The color of skin: orange diseases of the skin, nails, and mucosa.

Cutaneous disease can present with lesions of all colors of the visible spectrum. Lesions of the skin, nail, and mucous membranes with an orange color can be due to a variety of etiologies. The conditions may appear as purely orange, yellow-orange, red-orange, tan, or brown with an orange hue. The orange color may also present as a transient phase of a disease process. As with all dermatologic pathology, a key way to distinguish orange-colored lesions is by distribution and morphology. The sclera, palate, lips, gingiva, and nails may also be involved. A literature review using PubMed with keywords, including orange, skin, mucosa, cutaneous, xanthoderma, and granuloma, was conducted to gather all dermatologic conditions that can present with an orange color. The relevant diseases were categorized by etiology and include inflammatory, infectious, neoplastic, and exogenous causes.

Compartment syndrome associated with expansile antebrachial tumors in two dogs.

CASE DESCRIPTION: A 10-year-old spayed female Jack Russell Terrier and a 7-year-old neutered male mixed-breed dog were evaluated because of acute, progressive, unilateral forelimb lameness associated with signs of pain and turgid antebrachial swelling. CLINICAL FINDINGS: For either dog, there were no salient pathological or diagnostic imaging abnormalities. A diagnosis of compartment syndrome was confirmed on the basis of high caudal antebrachial compartmental pressure in the affected forelimb. TREATMENT AND OUTCOME: Both dogs underwent surgical exploration of the affected forelimb. In each case, an intramuscular tumor (mast cell tumor in the Jack Russell Terrier and suspected sarcoma in the mixed-breed dog) was detected and presumed to be the cause of the high compartmental pressure. At 6 months following tumor excision, the dog with the mast cell tumor did not have any clinical signs of disease. The dog with a suspected sarcoma underwent tumor excision and forelimb amputation at the proximal portion of the humerus followed by chemotherapy; the dog was euthanized approximately 1 year following treatment because of pulmonary metastasis. CLINICAL RELEVANCE: Compartment syndrome is a serious but rarely reported condition in dogs and is typically ascribed to intracompartmental hemorrhage. These 2 cases illustrate the potential for expansile intramuscular antebrachial tumors to cause compartment syndrome in dogs.

Unilateral intraocular mastocytosis and anterior uveitis in a dog with subcutaneous mast cell tumors.

A 9-year-old male castrated Scottish terrier was referred to the Radiation Oncology Service at the William R. Pritchard Veterinary Medical Teaching Hospital for palliative radiation therapy of an incompletely excised, recurrent subcutaneous mast cell tumor (MCT) located over the right scapula, and surgical removal of a perianal MCT. Three weeks after initial presentation and prior to the fifth radiation treatment, the patient was presented with cloudiness of the left eye of 3-7 days duration. Ophthalmic consultation revealed 3+ aqueous flare with a dependent, swirling component filling approximately one-third of the anterior chamber. Aqueocentesis was performed under general anesthesia. Cytology revealed mast cells with highly atypical morphology and considered most consistent with neoplasia. The patient died 7 months after pathologic diagnosis of MCT on the right shoulder and 2 months after the cytologic diagnosis of malignant mast cells in the left anterior chamber. To the authors' knowledge, this is the first report of intraocular involvement in a mammal with MCTs, described here as intraocular mastocytosis.

Disseminated mast cell tumor infiltrating the sphenoid bone and causing blindness in a dog.

Mast cell tumors are found in most organs and tissues with variable biologic behavior in dogs. This case illustrates the clinical and magnetic resonance imaging (MRI) findings in a dog with disseminated mast cell tumor infiltrating the sphenoid bones. A 6-year-old male neutered Greyhound presented with a 3-day history of acute onset of blindness. General physical examination was normal. Neurological examination revealed mildly disorientated mental status, absent menace response in both eyes, bilaterally decreased vestibulo-oculocephalic reflexes and absent direct and consensual pupillary light reflex in both eyes. An electroretinogram indicated normal retinal function in both eyes. A lesion involving the middle and rostral cranial fossa was suspected. Hematology and serum biochemistry were normal except decreased urea (1.2 mmol/L). MRI of the head revealed heterogeneous signal intensity of the sphenoid bones on T2-weighted images and loss of their normal internal architecture. Cerebrospinal fluid analysis was normal. Abdominal ultrasound revealed hepatosplenomegaly and mesenteric lymphadenopathy. Fine needle aspirates were taken from the jejunal lymph nodes and the spleen. Results were consistent with disseminated mast cell tumor. The owner declined any treatment and the dog was euthanatized. Postmortem examination confirmed disseminated mast cell tumor affecting multiple organs, including the sphenoid bones. To our knowledge, this is the first case describing MRI features of disseminated mast cell tumor affecting the sphenoid bones and causing acute onset of blindness in a dog.

Flushing and increase of serum tryptase after mechanical irritation of a solitary mastocytoma.

Solitary mastocytomas are infiltrates of mast cells in the upper corium, appearing at any side of the body as brownish-reddish plaques in the first months of life. Their course is benign with a spontaneous regression in most cases. A 5-month-old boy presented a 5 x 3 cm sized brownish-yellow plaque on the back of his right hand. His parents reported repeated episodes of swelling and blistering of the skin lesion as well as recurrent systemic flush-reactions. General laboratory parameters were without pathological findings including a normal serum tryptase (5.5 microg/L). A few minutes after rubbing, the lesion became urticarially swollen and the infant developed a general flush reaction accompanied by a bilateral miosis and asthma-like symptoms which disappeared completely after oral administration of 7 drops of dimentinden. Assessment of the serum tryptase two hours after the provocation revealed a more than 5-fold increase (29.3 microg/L) compared to the basic value. We conclude that uncontrolled stroking of mastocytomas should be avoided in patients with a systemic reaction in their history, since this case demonstrates that despite its limited size, mechanical irritation of a solitary mastocytoma may induce strong systemic symptoms as witnessed by transient increase of the serum tryptase, which to our knowledge has not been described in the literature before.

A 6-month old with total body flushing and a macular-papular lesion.

Flushing of the skin of an infant may be a sign of the child's first allergic reaction to food, insect envenomation, or other allergens, a sign of sepsis, or due to dilation of cutaneous vessels caused by a vasodilator substance or neural mechanisms. A rare cause of this condition results in the release of mast cell mediators such as histamine, prostaglandin D2, tryptase, chymase, and leukotrienes. We present a case of a 6-month-old with severe total body flushing and a yellow-tan, raised, well-demarcated lesion on the thigh consistent with a solitary mastocytoma. Erythema was most pronounced adjacent to the lesion, suggesting a positive Darier sign. Subsequent evaluation by a dermatologist confirmed the diagnosis, and the patient underwent no further therapy; however, the family was appropriately counseled on management if the symptoms were to reappear. Appropriate diagnosis and management of this patient and other forms of mastocytosis in children are discussed.

Combined mastocytoma-junctional nevus.

A unique combined mastocytoma-junctional nevus presented as a 4-mm dark brown macule in the axilla of a 57-year-old white female. Histopathologic examination revealed a proliferation of mast cells partially or completely filling the dermal papillae, hyperpigmentation of the basal keratinocytes and mildly increased basal melanocytes. Overlying the mast cell proliferation, pigmented junctional nevus nests were present. The mast cells were strongly positive with Giemsa stain and mast cell tryptase immunohistochemical stain; nevomelanocytic cells were negative. Nevomelanocytes were strongly immunoreactive for S100, HMB-45, Mart-1, and tyrosinase; mast cells were negative. The clinicopathologic features suggested a synchronous proliferation of 2 cell types in the same small cutaneous field rather than a collision tumor. While the cutaneous mast cells probably originated as a disseminated clone, it is postulated that local mast cell growth factor induced nevomelanocytic proliferation and modulated mast cell growth. In fact, the tumor exhibited strong immunoreactivity for the mast cell growth factor receptor (CD117) in mast cells, basal melanocytes, and nevus nests. The incidence of dual mast cell-melanocytic tumors appears to be very low, as only 3 total cases have now been reported. However, since in patients with multiple mastocytomas only a small fraction of lesions are biopsied, the true incidence may be higher than supposed.

[Coexistence of pigmented urticaria and mastocytomas: a case report]. / Wspólistnienie pokrzywki barwnikowej ze zmianami typu mastocytoma--opis przypadku.

Mastocytoses are a heterogeneous group of disorders of unknown etiology characterised by the accumulation of mast cells, particularly in the skin. Mastocytosis may be limited to the skin or involve internal organs, especially those playing the lymphoreticular function. We present a case of 9-year-old girl, with a history of maculopapules at the age of two, followed by yellow-brownish, nodular skin lesions. The skin lesions, located on the trunk, neck and face were accompanied by pruritus. The histopathological examination of the node confirmed the diagnosis of mastocytoma. A bone scintigram showed an increased uptake of radiotechnetium around the right coxal region. Application of antihistaminic drugs and phototherapy (UVA) has led to partial remission of skin manifestations of the disease. A long-term follow-up of the child is necessary.