Unique Case of Parathyroid Adenoma With Arteriovenous Malformation.

Direct communication between dysmorphic arteries and veins without an interceding capillary segment is known as arteriovenous malformation (AVM). Its etiology is still unknown; however, it is commonly acknowledged that it could be related to trauma or is congenital in origin. Often, AVMs are found in the central nervous system or other sites such as under the skin or in the deep solid organs. They can be encountered as a solitary abnormality or associated with another pathology. If they are large enough, they can deprive the neighboring tissue of oxygen, eventually leading to tissue damage and compressing the surrounding organs, causing potentially more serious consequences. AVM in parathyroid adenoma is an unusual entity in the medical reports and known clinical practice. We herein report a unique case of a 49-year-old female patient who presented with a neck mass and associated symptoms of hyperparathyroidism (HPT) with no history of previous trauma or surgery. The imaging and laboratory tests were consistent with parathyroid neoplasm. Parathyroidectomy was performed and revealed parathyroid adenoma with AVM.

Gastric Schwannoma as an Important and Infrequent Differential Diagnosis of Gastric Mesenchymal Tumours: A Case Report and Review of Literature.

The spectrum for gastrointestinal tract mesenchymal tumours includes leiomyomas, leiomyosarcomas, gastrointestinal stromal tumours (GISTs) and schwannomas. Schwannomas (also known as neuroma, neurilemmomas or neurinomas of Verocay) are well-known slow-growing, benign neoplasms that originate from nerve plexuses within a Schwann cell sheath. They can arise anywhere along the course of the peripheral nerve and are frequently reported around the head and neck, brachial plexus and along the gastrointestinal tract. Usually, these tumours are detected as solitary; however, they can occur at multiple sites around the body. Schwannomatosis (multiple schwannomas) is usually associated with neurofibromatosis type 2; the pathogenesis is triggered by mutations of the neurofibromatosis 2 tumour suppressor gene resulting in a loss of its function. Solitary gastric schwannomas are rare lesions that arise from the nerve plexus of the gastric wall. Frequently they are detected incidentally or may present with nonspecific abdominal pain or bleeding. This paper reports the case of a 79-year-old patient diagnosed with gastric schwannoma after presenting with abdominal pain. Gastric schwannomas should be taken into consideration while making a differential diagnosis of lesions that are gastric mesenchymal tumours, which span a broad spectrum. Gastric schwannomas are typically benign, considerably less common than gastric GISTs, and have an excellent prognosis following excision.

Russell Body Typhlitis: A Case Report and Literature Review.

Russell bodies are accumulation of immunoglobulin in plasma cells forming intracytoplasmic inclusions. Russell body colitis is rare with only 3 cases described in the English literature up to date. We report a 78-year-old male with cirrhosis showing prominent cecal infiltration of Russell body containing plasma cells. Plasma cells showed no nuclear atypia or mitoses, and no evidence of light chain restriction. In this article, we report a fourth case of Russell body colitis, that is unique in being localized to the cecum in contrast to the other 3, 1 of which was in an inflammatory polyp in the sigmoid colon, 1 in a rectal tubulovillous adenoma and 1 as part of diffuse gastrointestinal disease. This is therefore the first report of localized Russell body typhlitis, occurring in a cirrhotic patient in whom an adjacent erosion was likely nonsteroidal anti-inflammatory drug-associated, a combination that may have facilitated the formation of Russell bodies.

Colonic Goblet Cell Carcinoid: Rarity of a Rarity! A Case Report and Review of Literature.

Goblet cell carcinoids (GCC) are extremelyrare neuroendocrine tumours, and characterised by their unique combination of two types of cancer cells âÃÂ" neuroendocrine (carcinoid) and epithelial (adeno-carcinoma). In spite of the fact that GCC is regarded as Neuro-Endocrine Tumour (NET), it does not illicit carcinoid syndrome. GCC usually arises in the appendix and accounting for less than 14% of all appendiceal tumours.Primary extra-appendiceal GCC have been reported as stomach, duodenum, small intestine, colon and rectum. The paper presents a rare case of GCC of the ascending colon in a 57-year-old male.

Crusted scabies in a renal transplant recipient treated with daily ivermectin: A case report and literature review.

Crusted scabies is a rare disease variant associated with T-cell dysregulation. Transplant patients are at risk of developing crusted scabies as a consequence of their immunosuppressive regimens. We report a case of crusted scabies presenting with recurrent septicemia in a 65-year-old renal transplant recipient, treated with daily ivermectin for 7 days after initial failure of weekly ivermectin dosing. A literature review of crusted scabies in transplant recipients consisting of 19 cases reports was summarized. Pruritus was common, and initial misdiagnosis was frequent. Most were treated with topical therapy, with one-third receiving ivermectin. Three of seven cases presenting with a concomitant infection died. Crusted scabies is commonly misdiagnosed in transplant recipients owing to its rarity, varied appearance, and different skin distributions. It should be considered in the differential diagnosis of transplant recipients presenting with rash and pruritus, given its association with secondary infection and subsequent mortality.

Pulmonary Intravascular B-Cell Lymphoma with Angiotropism/Angioinvasion Mimicking Interstitial Lung Disease: A Clinical Dilemma and Potential Diagnostic Challenge.

Intravascular large B cell lymphoma (IVLBCL) is a rare type of extranodal diffuse large B-cell lymphoma. Patients typically present with nonspecific findings, particularly bizarre neurologic symptoms, fever, and skin lesions. IVLBCL with primary lung presentation is very rare and difficult to diagnose. The authors report a case of a 75-year-old male who presented with neurological symptoms and showed diffuse pulmonary ground glass opacities on computed tomography scan (CT scan). Surgical lung biopsy was performed. Light microscopic examination of the specimen showed diffuse alveolar septal widening caused by neoplastic lymphocytes, which were positive for CD20. These atypical lymphoid cells also demonstrated angiotropism/angioinvasion of the medium sized pulmonary vessels. The patient was diagnosed with IVLBCL and underwent chemotherapy. The patient is still alive 12 months after diagnosis.

Pulmonary Alveolar Proteinosis in Setting of Inhaled Toxin Exposure and Chronic Substance Abuse.

Pulmonary alveolar proteinosis (PAP) is a rare lung disorder in which defects in alveolar macrophage maturation or function lead to the accumulation of proteinaceous surfactant in alveolar space, resulting in impaired gas exchange and hypoxemia. PAP is categorized into three types: hereditary, autoimmune, and secondary. We report a case of secondary PAP in a 47-year-old man, whose risk factors include occupational exposure to inhaled toxins, especially aluminum dust, the use of anabolic steroids, and alcohol abuse, which in mice leads to alveolar macrophage dysfunction through a zinc-dependent mechanism that inhibits granulocyte macrophage-colony stimulating factor (GM-CSF) receptor signalling. Although the rarity and vague clinical presentation of PAP can pose diagnostic challenges, clinician awareness of PAP risk factors may facilitate the diagnostic process and lead to more prompt treatment.

Intra-articular solitary fibrous tumor of the knee.

A rare case of intra-articular solitary fibrous tumor of the knee in an 84-year-old man is presented. This case report illustrates that solitary fibrous tumor should be included in the extended differential diagnosis of an intra-articular soft tissue mass.

Proximal Phalanx Osteoid Osteoma: A Case Report and Literature Review.

Osteoid osteoma is a rare clinical entity often mistaken for osteomyelitis, enchondroma, osteochondroma and other bony pathologies. Cardinal features include localized swelling and nocturnal pain often relieved by nonsteroidal antiinflammatory drugs. Definitive treatment requires surgical removal of the lesion by curettage or en bloc excision. The following case report details the diagnosis and management of a recurrent case of osteoid osteoma in a long finger proximal phalanx. Included with this case report is a literature review of osteoid osteomas on the hand and the anatomic distribution of 289 cases published in the last 30 years.

Endocrine Mucin-Producing Sweat Gland Carcinoma, a Histological Challenge.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare adnexal tumor of the skin with low-grade cytological features and neuroendocrine differentiation. It has a predilection for the skin of the eyelid, but has also been reported in the face and rarely extra-facial locations. The tumor is seen more frequently in women and on average affects the elderly. It is histologically and immunohistochemically analogous to solid papillary carcinoma of the breast/endocrine ductal carcinoma in situ with a nodular, solid, papillary, and/or cribriforming architecture, neuroendocrine differentiation, and mucin production. Since it was first described by Flieder et al. in 1997, less than 60 cases have been reported in literature. We describe the morphological and immunohistochemical features of another case with a review of the common histological differential diagnoses and emphasize the salient features that help distinguish this rare neoplasm.

A Case of Patch Stage of Kaposi's Sarcoma and Discussion of the Differential Diagnosis.

A 55 year old HIV positive male had a skin lesion biopsy which showed atypical vascular proliferation within the superficial and deep dermis with mild atypia of lining endothelial cells. A sparse lymphoplasmacytic infiltrate surrounding the irregular vascular channels was noted. Immunohistochemistry highlighted the atypical blood vessels with the vascular markers CD31, CD34 and Factor VIII. The differential diagnosis included unusual vascular or lymphatic proliferations, stasis dermatitis, kaposiform hemangioendothelioma, progressive lymphangioma and angiosarcoma with focal Kaposi's sarcoma features. Characteristic human herpes virus-8 positive staining helped support the diagnosis of patch stage of Kaposi's sarcoma. Herein, we discuss the case findings, differential diagnosis and characteristic histological findings associated with the patch stage of Kaposi's sarcoma which can be an elusive diagnosis.

Amelanotic Melanoma Presenting with Plasmacytoid Morphology and BRAF V600 Mutation.

Plasmacytoid melanoma is an unusual variant of malignant melanoma. The plasmacytoid morphology can be found in a variety of other malignancies including carcinomas, plasma cell neoplasms, lymphoproliferative disorders, and sarcomas. The authors report a rare case of plasmacytoid amelanotic malignant melanoma in a 78-year-old man presenting with an enlarging palpable, erythematous mass on his left posterior shoulder. A fine needle aspirate showed atypical findings with single amelanotic cells with high nuclear to cytoplasmic ratio, mono- and multi-nucleation with prominent nucleoli and intranuclear inclusions. Review of the excision and immunohistochemical analysis revealed the malignant plasmacytoid cells stained with vimentin, S-100, HMB-45, and other staining patterns consistent with melanoma. Initial evaluation was negative for other sites of disease. However, 4 months later, the patient was noted to have metastatic disease to his lungs and liver. Given that the tumor was noted to be BRAF V600R mutated, the patient was started on single agent dabrafenib. The plasmacytoid morphology can be found in a variety of malignancies. Melanoma should be considered in the differential diagnosis of any malignancy presenting with plasmacytoid features.

Primary cutaneous versus salivary gland origin mucoepidermoid carcinoma.

Mucoepidermoid carcinoma (MEC) is a malignant glandular epithelial neoplasm that most commonly arises in the major salivary glands. Primary cutaneous MEC is very rare. There is a particular diagnostic challenge in determining the primary site of MEC when it is found in skin overlying the parotid gland. Attention to a combination of morphologic findings may be helpful. However, differentiation of primary cutaneous MEC from secondary cutaneous involvement by a parotid MEC may be unnecessary once the parotid gland is infiltrated. We report the case of a 54-year-old male with a 2-cm asymptomatic mass overlying the right parotid gland, which was managed by excision of the affected skin, right total parotidectomy, and right neck dissection. Histopathologic and immunohistochemical findings were consistent with a cutaneous intermediate-grade MEC. Postoperative radiotherapy was deferred. The patient showed no evidence of recurrence or metastasis at 2 months before self-discontinuing follow-up. To our knowledge, this is only the second reported case of MEC involving the parotid gland, but of overlying primary cutaneous origin.

Signet-ring cell melanoma: a potential diagnostic pitfall.

Malignant melanoma is commonly known as the great mimicker and can present in various clinical manifestations and with diverse morphological variants. One of the rare histological variants is the signet-ring cell type. The signet-ring morphology has been reported in numerous other neoplasms including adenocarcinoma, lymphoma, liposarcoma, squamous cell carcinoma, and basal cell carcinoma. We report a rare case of primary signet-ring cell malignant melanoma in a 62-year-old man. He initially presented with an enlarging nevus on his right flank with surrounding erythema. A biopsy showed atypical epithelioid and signet cells with prominent nucleoli and occasional mitoses. Initial diagnosis favored metastatic signet-cell carcinoma of gastrointestinal origin. Review of the biopsy and immunohistochemical analysis revealed the malignant signet-ring cells stained with S100, vimentin, and melanoma cocktail, in keeping with melanoma. The signet-cell morphology can be found in a variety of other malignancies. To prevent potential misdiagnoses, thorough histological examination should be aided by an appropriate immunohistochemical panel to confirm melanoma and exclude erroneous differentials.

Cutaneous lymphadenoma: a rare case and brief review of a diagnostic pitfall.

We report a case of cutaneous lymphadenoma on the posterior left ear of a 67-year-old woman. Although it is benign, recognition of cutaneous lymphadenoma is important as it presents a diagnostic pitfall to the unsuspecting dermatologist and general surgical pathologist, who may readily misdiagnose the lesion because it is not only very rare, but also clinically and histologically resembles the far more common and locally destructive basal cell carcinoma.

Cylindroma with Stromal Adipose Tissue Metaplasia versus Arising in a Background of Nevus Lipomatosus.

Nevus lipomatosus superficialis is a rare type of connective tissue nevus. Cylindroma is a benign skin appendage tumor with a predilection for the scalp of older females. We describe the case of a 56-year-old woman with a scalp lesion demonstrating histopathologic features consistent with benign cylindroma arising within a nevus lipomatosus superficialis. To our knowledge, this lesion has not been raised in the literature in the differential for cylindroma with what is presumed to be stromal adipose metaplasia.