Background: Talaromycosis (penicillinosis) is multiresistent opportunistic mycosis. The infection can be inapparent and it can simmulate malignant tumor dissemination in some patients. Case: We present a case of 33-years-old patient with mucinous adenocarcinoma of left ovary, initially FIGO IIC. The patient had had hysterectomy, bilateral adnexectomy, omentectomy and port-site metastasis extirpation. Six cycles of 1st chemotherapy paclitaxel and carboplatin had been administered to patient following the surgery. Positron emission tomography / computed tomography (PET/CT) scan after the treatment, had shown metabolic activity infiltrating both lung apexes, supposedly with no disease correlation, and hypermetabolic foci in spleen, suspicious of being metastases. Pacient showed no clinical symptoms, nor markers of inflammation elevation. Initially elevated serum tumor markers CA125 and CA72-4 had decreased after the treatment. Bronchoalveolar lavage cytology described presence of inflammatory infiltration with fungiforming hyphae – most probably an aspergillosis. Mannan and galactomannan serology was negative. In regard to splenectomy plans, treatment with voriconazol was initiated empirically. Result of fungi cultivation out of bronchoalveolar lavage was finalized later, showing sporadic presence o Penicillium sp. with resistance to antimycotic treatment except for amphotericin B. Liposomal amphotericin B treatment was administered in two cures, 28 days in total. Immunomodulatory treatment of secondary cellular immunodeficiency and vaccination against encapsulated bacteria was given to the patient. Splenectomy was performed 6 months after the end of chemotherapy treatment. Histopathology showed chronic granulomatous inflammation without mycotic hyphae, with no evidence of tumor cells. After the splenectomy, patient was treated by surgical incision and drainage and by klindamycin for intraabdominal abscess in left hypogastric area. Conclusion: Patient is under follow up by oncologist, immunologist and gynecologist 12 months after the splenectomy, she is surveilled by PET/CT and serum tumor markers. Talaromycosis can be clinically inapparent in spite of its dissemination. It can be present in diffuse, granulomatous and mixed form. Therapeutic agent is sometimes limited to amphotericin B due to its resistence. Liposomal form of amphotericin B is recommended regarding its pharmacokinetic properties. In case of dissemination, administration period of more than 14 days is recommended, even in inapparent form. Immunomodulatory treatment is recommended due to opportunistic infection.