|Year : 2015 | Volume
| Issue : 1 | Page : 18-22
Unusual manifestation of isolated cutaneous toxoplasmosis in an immunocompetent patient
Shirish Nandedkar1, Trupti Bajpai2, Kamal Malukani1, Ganesh S Bhatambare2
1 Department of Pathology, Sri Aurobindo Institute of Medical Sciences, Medical College and Post Graduate Institute, Indore, Madhya Pradesh, India
2 Department of Microbiology, Sri Aurobindo Institute of Medical Sciences, Medical College and Post Graduate Institute, Indore, Madhya Pradesh, India
|Date of Web Publication||16-Jul-2015|
Asst. Prof. Trupti Bajpai
Department of Microbiology, Sri Aurobindo Institute of Medical Sciences, Medical College and Post Graduate Institute, MR-10 Crossing, Indore-Ujjain Road, Indore, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
A rare and probably the first documented case of isolated cutaneous toxoplasmosis is being reported in a 50-year-old, vegetarian, immunocompetent man. The granulomatous nodule located on the scrotal skin was excised, and the sections and crushed material of the nodule were subjected to different staining techniques. Demonstration of crescentic structures and PAS-positive material confirmed the presence of Toxoplasma gondii. The significantly raised titer of anti-toxoplasma antibodies further supported the diagnosis. The case was successfully managed surgically. No further treatment was advised since the patient was immunocompetent and it was assumed that cell-mediated immunity would further control the proliferation of organisms.
Keywords: Cutaneous, Toxoplasma gondii, toxoplasmosis
|How to cite this article:|
Nandedkar S, Bajpai T, Malukani K, Bhatambare GS. Unusual manifestation of isolated cutaneous toxoplasmosis in an immunocompetent patient. Indian J Dermatopathol Diagn Dermatol 2015;2:18-22
|How to cite this URL:|
Nandedkar S, Bajpai T, Malukani K, Bhatambare GS. Unusual manifestation of isolated cutaneous toxoplasmosis in an immunocompetent patient. Indian J Dermatopathol Diagn Dermatol [serial online] 2015 [cited 2020 Jan 19];2:18-22. Available from: http://www.ijdpdd.com/text.asp?2015/2/1/18/160984
| Introduction|| |
Toxoplasmosis is a common, widespread, asymptomatic infection of warm-blooded animals caused by an obligate, intracellular, coccidian parasite Toxoplasma gondii that occasionally causes illness. Although the domestic cat is the definitive host, virtually any feline or non-feline including humans can serve as an intermediate host. Transmission of infection can occur via ingestion of oocysts from feline feces, ingestion of cysts present in the tissues of infected intermediate hosts and transplacentally via tachyzoites. ,,
Systemic toxoplasmosis has been reported in humans, but cutaneous manifestation of toxoplasmosis is rarely encountered. The first case of cutaneous toxoplasmosis was documented in 1941. , Reviews reveal that the incidence of cutaneous toxoplasmosis is much less than 10%.  Isolated cutaneous lesions in toxoplasmosis are very rare. Most of the cases are associated with systemic involvement in immuno-compromised host. Here, we report a rare and probably the first documented case of isolated cutaneous toxoplasmosis in an immunocompetent man. After careful review of literature, we have highlighted the importance of considering toxoplasmosis in the differential diagnosis of varied dermatological presentations.
| Case Report|| |
A 50-year-old healthy Indian man presented to our outpatient department with a single, hard, non-tender, circumscribed, painless noduleat the base of penis posteriorly on the scrotum. Other body sites were unaffected. The patient gave history of scrotal skin thickening since last 2 months, slowly growing in size. He was a vegetarian Hindu priest and provided no history of sexual contact, drug abuse, hereditary disease, ulcers on penis, access to immunosuppressive agents or association with pets. The patient was afebrile and did not reveal signs of arthralgia, weight loss or visual problems.
Before presenting to the surgical OPD, the patient had taken a course of antibiotic (tablet cefexime 200 mg twice a day) for 15 days without any appreciable effect on the lesion. Excision of the lesion was planned. A complete blood count (CBC), serum biochemical profile and urinalysis were within normal limits. He had no detectable lymphadenopathy and hepatosplenomegaly. Serology for human immunodeficiency virus (HIV) and Hepatitis B surface antigen (HBsAg) were negative. Ultrasonography of the scrotum revealed a faint, homogenous subcutaneous scrotal mass, 4.6 × 2.8 cm in size below the base of penis, which was suspected to be an organized hematoma or fibrolipoma.
The scrotal lesion was excised. The excised tissue received in the surgical pathology department consisted of multiple bits of tissue approximately 7 × 3 × 2 cm. covered with skin [Figure 1]. The skin was unremarkable while the cut surface was greyish white to yellowish, with local areas of necrosis. Microscopic examination of the sections stained with hematoxylin and eosin showed large number of granulomas [Figure 2] with collections of foamy histiocytes [Figure 3] and macrophages showing small inclusions with clear zone around [Figure 4], local areas of necrosis [Figure 5] with giant cells at places. The overlying epidermis was unremarkable.
|Figure 2: H and E-stained (×40) image of tissue section showing granulomas|
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|Figure 3: H and E-stained (×400) image of tissue section showing foamy histiocytes|
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|Figure 4: H and E-stained (×1000) image of tissue section showing macrophages with small inclusions|
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|Figure 5: H and E-stained (×40) image of tissue section showing necrosis|
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The sections and the material obtained after crushing the tissue were subjected to periodic acid-Schiff stain (PAS), Giemsa, Ziehl-Neelsen (ZN), Fite-Faraco, Gram, Gomori's methenamine silver (GMS) and Alizarin red staining. Gram-positive crescentic structures were seen on stained sections [Figure 6] while they were more appreciable on crushed tissue smears [Figure 7]. ZN staining and Fite-Faraco staining did not reveal Acid-fast Bacilli (AFB). However, small rounded acid-fast structures were occasionally visible on tissue sections [Figure 8]. PAS staining revealed PAS-positive material [Figure 9]. The Giemsa-stained tissue sections revealed bluish inclusion bodies. Gomori's methenamine silver stain was negative on inclusion bodies and Alizarin red staining was also negative on tissue sections. Based on these findings, a diagnosis of cutaneous toxoplasmosis was made.
|Figure 6: Gram-stained (×1000) tissue sections showing Gram-positive crescentic structures|
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|Figure 7: Gram-stained (×1000) crushed tissue showing prominent Gram-positive crescentic structures|
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|Figure 8: PAS-stained (×1000) tissue sections showing PAS-positive material|
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|Figure 9: Giemsa-stained (×1000) tissue sections showing inclusion bodies|
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Patient's serum was subjected to ELISA-based anti-toxoplasma antibody (IgG and IgM) detection test (Calbiotech, India). The antibody index value of IgM was 0.9 and that of IgG was 2.1 (reference values: >1.1-positive; 0.9-1.1-borderline; <0.9-negative). The significantly raised titers of IgG further supported the diagnosis. The patient recovered and the surgical wound healed well. Since the patient had no other complaint, no further treatment was advised. He was kept on a regular follow-up along with periodic assessment of anti-toxoplasma antibody.
| Discussion|| |
Dermatological manifestations of toxoplasmosis are rarely encountered. There is great variability in the gross appearance of lesions in cutaneous toxoplasmosis. Several authors have reported macular, hemorrhagic and exfoliative lesions in congenital toxoplasmosis while lesions of different morphologies including macula-papular, papulo-nodular, purpuric, papulo-pustular, hemorrhagic, lichenoid, hyperemic, erythema-multiforme-like, nodular prurigo-like, ulcerative, purpuric telangiectatic dermatosis, fleeting erythematous macules, heliotrope periorbital edema or scaly erythematous plaques, have been described as cutaneous manifestations of acquired acute toxoplasmosis. ,,, The patho-physiological basis of these cutaneous manifestations is still not clear, although it is believed that the varying manifestations are due to heterogenous systemic immune responses rather than a direct response to the parasite. This is supported by the fact that only 50% of cases actually demonstrate the organism in the skin. Furthermore, there are a variety of immune reactions in the lesions, regardless of whether the parasite is found at the site. 
Cases in which patients presented with fever, weight loss, lymphadenopathy and multiple, painful, non-tender nodular lesions on several regions of the body including palms, soles, hands, legs, trunk, face, chest, pinna, etc., have been described. ,,, These symptomatic manifestations are likely to be seen in immunosuppressed individuals. Our patient was an immunocompetent asymptomatic case, with no systemic manifestations, except for the presence of a single, circumscribed, asymptomatic nodule on the scrotal skin. Interestingly, the etiologic agent could also be demonstrated.
Humans usually acquire this infection through ingestion of oocysts deposited in soil or litter pans of cats or by eating meat from chronically infected animals  or through reactivation of a previous latent infection following HIV infection. , The origin of Toxoplasma gondii infection in our case was uncertain. Since our patient was a vegetarian immunocompetent man and provided no history of contact with pets especially cats, we can only assume of an accidental ingestion of oocysts through consumption of contaminated food and water.
On the basis of histopathological evaluation, various possibilities of granulomatous inflammation with inclusions, such as leishmaniasis, histoplasmosis, rhinoscleroma, malakoplakia, leprosy, tuberculosis, granuloma inguinale and toxoplasmosis were considered.
Tissue stages of Toxoplasma are crescentic, measuring about 2-6 microns. During acute infection, rapidly multiplying 'tachyzoites' occupy intracellular vacuoles; parasitized host cells are eventually destroyed. During chronic infection, the slowly multiplying organisms 'bradyzoites' store PAS-positive material and get tightly packed in "cysts". Cysts originate in intra-cellular vacuoles and gradually enlarge beyond the usual size of host cell, thereby pushing the nucleus to the periphery and sometimes causing it to degenerate. Cysts may contain hundreds of bradyzoites. In our case, the stained tissue sections and crushed material revealed crescentic structures and PAS-positive material. The rounded or oval structures packed within the cysts as seen in tissue sections, were distinguished from Leshmania by the absence of a kinetoplast and distinct nucleus. Histoplasmosis was ruled out by the absence of a PAS-positive cell wall of the organism. Pneumocysts are usually smaller (1-3 microns), almost always found in pulmonary alveoli and form distinct cysts that are impregnated by the GMS stain which was negative in our case. A negative GMS stain also ruled out the possibility of any fungal infection. Tuberculosis and leprosy were ruled out by negative ZN and Fite-Faraco stain, while malakoplakia was excluded on the basis of negative Alizarin red staining. Though chances of Trypanosoma in our case were negligible, it was ruled out because leshmanial (amastigote) stages of Trypanosoma cruzi in myofibers have a kinetoplast and do not store PAS-positive material similar to Toxoplasma gondii. Absence of Gram-negative bacilli in the tissue sections and crushed material ruled out rhinoscleroma and granuloma inguinale. Detection of Gram-positive and PAS-positive crescentic inclusions with tissue macrophages lead to diagnosis of Toxoplasmosis which was supported by detection of high level of anti-toxoplasma antibodies in the patient's serum. Although detection of T. gondii DNA by polymerase chain reaction (PCR) is a rapid and reliable method for the diagnosis of Toxoplasmosis; we seek to highlight that microscopy is the gold standard for the diagnosis of parasitological diseases and we were able to demonstrate the parasite by this technique. No treatment was advised following surgery since the patient was immunocompetent and it was assumed that cell-mediated immunity will further control the proliferation of organisms.  However, studies have demonstrated use of anti-toxoplasma therapy with pyrimethamine and sulfadiazine in acute cases even when the Toxoplasma zoites were not demonstrated histologically. 
| Conclusions|| |
In conclusion, the manifestations of cutaneous toxoplasmosis are varied and non-specific. Nonetheless, it is useful to consider this disease in the differential diagnosis of patients with varied dermatological manifestations. Besides serological investigations, diagnosis should be augmented with more specific methods like skin biopsy to demonstrate the etiologic agent. Toxoplasmosis producing a single granulomatous lesion is rare.
The authors wish to thank the Chairperson and Dean of the institute for providing laboratory facilities and healthy working atmosphere during the study period. The authors are also thankful to the technical staff of the institute for providing necessary helping hand during the endeavour.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]