Dear Editor,
Rhinosporidiosis is a chronic granulomatous disorder of infective etiology caused by Rhinosporidium seeberi, the taxonomy of which is highly debatable. Recent studies have suggested a cyanobacterium Microcystis aeruginosa to be the causative organism. It commonly manifests as sessile or pedunculated vascular polyps in nasal mucosa, nasopharynx, and soft palate. Although rare, cutaneous involvement has multifaceted morphology and is usually associated with mucosal lesions. We hereby report a case of a middle-aged male having disseminated cutaneous rhinosporidiosis and thrombocytopenia, which after failed medical management was treated by surgical intervention.
A 37-year-old male who had a habit of bathing in a pond regularly, presented to our outpatient department with multiple polymorphous nodules, variable in size present over face, chest, forearms, and lower limbs for last 9 months. The patient had history of epistaxis 5 years ago for which he was operated elsewhere and some polypoidal lesions were removed after which he had an uneventful course. Three months ago, he visited another hospital where a nodule over his left forearm and another over his left leg were excised, but evidence of regrowth in their vicinity was seen after few weeks. Cutaneous examination revealed four sessile, friable nodules with erosion and hemorrhagic crusting over face, largest of them measuring 4 × 3 cm [Figure 1b]. Brownish pink nodules and plaques were present over right side of upper chest and left forearm [Figure 1a]. Multiple, firm and large subcutaneous nodules mimicking soft tissue tumors were seen over left lower thigh and both legs [Figure 1c and 1d], largest of them measuring 15 × 10 cm present over the right calf. They were not fixed to underlying structures and there was minimal sign of inflammation. Systemic examination revealed no abnormality.
Figure 1: (a). Brownish pink nodule and plaque over left forearm, (b). Highly vascular, sessile, friable nodules with erosion and hemorrhagic crusting over face, (c and d). Giant subcutaneous nodules over lower extremities
Complete hemogram showed thrombocytopenia (50,000/cumm). Other routine blood parameters including blood sugar and imaging (x ray chest, abdominal ultrasonography, computed tomography chest and abdomen) were normal. Serology for HIV, hepatitis, and syphilis was negative. Total immunoglobulin level and CD4 counts were also normal. Incisional biopsy done from a nodule over chest, on hematoxylin-eosin (H&E) staining revealed hyperplastic stratified squamous epithelium with multiple sporangia in various stages of development containing numerous endospores [Figure 2a]. They also stained positively for periodic acid Schiff (PAS) and gomori methenamine silver (GMS) [Figure 2b and 2c]. Based upon the characteristic histological findings, diagnosis of disseminated cutaneous rhinosporidiosis was made. The patient was referred to ENT department for endoscopic examination which demonstrated a small sessile polyp in right torus tubarius area of nasopharynx.
Figure 2: (a). Sporangia in various stages of maturation containing endospores, (H & E 10x) (b). PAS-stained smear showing sporangia containing endospores, (10x) (c). GMS-stained smear showing sporangia containing endospores (40x)
We started the patient on dapsone tablet 100 mg once a day, and liposomal amphotericin B injection was given intravenously daily by slow infusion in a dose of 3 mg/kg. Hypokalemia was encountered which was corrected. We continued this treatment for 4 weeks but there was minimal reduction of size of lesions. During this period, platelet counts were fluctuating (25,000--66,000) but there were no bleeding manifestations.
Bone marrow aspiration and biopsy was done which revealed marginally increased number of megakaryocytes and no dyspoietic changes in any lineage. PAS and GMS staining of marrow aspirate did not display any spores, and bacterial and fungal culture did not show any growth. Hematologists were not in favor of starting any treatment for thrombocytopenia as the patient was compensating well. Subsequently, injection caspofungin was given (50 mg IV once daily) for 2 weeks but there was no clinical improvement. The patient was eventually managed by surgical excision of large nodules over legs [Figure 3a and 3b] when platelet counts improved (1 lakh/cumm). Rest of the cutaneous lesions and the nasopharyngeal polyp are scheduled to be excised. Currently his platelet count (2.2 lakhs/cumm) is also within normal limit.
Figure 3: After surgical excision of masses over (a). right leg and (b). left leg
Rhinosporidiosis is a rare chronic granulomatous disease caused by Rhinosporidium seeberi. Sessile or pedunculated polyps affecting nose and nasopharynx is the most common presentation. There are predominantly three modes of cutaneous transmission;[1] autoinoculation, hematogenous transmission, and direct implantation. Cutaneous dissemination has been reported to occur in immunocompetent[2] as well as immunosuppressed[3] patients. Visceral involvement albeit rare, has been reported to occur in the form of pulmonary affection as reported by Kumari et al.[4] and Ghosh et al.[1] Cutaneous rhinosporidiosis has protean manifestations. Literature review shows tumor like nodules, warty papules and plaques, subcutaneous nodules and giant masses resembling soft tissue tumors to be the most common presentation.[5] The condition remains a major therapeutic challenge. Medical management has been mostly frustrating. Only dapsone has some role as an adjunct to surgical management in preventing recurrences. Thus, surgical excision remains the treatment of choice.
We are reporting this case due to the simultaneous occurrence of nasopharyngeal and disseminated cutaneous lesions in the form of subcutaneous nodules and plaques and friable growth which is a rare presentation. Any disseminated fungal infection occurs through the blood stream and seeding of bone marrow which may be responsible for thrombocytopenia as encountered in our patient. Intravenous antifungal may have caused resolution of the bone marrow lesions leading to an improved platelet count, and may have resulted in the absence of any organism in marrow aspirate.
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References
1. Ghosh R, Mondal S, Roy D, Ray A, Mandal A, Benito-León J. A case of primary disseminated rhinosporidiosis and dapsone-induced autoimmune hemolytic anemia:A therapeutic misadventure. IDCases 2021;24:e01076
2. Tolat SN, Gokhale NR, Belgaumkar VA, Pradhan SN, Birud NR. Disseminated cutaneous rhinosporidiosis in an immunocompetent male. Indian J Dermatol Venerol Leprol 2007;73:343–5
3. Padmavathy L, Rao IL, Selvam SS, Sahoo CG. Disseminated cutaneous rhinosporidiosis in a HIV sero-positive patient. Indian J Dermatol Venerol Leprol 2001;67:332–3
4. Kumari R, Nath AK, Rajalakshmi R, Adityan B, Thappa DM. Disseminated cutaneous rhinosporidiosis:Varied morphological appearances on the skin. Indian J Dermatol Venerol Leprol 2009;75:68–71
5. Sen S, Agrawal W, Das S, Nayak PS. Disseminated cutaneous rhinosporidiosis:Revisited. Indian J Dermatol 2020;65:204–7