarcoma in an 82-year-old woman and an update on PCR as a clinicopathologic entity. In addition to pleomorphic tumor cells with cross-striations and a positive immunoperoxidase reaction for myoglobin, some areas of our patient's tumor had features of sarcoma botryoides. Electron optic studies showed primitive cells with fibroblastic and/or myoblastic differentiation. A comprehensive study of 77 cases in the international literature yielded new information and perspectives on PCR. The incidence of PCR is bimodal among males, being highest in infancy and early childhood with a secondary peak in the sixth and seventh decades. Females, however, have a single peak incidence in the fifth decade. Septal origin is 35.2% among infants and children but only 5.2% among adults. The predilection for the pediatric age group in conjunction with common septal origin among these patients suggests a congenital form of PCR that may arise from embryonic cell tests.